Bump the npm_and_yarn group across 2 directories with 3 updates

Bumps the npm_and_yarn group with 1 update in the / directory: [brace-expansion](https://github.com/juliangruber/brace-expansion).
Bumps the npm_and_yarn group with 1 update in the /tests/ts/bazel_repository_test_dir directory: [lodash](https://github.com/lodash/lodash).


Updates `brace-expansion` from 1.1.12 to 1.1.13
- [Release notes](https://github.com/juliangruber/brace-expansion/releases)
- [Commits](https://github.com/juliangruber/brace-expansion/compare/v1.1.12...v1.1.13)

Updates `picomatch` from 2.3.1 to 4.0.4
- [Release notes](https://github.com/micromatch/picomatch/releases)
- [Changelog](https://github.com/micromatch/picomatch/blob/master/CHANGELOG.md)
- [Commits](https://github.com/micromatch/picomatch/compare/2.3.1...4.0.4)

Updates `lodash` from 4.17.23 to 4.18.1
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](https://github.com/lodash/lodash/compare/4.17.23...4.18.1)

---
updated-dependencies:
- dependency-name: brace-expansion
  dependency-version: 1.1.13
  dependency-type: indirect
  dependency-group: npm_and_yarn
- dependency-name: picomatch
  dependency-version: 4.0.4
  dependency-type: indirect
  dependency-group: npm_and_yarn
- dependency-name: lodash
  dependency-version: 4.18.1
  dependency-type: direct:development
  dependency-group: npm_and_yarn
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/build.yml

@@ -545,7 +545,7 @@ jobs:
       # FIXME: make test script not rely on flatc
       run: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_INSTALL=OFF -DFLATBUFFERS_BUILD_FLATLIB=OFF -DFLATBUFFERS_BUILD_FLATHASH=OFF . && make -j
     - name: pnpm
-      run: npm install -g pnpm esbuild
+      run: npm install -g pnpm
     - name: deps
       run: pnpm i
     - name: compile

docs/source/languages/rust.md

@@ -97,6 +97,61 @@ convenient accessors for all fields, e.g. `hp()`, `mana()`, etc:
 
 *Note: That we never stored a `mana` value, so it will return the default.*
 
+## Fallible API and Custom Allocators
+
+Every `FlatBufferBuilder` method that may allocate has a `try_*` counterpart
+(e.g. `try_create_string`, `try_push`, `try_finish`) that returns
+`Result<T, A::Error>` instead of panicking. This is useful when allocation
+failures must be handled gracefully: for example in `no_std` environments or
+with fixed-capacity buffers.
+
+The existing panicking methods are unchanged and remain the simplest option
+when using the default allocator.
+
+#### Custom allocators
+
+Implement the `Allocator` trait and pass it to `FlatBufferBuilder::new_in()`:
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.rs}
+    use flatbuffers::{Allocator, FlatBufferBuilder};
+
+    struct MyAllocator { /* ... */ }
+
+    unsafe impl Allocator for MyAllocator {
+        type Error = MyError;
+        fn grow_downwards(&mut self) -> Result<(), Self::Error> { /* ... */ }
+        fn len(&self) -> usize { /* ... */ }
+    }
+
+    let alloc = MyAllocator::new(/* ... */);
+    let mut builder = FlatBufferBuilder::new_in(alloc);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The built-in `DefaultAllocator` uses `Vec<u8>` and sets `Error = Infallible`,
+so the `try_*` methods on a default builder can never fail.
+
+#### Example: building a buffer with error propagation
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.rs}
+    fn build<A: flatbuffers::Allocator>(
+        builder: &mut FlatBufferBuilder<A>,
+    ) -> Result<(), A::Error> {
+        let name = builder.try_create_string("Orc")?;
+        let inventory = builder.try_create_vector(&[0u8, 1, 2, 3, 4])?;
+
+        let table_start = builder.start_table();
+        builder.try_push_slot_always(Monster::VT_NAME, name)?;
+        builder.try_push_slot_always(Monster::VT_INVENTORY, inventory)?;
+        builder.try_push_slot(Monster::VT_HP, 80i16, 100)?;
+        let root = builder.try_end_table(table_start)?;
+
+        builder.try_finish(root, None)?;
+        Ok(())
+    }
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+See the `FlatBufferBuilder` rustdoc for the full list of `try_*` methods.
+
 ## Direct memory access
 
 As you can see from the above examples, all elements in a buffer are

grpc/src/compiler/python_generator.cc

@@ -172,6 +172,7 @@ class StubGenerator : public BaseGenerator {
        << "  def __init__(self, channel: grpc.Channel) -> None: ...\n";
 
     for (const RPCCall* method : service->calls.vec) {
+      imports->Import("typing");
       std::string request = "bytes";
       std::string response = "bytes";
 
@@ -183,14 +184,22 @@ class StubGenerator : public BaseGenerator {
         imports->Import(ModuleFor(method->response), response);
       }
 
-      ss << "  def " << method->name << "(self, ";
+      ss << "  def " << method->name << "(\n";
+      ss << "      self,\n";
       if (ClientStreaming(method)) {
-        imports->Import("typing");
-        ss << "request_iterator: typing.Iterator[" << request << "]";
+        ss << "      request_iterator: typing.Iterator[" << request << "]\n";
       } else {
-        ss << "request: " << request;
+        ss << "      request: " << request << ",\n";
       }
-      ss << ") -> ";
+
+      ss << "      timeout: float | None = None,\n";
+      // https://github.com/python/typeshed/blob/ccf9411fb1f5bee2a8e3d278889de17a08f7bbe3/stubs/grpcio/grpc/__init__.pyi#L37
+      ss << "      metadata: typing.Sequence[tuple[str, typing.Union[str, bytes]]] | None = None,\n";
+      ss << "      credentials: grpc.CallCredentials | None = None,\n";
+      ss << "      wait_for_ready: bool | None = None,\n";
+      ss << "      compression: grpc.Compression | None = None\n";
+
+      ss << "  ) -> ";
       if (ServerStreaming(method)) {
         imports->Import("typing");
         ss << "typing.Iterator[" << response << "]";

include/flatbuffers/flexbuffers.h

@@ -1207,11 +1207,20 @@ class Builder FLATBUFFERS_FINAL_CLASS {
     String(str);
   }
 
+  size_t AlignedBlob(const void* data, size_t len, BitWidth alignment) {
+    // The requested alignment must not be smaller than the one required to
+    // store the length.
+    return CreateAlignedBlob(data, len, 0, FBT_BLOB,
+                             std::max(alignment, WidthU(len)));
+  }
+  size_t AlignedBlob(const std::vector<uint8_t>& v, BitWidth alignment) {
+    return AlignedBlob(v.data(), v.size(), alignment);
+  }
   size_t Blob(const void* data, size_t len) {
     return CreateBlob(data, len, 0, FBT_BLOB);
   }
   size_t Blob(const std::vector<uint8_t>& v) {
-    return CreateBlob(v.data(), v.size(), 0, FBT_BLOB);
+    return Blob(v.data(), v.size());
   }
 
   void Blob(const char* key, const void* data, size_t len) {
@@ -1693,11 +1702,16 @@ class Builder FLATBUFFERS_FINAL_CLASS {
 
   size_t CreateBlob(const void* data, size_t len, size_t trailing, Type type) {
     auto bit_width = WidthU(len);
-    auto byte_width = Align(bit_width);
+    return CreateAlignedBlob(data, len, trailing, type, bit_width);
+  }
+
+  size_t CreateAlignedBlob(const void* data, size_t len, size_t trailing,
+                           Type type, BitWidth alignment) {
+    auto byte_width = Align(alignment);
     Write<uint64_t>(len, byte_width);
     auto sloc = buf_.size();
     WriteBytes(data, len + trailing);
-    stack_.push_back(Value(static_cast<uint64_t>(sloc), type, bit_width));
+    stack_.push_back(Value(static_cast<uint64_t>(sloc), type, alignment));
     return sloc;
   }
 

include/flatbuffers/reflection.h

@@ -30,50 +30,52 @@ namespace flatbuffers {
 
 // ------------------------- GETTERS -------------------------
 
-inline bool IsScalar(reflection::BaseType t) {
+constexpr bool IsScalar(reflection::BaseType t) {
   return t >= reflection::UType && t <= reflection::Double;
 }
-inline bool IsInteger(reflection::BaseType t) {
+constexpr bool IsInteger(reflection::BaseType t) {
   return t >= reflection::UType && t <= reflection::ULong;
 }
-inline bool IsFloat(reflection::BaseType t) {
+constexpr bool IsFloat(reflection::BaseType t) {
   return t == reflection::Float || t == reflection::Double;
 }
-inline bool IsLong(reflection::BaseType t) {
+constexpr bool IsLong(reflection::BaseType t) {
   return t == reflection::Long || t == reflection::ULong;
 }
 
-// Size of a basic type, don't use with structs.
-inline size_t GetTypeSize(reflection::BaseType base_type) {
-  // This needs to correspond to the BaseType enum.
-  static size_t sizes[] = {
-      0,  // None
-      1,  // UType
-      1,  // Bool
-      1,  // Byte
-      1,  // UByte
-      2,  // Short
-      2,  // UShort
-      4,  // Int
-      4,  // UInt
-      8,  // Long
-      8,  // ULong
-      4,  // Float
-      8,  // Double
-      4,  // String
-      4,  // Vector
-      4,  // Obj
-      4,  // Union
-      0,  // Array. Only used in structs. 0 was chosen to prevent out-of-bounds
-          // errors.
-      8,  // Vector64
+// This needs to correspond to the BaseType enum.
+constexpr size_t kBaseTypeSize[] = {
+    0,  // None
+    1,  // UType
+    1,  // Bool
+    1,  // Byte
+    1,  // UByte
+    2,  // Short
+    2,  // UShort
+    4,  // Int
+    4,  // UInt
+    8,  // Long
+    8,  // ULong
+    4,  // Float
+    8,  // Double
+    4,  // String
+    4,  // Vector
+    4,  // Obj
+    4,  // Union
+    0,  // Array. Only used in structs. 0 was chosen to prevent out-of-bounds
+        // errors.
+    8,  // Vector64
 
-      0  // MaxBaseType. This must be kept the last entry in this array.
-  };
-  static_assert(sizeof(sizes) / sizeof(size_t) == reflection::MaxBaseType + 1,
-                "Size of sizes[] array does not match the count of BaseType "
-                "enum values.");
-  return sizes[base_type];
+    0  // MaxBaseType. This must be kept the last entry in this array.
+};
+static_assert(sizeof(kBaseTypeSize) / sizeof(size_t) ==
+                  reflection::MaxBaseType + 1,
+              "Size of sizes[] array does not match the count of BaseType "
+              "enum values.");
+
+// Size of a basic type, don't use with structs.
+constexpr size_t GetTypeSize(reflection::BaseType base_type) {
+  return kBaseTypeSize[base_type];
 }
 
 // Same as above, but now correctly returns the size of a struct if
@@ -420,7 +422,7 @@ pointer_inside_vector<T, U> piv(T* ptr, std::vector<U>& vec) {
   return pointer_inside_vector<T, U>(ptr, vec);
 }
 
-inline const char* UnionTypeFieldSuffix() { return "_type"; }
+constexpr const char* UnionTypeFieldSuffix() { return "_type"; }
 
 // Helper to figure out the actual table type a union refers to.
 inline const reflection::Object& GetUnionType(

pnpm-workspace.yaml

@@ -0,0 +1,2 @@
+packages:
+  - tests/ts

rust/flatbuffers/src/builder.rs

@@ -337,22 +337,43 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         self.strings_pool.clear();
     }
 
-    /// Push a Push'able value onto the front of the in-progress data.
-    ///
-    /// This function uses traits to provide a unified API for writing
-    /// scalars, tables, vectors, and WIPOffsets.
+    /// Fallible version of [`push`](Self::push).
     #[inline]
-    pub fn push<P: Push>(&mut self, x: P) -> WIPOffset<P::Output> {
+    pub fn try_push<P: Push>(&mut self, x: P) -> Result<WIPOffset<P::Output>, A::Error> {
         let sz = P::size();
-        self.align(sz, P::alignment());
-        self.make_space(sz);
+        self.align(sz, P::alignment())?;
+        self.make_space(sz)?;
         {
             let (dst, rest) = self.allocator[self.head.range_to_end()].split_at_mut(sz);
             // Safety:
             // Called make_space above
             unsafe { x.push(dst, rest.len()) };
         }
-        WIPOffset::new(self.used_space() as UOffsetT)
+        Ok(WIPOffset::new(self.used_space() as UOffsetT))
+    }
+
+    /// Push a Push'able value onto the front of the in-progress data.
+    ///
+    /// This function uses traits to provide a unified API for writing
+    /// scalars, tables, vectors, and WIPOffsets.
+    #[inline]
+    pub fn push<P: Push>(&mut self, x: P) -> WIPOffset<P::Output> {
+        self.try_push(x).expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`push_slot`](Self::push_slot).
+    #[inline]
+    pub fn try_push_slot<X: Push + PartialEq>(
+        &mut self,
+        slotoff: VOffsetT,
+        x: X,
+        default: X,
+    ) -> Result<(), A::Error> {
+        self.assert_nested("push_slot");
+        if x != default || self.force_defaults {
+            self.try_push_slot_always(slotoff, x)?;
+        }
+        Ok(())
     }
 
     /// Push a Push'able value onto the front of the in-progress data, and
@@ -360,19 +381,29 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     /// the default, then this is a no-op.
     #[inline]
     pub fn push_slot<X: Push + PartialEq>(&mut self, slotoff: VOffsetT, x: X, default: X) {
-        self.assert_nested("push_slot");
-        if x != default || self.force_defaults {
-            self.push_slot_always(slotoff, x);
-        }
+        self.try_push_slot(slotoff, x, default)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`push_slot_always`](Self::push_slot_always).
+    #[inline]
+    pub fn try_push_slot_always<X: Push>(
+        &mut self,
+        slotoff: VOffsetT,
+        x: X,
+    ) -> Result<(), A::Error> {
+        self.assert_nested("push_slot_always");
+        let off = self.try_push(x)?;
+        self.track_field(slotoff, off.value());
+        Ok(())
     }
 
     /// Push a Push'able value onto the front of the in-progress data, and
     /// store a reference to it in the in-progress vtable.
     #[inline]
     pub fn push_slot_always<X: Push>(&mut self, slotoff: VOffsetT, x: X) {
-        self.assert_nested("push_slot_always");
-        let off = self.push(x);
-        self.track_field(slotoff, off.value());
+        self.try_push_slot_always(slotoff, x)
+            .expect("Flatbuffer allocation failure")
     }
 
     /// Retrieve the number of vtables that have been serialized into the
@@ -397,6 +428,22 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         WIPOffset::new(self.used_space() as UOffsetT)
     }
 
+    /// Fallible version of [`end_table`](Self::end_table).
+    #[inline]
+    pub fn try_end_table(
+        &mut self,
+        off: WIPOffset<TableUnfinishedWIPOffset>,
+    ) -> Result<WIPOffset<TableFinishedWIPOffset>, A::Error> {
+        self.assert_nested("end_table");
+
+        let o = self.write_vtable(off)?;
+
+        self.nested = false;
+        self.field_locs.clear();
+
+        Ok(WIPOffset::new(o.value()))
+    }
+
     /// End a Table write.
     ///
     /// Asserts that the builder is in a nested state.
@@ -405,14 +452,19 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         &mut self,
         off: WIPOffset<TableUnfinishedWIPOffset>,
     ) -> WIPOffset<TableFinishedWIPOffset> {
-        self.assert_nested("end_table");
+        self.try_end_table(off)
+            .expect("Flatbuffer allocation failure")
+    }
 
-        let o = self.write_vtable(off);
-
-        self.nested = false;
-        self.field_locs.clear();
-
-        WIPOffset::new(o.value())
+    /// Fallible version of [`start_vector`](Self::start_vector).
+    #[inline]
+    pub fn try_start_vector<T: Push>(&mut self, num_items: usize) -> Result<(), A::Error> {
+        self.assert_not_nested(
+            "start_vector can not be called when a table or vector is under construction",
+        );
+        self.align(num_items * T::size(), T::alignment().max_of(SIZE_UOFFSET))?;
+        self.nested = true;
+        Ok(())
     }
 
     /// Start a Vector write.
@@ -424,11 +476,20 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     /// function will want to use `push` to add values.
     #[inline]
     pub fn start_vector<T: Push>(&mut self, num_items: usize) {
-        self.assert_not_nested(
-            "start_vector can not be called when a table or vector is under construction",
-        );
-        self.nested = true;
-        self.align(num_items * T::size(), T::alignment().max_of(SIZE_UOFFSET));
+        self.try_start_vector::<T>(num_items)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`end_vector`](Self::end_vector).
+    #[inline]
+    pub fn try_end_vector<T: Push>(
+        &mut self,
+        num_elems: usize,
+    ) -> Result<WIPOffset<Vector<'fbb, T>>, A::Error> {
+        self.assert_nested("end_vector");
+        let o = self.try_push::<UOffsetT>(num_elems as UOffsetT)?;
+        self.nested = false;
+        Ok(WIPOffset::new(o.value()))
     }
 
     /// End a Vector write.
@@ -439,10 +500,31 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     /// Asserts that the builder is in a nested state.
     #[inline]
     pub fn end_vector<T: Push>(&mut self, num_elems: usize) -> WIPOffset<Vector<'fbb, T>> {
-        self.assert_nested("end_vector");
-        self.nested = false;
-        let o = self.push::<UOffsetT>(num_elems as UOffsetT);
-        WIPOffset::new(o.value())
+        self.try_end_vector::<T>(num_elems)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`create_shared_string`](Self::create_shared_string).
+    ///
+    /// Uses a HashMap to track previously written strings, providing O(1)
+    /// amortized lookup and insertion.
+    #[cfg(feature = "std")]
+    #[inline]
+    pub fn try_create_shared_string<'a: 'b, 'b>(
+        &'a mut self,
+        s: &'b str,
+    ) -> Result<WIPOffset<&'fbb str>, A::Error> {
+        self.assert_not_nested(
+            "create_shared_string can not be called when a table or vector is under construction",
+        );
+
+        if let Some(&offset) = self.strings_pool.get(s) {
+            return Ok(offset);
+        }
+
+        let address = WIPOffset::new(self.try_create_byte_string(s.as_bytes())?.value());
+        self.strings_pool.insert(s.to_owned(), address);
+        Ok(address)
     }
 
     /// Create a utf8 string, and de-duplicate if already created.
@@ -452,26 +534,20 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     #[cfg(feature = "std")]
     #[inline]
     pub fn create_shared_string<'a: 'b, 'b>(&'a mut self, s: &'b str) -> WIPOffset<&'fbb str> {
-        self.assert_not_nested(
-            "create_shared_string can not be called when a table or vector is under construction",
-        );
-
-        if let Some(&offset) = self.strings_pool.get(s) {
-            return offset;
-        }
-
-        let address = WIPOffset::new(self.create_byte_string(s.as_bytes()).value());
-        self.strings_pool.insert(s.to_owned(), address);
-        address
+        self.try_create_shared_string(s)
+            .expect("Flatbuffer allocation failure")
     }
 
-    /// Create a utf8 string, and de-duplicate if already created.
+    /// Fallible version of [`create_shared_string`](Self::create_shared_string).
     ///
     /// Uses a sorted Vec with binary search to track previously written
     /// strings when in `no_std` mode.
     #[cfg(not(feature = "std"))]
     #[inline]
-    pub fn create_shared_string<'a: 'b, 'b>(&'a mut self, s: &'b str) -> WIPOffset<&'fbb str> {
+    pub fn try_create_shared_string<'a: 'b, 'b>(
+        &'a mut self,
+        s: &'b str,
+    ) -> Result<WIPOffset<&'fbb str>, A::Error> {
         self.assert_not_nested(
             "create_shared_string can not be called when a table or vector is under construction",
         );
@@ -494,52 +570,83 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         });
 
         match found {
-            Ok(index) => self.strings_pool[index],
+            Ok(index) => Ok(self.strings_pool[index]),
             Err(index) => {
-                let address = WIPOffset::new(self.create_byte_string(s.as_bytes()).value());
+                let address =
+                    WIPOffset::new(self.try_create_byte_string(s.as_bytes())?.value());
                 self.strings_pool.insert(index, address);
-                address
+                Ok(address)
             }
         }
     }
 
+    /// Create a utf8 string, and de-duplicate if already created.
+    ///
+    /// Uses a sorted Vec with binary search to track previously written
+    /// strings when in `no_std` mode.
+    #[cfg(not(feature = "std"))]
+    #[inline]
+    pub fn create_shared_string<'a: 'b, 'b>(&'a mut self, s: &'b str) -> WIPOffset<&'fbb str> {
+        self.try_create_shared_string(s)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`create_string`](Self::create_string).
+    #[inline]
+    pub fn try_create_string<'a: 'b, 'b>(
+        &'a mut self,
+        s: &'b str,
+    ) -> Result<WIPOffset<&'fbb str>, A::Error> {
+        self.assert_not_nested(
+            "create_string can not be called when a table or vector is under construction",
+        );
+        Ok(WIPOffset::new(
+            self.try_create_byte_string(s.as_bytes())?.value(),
+        ))
+    }
+
     /// Create a utf8 string.
     ///
     /// The wire format represents this as a zero-terminated byte vector.
     #[inline]
     pub fn create_string<'a: 'b, 'b>(&'a mut self, s: &'b str) -> WIPOffset<&'fbb str> {
+        self.try_create_string(s)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`create_byte_string`](Self::create_byte_string).
+    #[inline]
+    pub fn try_create_byte_string(
+        &mut self,
+        data: &[u8],
+    ) -> Result<WIPOffset<&'fbb [u8]>, A::Error> {
         self.assert_not_nested(
-            "create_string can not be called when a table or vector is under construction",
+            "create_byte_string can not be called when a table or vector is under construction",
         );
-        WIPOffset::new(self.create_byte_string(s.as_bytes()).value())
+        self.align(data.len() + 1, PushAlignment::new(SIZE_UOFFSET))?;
+        self.try_push(0u8)?;
+        self.push_bytes_unprefixed(data)?;
+        self.try_push(data.len() as UOffsetT)?;
+        Ok(WIPOffset::new(self.used_space() as UOffsetT))
     }
 
     /// Create a zero-terminated byte vector.
     #[inline]
     pub fn create_byte_string(&mut self, data: &[u8]) -> WIPOffset<&'fbb [u8]> {
-        self.assert_not_nested(
-            "create_byte_string can not be called when a table or vector is under construction",
-        );
-        self.align(data.len() + 1, PushAlignment::new(SIZE_UOFFSET));
-        self.push(0u8);
-        self.push_bytes_unprefixed(data);
-        self.push(data.len() as UOffsetT);
-        WIPOffset::new(self.used_space() as UOffsetT)
+        self.try_create_byte_string(data)
+            .expect("Flatbuffer allocation failure")
     }
 
-    /// Create a vector of Push-able objects.
-    ///
-    /// Speed-sensitive users may wish to reduce memory usage by creating the
-    /// vector manually: use `start_vector`, `push`, and `end_vector`.
+    /// Fallible version of [`create_vector`](Self::create_vector).
     #[inline]
-    pub fn create_vector<'a: 'b, 'b, T: Push + 'b>(
+    pub fn try_create_vector<'a: 'b, 'b, T: Push + 'b>(
         &'a mut self,
         items: &'b [T],
-    ) -> WIPOffset<Vector<'fbb, T::Output>> {
+    ) -> Result<WIPOffset<Vector<'fbb, T::Output>>, A::Error> {
         let elem_size = T::size();
         let slice_size = items.len() * elem_size;
-        self.align(slice_size, T::alignment().max_of(SIZE_UOFFSET));
-        self.ensure_capacity(slice_size + UOffsetT::size());
+        self.align(slice_size, T::alignment().max_of(SIZE_UOFFSET))?;
+        self.ensure_capacity(slice_size + UOffsetT::size())?;
 
         self.head -= slice_size;
         let mut written_len = self.head.distance_to_end();
@@ -553,7 +660,38 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
             unsafe { item.push(out, written_len) };
         }
 
-        WIPOffset::new(self.push::<UOffsetT>(items.len() as UOffsetT).value())
+        Ok(WIPOffset::new(
+            self.try_push::<UOffsetT>(items.len() as UOffsetT)?.value(),
+        ))
+    }
+
+    /// Create a vector of Push-able objects.
+    ///
+    /// Speed-sensitive users may wish to reduce memory usage by creating the
+    /// vector manually: use `start_vector`, `push`, and `end_vector`.
+    #[inline]
+    pub fn create_vector<'a: 'b, 'b, T: Push + 'b>(
+        &'a mut self,
+        items: &'b [T],
+    ) -> WIPOffset<Vector<'fbb, T::Output>> {
+        self.try_create_vector(items)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`create_vector_from_iter`](Self::create_vector_from_iter).
+    #[inline]
+    pub fn try_create_vector_from_iter<T: Push>(
+        &mut self,
+        items: impl ExactSizeIterator<Item = T> + DoubleEndedIterator,
+    ) -> Result<WIPOffset<Vector<'fbb, T::Output>>, A::Error> {
+        let elem_size = T::size();
+        self.align(items.len() * elem_size, T::alignment().max_of(SIZE_UOFFSET))?;
+        let mut actual = 0;
+        for item in items.rev() {
+            self.try_push(item)?;
+            actual += 1;
+        }
+        Ok(WIPOffset::new(self.try_push::<UOffsetT>(actual)?.value()))
     }
 
     /// Create a vector of Push-able objects.
@@ -565,14 +703,8 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         &mut self,
         items: impl ExactSizeIterator<Item = T> + DoubleEndedIterator,
     ) -> WIPOffset<Vector<'fbb, T::Output>> {
-        let elem_size = T::size();
-        self.align(items.len() * elem_size, T::alignment().max_of(SIZE_UOFFSET));
-        let mut actual = 0;
-        for item in items.rev() {
-            self.push(item);
-            actual += 1;
-        }
-        WIPOffset::new(self.push::<UOffsetT>(actual).value())
+        self.try_create_vector_from_iter(items)
+            .expect("Flatbuffer allocation failure")
     }
 
     /// Set whether default values are stored.
@@ -635,13 +767,34 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         assert!(o != 0, "missing required field {}", assert_msg_name);
     }
 
+    /// Fallible version of [`finish_size_prefixed`](Self::finish_size_prefixed).
+    #[inline]
+    pub fn try_finish_size_prefixed<T>(
+        &mut self,
+        root: WIPOffset<T>,
+        file_identifier: Option<&str>,
+    ) -> Result<(), A::Error> {
+        self.finish_with_opts(root, file_identifier, true)
+    }
+
     /// Finalize the FlatBuffer by: aligning it, pushing an optional file
     /// identifier on to it, pushing a size prefix on to it, and marking the
     /// internal state of the FlatBufferBuilder as `finished`. Afterwards,
     /// users can call `finished_data` to get the resulting data.
     #[inline]
     pub fn finish_size_prefixed<T>(&mut self, root: WIPOffset<T>, file_identifier: Option<&str>) {
-        self.finish_with_opts(root, file_identifier, true);
+        self.try_finish_size_prefixed(root, file_identifier)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`finish`](Self::finish).
+    #[inline]
+    pub fn try_finish<T>(
+        &mut self,
+        root: WIPOffset<T>,
+        file_identifier: Option<&str>,
+    ) -> Result<(), A::Error> {
+        self.finish_with_opts(root, file_identifier, false)
     }
 
     /// Finalize the FlatBuffer by: aligning it, pushing an optional file
@@ -650,7 +803,14 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     /// `finished_data` to get the resulting data.
     #[inline]
     pub fn finish<T>(&mut self, root: WIPOffset<T>, file_identifier: Option<&str>) {
-        self.finish_with_opts(root, file_identifier, false);
+        self.try_finish(root, file_identifier)
+            .expect("Flatbuffer allocation failure")
+    }
+
+    /// Fallible version of [`finish_minimal`](Self::finish_minimal).
+    #[inline]
+    pub fn try_finish_minimal<T>(&mut self, root: WIPOffset<T>) -> Result<(), A::Error> {
+        self.finish_with_opts(root, None, false)
     }
 
     /// Finalize the FlatBuffer by: aligning it and marking the internal state
@@ -658,7 +818,8 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     /// `finished_data` to get the resulting data.
     #[inline]
     pub fn finish_minimal<T>(&mut self, root: WIPOffset<T>) {
-        self.finish_with_opts(root, None, false);
+        self.try_finish_minimal(root)
+            .expect("Flatbuffer allocation failure")
     }
 
     #[inline]
@@ -676,13 +837,13 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     fn write_vtable(
         &mut self,
         table_tail_revloc: WIPOffset<TableUnfinishedWIPOffset>,
-    ) -> WIPOffset<VTableWIPOffset> {
+    ) -> Result<WIPOffset<VTableWIPOffset>, A::Error> {
         self.assert_nested("write_vtable");
 
         // Write the vtable offset, which is the start of any Table.
         // We fill its value later.
         let object_revloc_to_vtable: WIPOffset<VTableWIPOffset> =
-            WIPOffset::new(self.push::<UOffsetT>(0xF0F0_F0F0).value());
+            WIPOffset::new(self.try_push::<UOffsetT>(0xF0F0_F0F0)?.value());
 
         // Layout of the data this function will create when a new vtable is
         // needed.
@@ -725,7 +886,7 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
 
         // fill the WIP vtable with zeros:
         let vtable_byte_len = get_vtable_byte_len(&self.field_locs);
-        self.make_space(vtable_byte_len);
+        self.make_space(vtable_byte_len)?;
 
         // compute the length of the table (not vtable!) in bytes:
         let table_object_size = object_revloc_to_vtable.value() - table_tail_revloc.value();
@@ -750,13 +911,15 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
             }
         }
         let new_vt_bytes = &self.allocator[vt_start_pos.range_to(vt_end_pos)];
-        let found = self.written_vtable_revpos.binary_search_by(|old_vtable_revpos: &UOffsetT| {
-            let old_vtable_pos = self.allocator.len() - *old_vtable_revpos as usize;
-            // Safety:
-            // Already written vtables are valid by construction
-            let old_vtable = unsafe { VTable::init(&self.allocator, old_vtable_pos) };
-            new_vt_bytes.cmp(old_vtable.as_bytes())
-        });
+        let found = self
+            .written_vtable_revpos
+            .binary_search_by(|old_vtable_revpos: &UOffsetT| {
+                let old_vtable_pos = self.allocator.len() - *old_vtable_revpos as usize;
+                // Safety:
+                // Already written vtables are valid by construction
+                let old_vtable = unsafe { VTable::init(&self.allocator, old_vtable_pos) };
+                new_vt_bytes.cmp(old_vtable.as_bytes())
+            });
         let final_vtable_revpos = match found {
             Ok(i) => {
                 // The new vtable is a duplicate so clear it.
@@ -794,17 +957,18 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
 
         self.field_locs.clear();
 
-        object_revloc_to_vtable
+        Ok(object_revloc_to_vtable)
     }
 
     // Only call this when you know it is safe to double the size of the buffer.
     #[inline]
-    fn grow_allocator(&mut self) {
+    fn grow_allocator(&mut self) -> Result<(), A::Error> {
         let starting_active_size = self.used_space();
-        self.allocator.grow_downwards().expect("Flatbuffer allocation failure");
+        self.allocator.grow_downwards()?;
 
         let ending_active_size = self.used_space();
         debug_assert_eq!(starting_active_size, ending_active_size);
+        Ok(())
     }
 
     // with or without a size prefix changes how we load the data, so finish*
@@ -814,7 +978,7 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
         root: WIPOffset<T>,
         file_identifier: Option<&str>,
         size_prefixed: bool,
-    ) {
+    ) -> Result<(), A::Error> {
         self.assert_not_finished("buffer cannot be finished when it is already finished");
         self.assert_not_nested(
             "buffer cannot be finished when a table or vector is under construction",
@@ -827,34 +991,40 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
             // for the size prefix:
             let b = if size_prefixed { SIZE_UOFFSET } else { 0 };
             // for the file identifier (a string that is not zero-terminated):
-            let c = if file_identifier.is_some() { FILE_IDENTIFIER_LENGTH } else { 0 };
+            let c = if file_identifier.is_some() {
+                FILE_IDENTIFIER_LENGTH
+            } else {
+                0
+            };
             a + b + c
         };
 
         {
             let ma = PushAlignment::new(self.min_align);
-            self.align(to_align, ma);
+            self.align(to_align, ma)?;
         }
 
         if let Some(ident) = file_identifier {
             debug_assert_eq!(ident.len(), FILE_IDENTIFIER_LENGTH);
-            self.push_bytes_unprefixed(ident.as_bytes());
+            self.push_bytes_unprefixed(ident.as_bytes())?;
         }
 
-        self.push(root);
+        self.try_push(root)?;
 
         if size_prefixed {
             let sz = self.used_space() as UOffsetT;
-            self.push::<UOffsetT>(sz);
+            self.try_push::<UOffsetT>(sz)?;
         }
         self.finished = true;
+        Ok(())
     }
 
     #[inline]
-    fn align(&mut self, len: usize, alignment: PushAlignment) {
+    fn align(&mut self, len: usize, alignment: PushAlignment) -> Result<(), A::Error> {
         self.track_min_align(alignment.value());
         let s = self.used_space() as usize;
-        self.make_space(padding_bytes(s + len, alignment.value()));
+        self.make_space(padding_bytes(s + len, alignment.value()))?;
+        Ok(())
     }
 
     #[inline]
@@ -863,31 +1033,34 @@ impl<'fbb, A: Allocator> FlatBufferBuilder<'fbb, A> {
     }
 
     #[inline]
-    fn push_bytes_unprefixed(&mut self, x: &[u8]) -> UOffsetT {
-        let n = self.make_space(x.len());
+    fn push_bytes_unprefixed(&mut self, x: &[u8]) -> Result<UOffsetT, A::Error> {
+        let n = self.make_space(x.len())?;
         self.allocator[n.range_to(n + x.len())].copy_from_slice(x);
 
-        n.to_forward_index(&self.allocator) as UOffsetT
+        Ok(n.to_forward_index(&self.allocator) as UOffsetT)
     }
 
     #[inline]
-    fn make_space(&mut self, want: usize) -> ReverseIndex {
-        self.ensure_capacity(want);
+    fn make_space(&mut self, want: usize) -> Result<ReverseIndex, A::Error> {
+        self.ensure_capacity(want)?;
         self.head -= want;
-        self.head
+        Ok(self.head)
     }
 
     #[inline]
-    fn ensure_capacity(&mut self, want: usize) -> usize {
+    fn ensure_capacity(&mut self, want: usize) -> Result<usize, A::Error> {
         if self.unused_ready_space() >= want {
-            return want;
+            return Ok(want);
         }
-        assert!(want <= FLATBUFFERS_MAX_BUFFER_SIZE, "cannot grow buffer beyond 2 gigabytes");
+        assert!(
+            want <= FLATBUFFERS_MAX_BUFFER_SIZE,
+            "cannot grow buffer beyond 2 gigabytes"
+        );
 
         while self.unused_ready_space() < want {
-            self.grow_allocator();
+            self.grow_allocator()?;
         }
-        want
+        Ok(want)
     }
     #[inline]
     fn unused_ready_space(&self) -> usize {
@@ -1129,4 +1302,111 @@ mod tests {
             allocs
         );
     }
+
+    /// A test allocator that fails after a specified number of grow operations.
+    struct FailingAllocator {
+        inner: DefaultAllocator,
+        grows_remaining: usize,
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq)]
+    struct AllocationError;
+
+    impl core::fmt::Display for AllocationError {
+        fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+            write!(f, "allocation failed")
+        }
+    }
+
+    impl FailingAllocator {
+        fn new(initial_size: usize, max_grows: usize) -> Self {
+            Self {
+                inner: DefaultAllocator::from_vec(vec![0u8; initial_size]),
+                grows_remaining: max_grows,
+            }
+        }
+    }
+
+    impl Deref for FailingAllocator {
+        type Target = [u8];
+        fn deref(&self) -> &Self::Target {
+            &self.inner
+        }
+    }
+
+    impl DerefMut for FailingAllocator {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.inner
+        }
+    }
+
+    unsafe impl Allocator for FailingAllocator {
+        type Error = AllocationError;
+
+        fn grow_downwards(&mut self) -> Result<(), Self::Error> {
+            if self.grows_remaining == 0 {
+                return Err(AllocationError);
+            }
+            self.grows_remaining -= 1;
+            // DefaultAllocator returns Infallible, so unwrap is safe
+            self.inner.grow_downwards().unwrap();
+            Ok(())
+        }
+
+        fn len(&self) -> usize {
+            self.inner.len()
+        }
+    }
+
+    #[test]
+    fn try_push_propagates_allocation_error() {
+        let allocator = FailingAllocator::new(1, 0);
+        let mut builder = FlatBufferBuilder::new_in(allocator);
+
+        let result = builder.try_push::<u64>(0x1234567890ABCDEF);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn try_create_string_propagates_allocation_error() {
+        let allocator = FailingAllocator::new(1, 0);
+        let mut builder = FlatBufferBuilder::new_in(allocator);
+
+        let result = builder.try_create_string("hello world");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn try_create_vector_propagates_allocation_error() {
+        let allocator = FailingAllocator::new(1, 0);
+        let mut builder = FlatBufferBuilder::new_in(allocator);
+
+        let result = builder.try_create_vector(&[1u32, 2, 3, 4, 5]);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn try_methods_succeed_with_sufficient_capacity() {
+        let allocator = FailingAllocator::new(1, 10);
+        let mut builder = FlatBufferBuilder::new_in(allocator);
+
+        let result = builder.try_create_string("hello");
+        assert!(result.is_ok());
+
+        let result = builder.try_create_vector(&[1u32, 2, 3]);
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn try_finish_propagates_allocation_error() {
+        let allocator = FailingAllocator::new(1, 3);
+        let mut builder = FlatBufferBuilder::new_in(allocator);
+
+        let start = builder.start_table();
+        let table = builder
+            .try_end_table(start)
+            .expect("end_table should succeed with 3 grows");
+        let result = builder.try_finish_minimal(table);
+        assert!(result.is_err(), "finish should fail after grows exhausted");
+    }
 }

rust/flatbuffers/src/verifier.rs

@@ -492,8 +492,8 @@ impl<'ver, 'opts, 'buf> TableVerifier<'ver, 'opts, 'buf> {
                 Ok(self)
             }
             _ => InvalidFlatbuffer::new_inconsistent_union(
-                key_field_name.into(),
                 val_field_name.into(),
+                key_field_name.into(),
             ),
         }
     }

rust/reflection/src/reflection_verifier.rs

@@ -397,8 +397,8 @@ fn verify_union<'a, 'b, 'c>(
         }
     } else {
         return InvalidFlatbuffer::new_inconsistent_union(
-            format!("{}_type", field.name()),
             field.name().to_string(),
+            format!("{}_type", field.name()),
         )?;
     }
 

scripts/generate_code.py

@@ -422,6 +422,11 @@ flatc(
     schema="nested_union_test.fbs",
 )
 
+flatc(
+    ["--python", "--gen-object-api"],
+    schema="union_name_test.fbs",
+)
+
 flatc(
     NO_INCL_OPTS + CPP_OPTS,
     schema="default_vectors_strings_test.fbs",

src/binary_annotator.cpp

@@ -126,9 +126,7 @@ static BinarySection GenerateMissingSection(const uint64_t offset,
 std::map<uint64_t, BinarySection> BinaryAnnotator::Annotate() {
   if (bfbs_ != nullptr && bfbs_length_ != 0) {
     flatbuffers::Verifier verifier(bfbs_, static_cast<size_t>(bfbs_length_));
-    if ((is_size_prefixed_ &&
-         !reflection::VerifySizePrefixedSchemaBuffer(verifier)) ||
-        !reflection::VerifySchemaBuffer(verifier)) {
+    if (!reflection::VerifySchemaBuffer(verifier)) {
       return {};
     }
   }

src/idl_gen_cpp.cpp

@@ -2779,15 +2779,17 @@ class CppGenerator : public BaseGenerator {
         get_call += ">(" + offset_str + ");";
         code_ += get_call;
       } else if (IsString(type) && field.value.constant != "0") {
-        // TODO: Add logic to always convert the string to a valid C++ string
-        // literal by handling string escapes.
+        std::string escaped;
+        flatbuffers::EscapeString(field.value.constant.c_str(),
+                                  field.value.constant.length(), &escaped,
+                                  true, false);
         code_ += "    auto* ptr = {{FIELD_VALUE}};";
         code_ += "    if (ptr) return ptr;";
         code_ += "    static const struct { uint32_t len; const char s[" +
                  NumToString(field.value.constant.length() + 1) +
                  "]; } bfbs_string = { " +
-                 NumToString(field.value.constant.length()) + ", \"" +
-                 field.value.constant + "\" };";
+                 NumToString(field.value.constant.length()) + ", " +
+                 escaped + " };";
         code_ +=
             "    return reinterpret_cast<const ::flatbuffers::String "
             " *>(&bfbs_string);";
@@ -3417,11 +3419,15 @@ class CppGenerator : public BaseGenerator {
             code_.SetValue("CREATE_STRING", "CreateSharedString");
           }
           if (field->value.constant != "0") {
+            std::string escaped;
+            flatbuffers::EscapeString(field->value.constant.c_str(),
+                                      field->value.constant.length(), &escaped,
+                                      true, false);
             code_ +=
                 "  auto {{FIELD_NAME}}__ = {{FIELD_NAME}} ? "
                 "_fbb.{{CREATE_STRING}}({{FIELD_NAME}}) : "
-                "_fbb.{{CREATE_STRING}}(\"" +
-                field->value.constant + "\");";
+                "_fbb.{{CREATE_STRING}}(" +
+                escaped + ");";
           } else {
             code_ +=
                 "  auto {{FIELD_NAME}}__ = {{FIELD_NAME}} ? "

src/idl_gen_fbs.cpp

@@ -368,7 +368,17 @@ static std::string GenerateFBS(const Parser& parser,
       if (field.value.type.base_type != BASE_TYPE_UTYPE) {
         GenComment(field.doc_comment, &schema, nullptr, "  ");
         schema += "  " + field.name + ":" + GenType(field.value.type);
-        if (field.value.constant != "0") schema += " = " + field.value.constant;
+        if (field.value.constant != "0") {
+          if (IsString(field.value.type)) {
+            std::string escaped;
+            flatbuffers::EscapeString(field.value.constant.c_str(),
+                                      field.value.constant.length(), &escaped,
+                                      true, false);
+            schema += " = " + escaped;
+          } else {
+            schema += " = " + field.value.constant;
+          }
+        }
         std::vector<std::string> attributes;
         if (field.IsRequired()) attributes.push_back("required");
         if (field.key) attributes.push_back("key");

src/idl_gen_python.cpp

@@ -2095,12 +2095,12 @@ class PythonGenerator : public BaseGenerator {
     const auto field_method = namer_.Method(field);
     const auto struct_var = namer_.Variable(struct_def);
     const EnumDef& enum_def = *field.value.type.enum_def;
-    auto union_type = namer_.Type(enum_def);
+    auto union_fn = namer_.Function(enum_def);
 
     if (parser_.opts.include_dependence_headers) {
-      union_type = namer_.NamespacedType(enum_def) + "." + union_type;
+      union_fn = namer_.NamespacedType(enum_def) + "." + union_fn;
     }
-    code += GenIndents(2) + "self." + field_field + " = " + union_type +
+    code += GenIndents(2) + "self." + field_field + " = " + union_fn +
             "Creator(" + "self." + field_field + "Type, " + struct_var + "." +
             field_method + "())";
   }

src/idl_gen_rust.cpp

@@ -1138,9 +1138,14 @@ class RustGenerator : public BaseGenerator {
         // need one for Rust's Default trait so we use empty string. The usual
         // value of field.value.constant is `0`, which is non-sensical except
         // maybe to c++ (nullptr == 0).
-        // TODO: Escape strings?
-        const std::string defval =
-            field.IsRequired() ? "\"\"" : "\"" + field.value.constant + "\"";
+        std::string defval;
+        if (field.IsRequired()) {
+          defval = "\"\"";
+        } else {
+          flatbuffers::EscapeString(field.value.constant.c_str(),
+                                    field.value.constant.length(), &defval,
+                                    true, false);
+        }
         if (context == kObject) {
           return "alloc::string::ToString::to_string(" + defval + ")";
         }

src/idl_gen_swift.cpp

@@ -859,7 +859,10 @@ class SwiftGenerator : public BaseGenerator {
         break;
 
       case BASE_TYPE_STRING: {
-        const auto default_string = "\"" + SwiftConstant(field) + "\"";
+        const auto sc = SwiftConstant(field);
+        std::string default_string;
+        flatbuffers::EscapeString(sc.c_str(), sc.length(), &default_string,
+                                  true, false);
         code_.SetValue("VALUETYPE", GenType(field.value.type));
         code_.SetValue("CONSTANT", field.IsDefault() ? default_string : "nil");
         code_ += GenReaderMainBody(is_required) + GenOffset() +
@@ -1649,15 +1652,23 @@ class SwiftGenerator : public BaseGenerator {
         buffer_constructor.push_back(field_var + " = _t." + field_field);
 
         if (field.IsRequired()) {
-          std::string default_value =
-              field.IsDefault() ? SwiftConstant(field) : "";
-          base_constructor.push_back(field_var + " = \"" + default_value +
-                                     "\"");
+          std::string default_value;
+          if (field.IsDefault()) {
+            const auto sc = SwiftConstant(field);
+            flatbuffers::EscapeString(sc.c_str(), sc.length(), &default_value,
+                                      true, false);
+          } else {
+            default_value = "\"\"";
+          }
+          base_constructor.push_back(field_var + " = " + default_value);
           break;
         }
         if (field.IsDefault() && !field.IsRequired()) {
-          std::string value = field.IsDefault() ? SwiftConstant(field) : "nil";
-          base_constructor.push_back(field_var + " = \"" + value + "\"");
+          const auto sc = SwiftConstant(field);
+          std::string value;
+          flatbuffers::EscapeString(sc.c_str(), sc.length(), &value,
+                                    true, false);
+          base_constructor.push_back(field_var + " = " + value);
         }
         break;
       }

src/idl_gen_ts.cpp

@@ -529,7 +529,11 @@ class TsGenerator : public BaseGenerator {
         if (value.constant == "0" || value.constant == "null") {
           return "null";
         } else {
-          return "\"" + value.constant + "\"";
+          std::string escaped;
+          flatbuffers::EscapeString(value.constant.c_str(),
+                                    value.constant.length(), &escaped,
+                                    true, false);
+          return escaped;
         }
       }
       case BASE_TYPE_UNION:

src/idl_parser.cpp

@@ -4132,7 +4132,15 @@ bool StructDef::Deserialize(Parser& parser, const reflection::Object* object) {
   sortbysize = attributes.Lookup("original_order") == nullptr && !fixed;
   const auto& of = *(object->fields());
   auto indexes = std::vector<uoffset_t>(of.size());
-  for (uoffset_t i = 0; i < of.size(); i++) indexes[of.Get(i)->id()] = i;
+  for (uoffset_t i = 0; i < of.size(); i++) {
+  uint16_t field_id = of.Get(i)->id();
+  if (field_id >= of.size()) {
+    parser.error_ = "Field ID " + std::to_string(field_id) + 
+                    " exceeds field count " + std::to_string(of.size());
+    return false;
+  }
+  indexes[field_id] = i;
+}
   size_t tmp_struct_size = 0;
   for (size_t i = 0; i < indexes.size(); i++) {
     auto field = of.Get(indexes[i]);

src/reflection.cpp

@@ -389,7 +389,7 @@ void ForAllFields(const reflection::Object* object, bool reverse,
 
   for (size_t i = 0; i < field_to_id_map.size(); ++i) {
     func(object->fields()->Get(
-        field_to_id_map[reverse ? field_to_id_map.size() - i + 1 : i]));
+        field_to_id_map[reverse ? field_to_id_map.size() - (i + 1) : i]));
   }
 }
 
@@ -641,7 +641,10 @@ const uint8_t* AddFlatBuffer(std::vector<uint8_t>& flatbuf,
                              const uint8_t* newbuf, size_t newlen) {
   // Align to sizeof(uoffset_t) past sizeof(largest_scalar_t) since we're
   // going to chop off the root offset.
+  if (!newbuf || newlen < sizeof(uoffset_t)) return nullptr;
   FLATBUFFERS_ASSERT(newlen >= sizeof(uoffset_t));
+  auto root = ReadScalar<uoffset_t>(newbuf);
+  if (root < sizeof(uoffset_t) || root >= newlen) return nullptr;
   while ((flatbuf.size() & (sizeof(uoffset_t) - 1)) ||
          !(flatbuf.size() & (sizeof(largest_scalar_t) - 1))) {
     flatbuf.push_back(0);
@@ -649,7 +652,7 @@ const uint8_t* AddFlatBuffer(std::vector<uint8_t>& flatbuf,
   auto insertion_point = static_cast<uoffset_t>(flatbuf.size());
   // Insert the entire FlatBuffer minus the root pointer.
   flatbuf.insert(flatbuf.end(), newbuf + sizeof(uoffset_t), newbuf + newlen);
-  auto root_offset = ReadScalar<uoffset_t>(newbuf) - sizeof(uoffset_t);
+  auto root_offset = root - sizeof(uoffset_t);
   return flatbuf.data() + insertion_point + root_offset;
 }
 

tests/PythonTest.sh

@@ -28,6 +28,7 @@ ${test_dir}/../flatc -p -o ${gen_code_path} -I include_test monster_extra.fbs --
 ${test_dir}/../flatc -p -o ${gen_code_path} -I include_test arrays_test.fbs --gen-object-api --python-typing
 ${test_dir}/../flatc -p -o ${gen_code_path} -I include_test nested_union_test.fbs --gen-object-api --python-typing --python-decode-obj-api-strings
 ${test_dir}/../flatc -p -o ${gen_code_path} -I include_test service_test.fbs --grpc --grpc-python-typed-handlers --python-typing --no-python-gen-numpy --gen-onefile
+${test_dir}/../flatc -p -o ${gen_code_path} union_name_test.fbs --gen-object-api
 
 # Syntax: run_tests <interpreter> <benchmark vtable dedupes>
 #                   <benchmark read count> <benchmark build count>

tests/flexbuffers_test.cpp

@@ -1,5 +1,6 @@
 #include "flexbuffers_test.h"
 
+#include <memory>
 #include <limits>
 
 #include "flatbuffers/flexbuffers.h"
@@ -13,6 +14,13 @@ namespace tests {
 // Shortcuts for the infinity.
 static const auto infinity_d = std::numeric_limits<double>::infinity();
 
+static bool IsAligned(const void* ptr, std::size_t alignment) {
+  void* p = const_cast<void*>(ptr);
+  std::size_t space = 2 * alignment;
+  void* q = std::align(alignment, alignment, p, space);
+  return q != nullptr && p == ptr && space == 2 * alignment;
+}
+
 void FlexBuffersTest() {
   flexbuffers::Builder slb(512,
                            flexbuffers::BUILDER_FLAG_SHARE_KEYS_AND_STRINGS);
@@ -29,7 +37,10 @@ void FlexBuffersTest() {
       slb.IndirectFloat(4.0f);
       auto i_f = slb.LastValue();
       uint8_t blob[] = {77};
-      slb.Blob(blob, 1);
+      uint32_t aligned_blob[] = {88, 99};
+      slb.Blob(blob, sizeof blob);
+      slb.AlignedBlob(aligned_blob, sizeof aligned_blob,
+                      flexbuffers::BIT_WIDTH_32);
       slb += false;
       slb.ReuseValue(i_f);
     });
@@ -62,7 +73,7 @@ void FlexBuffersTest() {
   auto map = flexbuffers::GetRoot(slb.GetBuffer()).AsMap();
   TEST_EQ(map.size(), 7);
   auto vec = map["vec"].AsVector();
-  TEST_EQ(vec.size(), 6);
+  TEST_EQ(vec.size(), 7);
   TEST_EQ(vec[0].AsInt64(), -100);
   TEST_EQ_STR(vec[1].AsString().c_str(), "Fred");
   TEST_EQ(vec[1].AsInt64(), 0);  // Number parsing failed.
@@ -80,9 +91,15 @@ void FlexBuffersTest() {
   auto blob = vec[3].AsBlob();
   TEST_EQ(blob.size(), 1);
   TEST_EQ(blob.data()[0], 77);
-  TEST_EQ(vec[4].IsBool(), true);   // Check if type is a bool
-  TEST_EQ(vec[4].AsBool(), false);  // Check if value is false
-  TEST_EQ(vec[5].AsDouble(), 4.0);  // This is shared with vec[2] !
+  TEST_EQ(vec[4].IsBlob(), true);
+  auto aligned_blob = vec[4].AsBlob();
+  TEST_EQ(aligned_blob.size(), 8);
+  TEST_EQ(reinterpret_cast<const uint32_t*>(aligned_blob.data())[0], 88);
+  TEST_EQ(reinterpret_cast<const uint32_t*>(aligned_blob.data())[1], 99);
+  TEST_EQ(IsAligned(aligned_blob.data(), 4), true);
+  TEST_EQ(vec[5].IsBool(), true);   // Check if type is a bool
+  TEST_EQ(vec[5].AsBool(), false);  // Check if value is false
+  TEST_EQ(vec[6].AsDouble(), 4.0);  // This is shared with vec[2] !
   auto tvec = map["bar"].AsTypedVector();
   TEST_EQ(tvec.size(), 3);
   TEST_EQ(tvec[2].AsInt8(), 3);
@@ -107,9 +124,9 @@ void FlexBuffersTest() {
   TEST_EQ(vec[2].MutateFloat(2.0f), true);
   TEST_EQ(vec[2].AsFloat(), 2.0f);
   TEST_EQ(vec[2].MutateFloat(3.14159), false);  // Double does not fit in float.
-  TEST_EQ(vec[4].AsBool(), false);              // Is false before change
-  TEST_EQ(vec[4].MutateBool(true), true);       // Can change a bool
-  TEST_EQ(vec[4].AsBool(), true);               // Changed bool is now true
+  TEST_EQ(vec[5].AsBool(), false);              // Is false before change
+  TEST_EQ(vec[5].MutateBool(true), true);       // Can change a bool
+  TEST_EQ(vec[5].AsBool(), true);               // Changed bool is now true
 
   // Parse from JSON:
   flatbuffers::Parser parser;

tests/py_test.py

@@ -55,6 +55,10 @@ import MyGame.Example.NestedUnion.Color  # refers to generated code
 import monster_test_generated  # the one-file version
 import optional_scalars
 import optional_scalars.ScalarStuff
+import union_name_test.Container  # refers to generated code
+import union_name_test.Foo  # refers to generated code
+import union_name_test.Bar  # refers to generated code
+import union_name_test.my_test_union  # refers to generated code
 
 
 def create_namespace_shortcut(is_onefile):
@@ -3020,6 +3024,50 @@ class TestNestedUnionTables(unittest.TestCase):
     )
 
 
+class TestUnionCreatorNaming(unittest.TestCase):
+  """Tests that union creator functions use consistent naming (issue #8843).
+
+  Uses a schema with a snake_case union name (my_test_union) to verify that
+  the generated creator function name matches between definition and call site.
+  """
+
+  def test_union_creator_pack_unpack(self):
+    """Pack and UnPack a table with a non-UpperCamel union name."""
+    containerT = union_name_test.Container.ContainerT()
+    containerT.uType = union_name_test.my_test_union.my_test_union.Foo
+    containerT.u = union_name_test.Foo.FooT()
+    containerT.u.val = 42
+
+    b = flatbuffers.Builder(0)
+    b.Finish(containerT.Pack(b))
+
+    container = union_name_test.Container.Container.GetRootAs(
+        b.Bytes, b.Head()
+    )
+    containerT2 = union_name_test.Container.ContainerT.InitFromObj(container)
+
+    self.assertEqual(containerT2.uType, union_name_test.my_test_union.my_test_union.Foo)
+    self.assertEqual(containerT2.u.val, 42)
+
+  def test_union_creator_with_bar(self):
+    """Test the other union variant to ensure all branches work."""
+    containerT = union_name_test.Container.ContainerT()
+    containerT.uType = union_name_test.my_test_union.my_test_union.Bar
+    containerT.u = union_name_test.Bar.BarT()
+    containerT.u.name = "hello"
+
+    b = flatbuffers.Builder(0)
+    b.Finish(containerT.Pack(b))
+
+    container = union_name_test.Container.Container.GetRootAs(
+        b.Bytes, b.Head()
+    )
+    containerT2 = union_name_test.Container.ContainerT.InitFromObj(container)
+
+    self.assertEqual(containerT2.uType, union_name_test.my_test_union.my_test_union.Bar)
+    self.assertEqual(containerT2.u.name, b"hello")
+
+
 class TestBuilderClear(unittest.TestCase):
 
   def test_consistency(self):

tests/reflection_test.cpp

@@ -248,6 +248,93 @@ void ReflectionTest(const std::string& tests_data_path, uint8_t* flatbuf,
           true);
 }
 
+// Test that ForAllFields with reverse=true iterates fields in descending
+// ID order. This exercises a fix for an operator precedence bug where the
+// expression `size() - i + 1` was evaluated as `(size() - i) + 1` instead
+// of the correct `size() - (i + 1)`, causing an out-of-bounds read.
+void ForAllFieldsReverseTest(const std::string& tests_data_path) {
+  // Load the binary schema.
+  std::string bfbsfile;
+  TEST_EQ(flatbuffers::LoadFile((tests_data_path + "monster_test.bfbs").c_str(),
+                                true, &bfbsfile),
+          true);
+
+  // Verify the schema.
+  flatbuffers::Verifier verifier(
+      reinterpret_cast<const uint8_t*>(bfbsfile.c_str()), bfbsfile.length());
+  TEST_EQ(reflection::VerifySchemaBuffer(verifier), true);
+
+  auto& schema = *reflection::GetSchema(bfbsfile.c_str());
+
+  // Use the Stat table which has 3 fields with sequential IDs:
+  //   id:string   (id: 0)
+  //   val:long     (id: 1)
+  //   count:ushort (id: 2)
+  auto stat_object = schema.objects()->LookupByKey("MyGame.Example.Stat");
+  TEST_NOTNULL(stat_object);
+  TEST_EQ(stat_object->fields()->size(), 3u);
+
+  // Test forward iteration: fields should come in ascending ID order (0,1,2).
+  {
+    std::vector<uint16_t> forward_ids;
+    flatbuffers::ForAllFields(
+        stat_object, /*reverse=*/false,
+        [&forward_ids](const reflection::Field* field) {
+          forward_ids.push_back(field->id());
+        });
+    TEST_EQ(forward_ids.size(), 3u);
+    TEST_EQ(forward_ids[0], 0);  // id
+    TEST_EQ(forward_ids[1], 1);  // val
+    TEST_EQ(forward_ids[2], 2);  // count
+  }
+
+  // Test reverse iteration: fields should come in descending ID order (2,1,0).
+  // With the old buggy code `size() - i + 1`, at i=0 this would compute
+  // index 3 - 0 + 1 = 4, which is out of bounds for a size-3 vector.
+  {
+    std::vector<uint16_t> reverse_ids;
+    flatbuffers::ForAllFields(
+        stat_object, /*reverse=*/true,
+        [&reverse_ids](const reflection::Field* field) {
+          reverse_ids.push_back(field->id());
+        });
+    TEST_EQ(reverse_ids.size(), 3u);
+    TEST_EQ(reverse_ids[0], 2);  // count (highest ID first)
+    TEST_EQ(reverse_ids[1], 1);  // val
+    TEST_EQ(reverse_ids[2], 0);  // id (lowest ID last)
+  }
+
+  // Also test with the root Monster table which has many fields and
+  // non-sequential definition order vs. ID order (e.g., pos=id:0, hp=id:2,
+  // mana=id:1). This ensures the ID-to-index mapping works correctly.
+  auto root_table = schema.root_table();
+  TEST_NOTNULL(root_table);
+  {
+    std::vector<uint16_t> forward_ids;
+    flatbuffers::ForAllFields(
+        root_table, /*reverse=*/false,
+        [&forward_ids](const reflection::Field* field) {
+          forward_ids.push_back(field->id());
+        });
+    // Verify ascending order.
+    for (size_t i = 1; i < forward_ids.size(); ++i) {
+      TEST_ASSERT(forward_ids[i - 1] < forward_ids[i]);
+    }
+  }
+  {
+    std::vector<uint16_t> reverse_ids;
+    flatbuffers::ForAllFields(
+        root_table, /*reverse=*/true,
+        [&reverse_ids](const reflection::Field* field) {
+          reverse_ids.push_back(field->id());
+        });
+    // Verify descending order.
+    for (size_t i = 1; i < reverse_ids.size(); ++i) {
+      TEST_ASSERT(reverse_ids[i - 1] > reverse_ids[i]);
+    }
+  }
+}
+
 void MiniReflectFlatBuffersTest(uint8_t* flatbuf) {
   auto s =
       flatbuffers::FlatBufferToString(flatbuf, Monster::MiniReflectTypeTable());

tests/reflection_test.h

@@ -10,6 +10,7 @@ namespace tests {
 
 void ReflectionTest(const std::string& tests_data_path, uint8_t* flatbuf,
                     size_t length);
+void ForAllFieldsReverseTest(const std::string& tests_data_path);
 void MiniReflectFixedLengthArrayTest();
 void MiniReflectFlatBuffersTest(uint8_t* flatbuf);
 

tests/rust_usage_test/tests/integration_test.rs

@@ -3448,4 +3448,250 @@ fn test_shared_strings_pool_deduplication() {
 }
 
 } // mod flatbuffers_tests
+
+#[cfg(test)]
+mod try_api {
+    extern crate flatbuffers;
+
+    use alloc::vec::Vec;
+    use flatbuffers::Follow;
+    use super::my_game;
+    use super::serialized_example_is_accessible_and_correct;
+
+    #[test]
+    fn try_api_full_table_roundtrip() {
+        // Build a Monster using exclusively try_* API (mirrors library_code example).
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+
+        let nested_union_mon = {
+            let name = builder.try_create_string("Fred").unwrap();
+            let table_start = builder.start_table();
+            builder
+                .try_push_slot_always(my_game::example::Monster::VT_NAME, name)
+                .unwrap();
+            builder.try_end_table(table_start).unwrap()
+        };
+        let pos = my_game::example::Vec3::new(
+            1.0,
+            2.0,
+            3.0,
+            3.0,
+            my_game::example::Color::Green,
+            &my_game::example::Test::new(5i16, 6i8),
+        );
+        let inv = builder.try_create_vector(&[0u8, 1, 2, 3, 4]).unwrap();
+        let test4 = builder
+            .try_create_vector(
+                &[
+                    my_game::example::Test::new(10, 20),
+                    my_game::example::Test::new(30, 40),
+                ][..],
+            )
+            .unwrap();
+
+        let name = builder.try_create_string("MyMonster").unwrap();
+        let test1 = builder.try_create_string("test1").unwrap();
+        let test2 = builder.try_create_string("test2").unwrap();
+        let testarrayofstring = builder.try_create_vector(&[test1, test2]).unwrap();
+
+        let table_start = builder.start_table();
+        builder
+            .try_push_slot(my_game::example::Monster::VT_HP, 80i16, 100)
+            .unwrap();
+        builder
+            .try_push_slot_always(my_game::example::Monster::VT_NAME, name)
+            .unwrap();
+        builder
+            .try_push_slot_always(my_game::example::Monster::VT_POS, &pos)
+            .unwrap();
+        builder
+            .try_push_slot(
+                my_game::example::Monster::VT_TEST_TYPE,
+                my_game::example::Any::Monster,
+                my_game::example::Any::NONE,
+            )
+            .unwrap();
+        builder
+            .try_push_slot_always(my_game::example::Monster::VT_TEST, nested_union_mon)
+            .unwrap();
+        builder
+            .try_push_slot_always(my_game::example::Monster::VT_INVENTORY, inv)
+            .unwrap();
+        builder
+            .try_push_slot_always(my_game::example::Monster::VT_TEST4, test4)
+            .unwrap();
+        builder
+            .try_push_slot_always(
+                my_game::example::Monster::VT_TESTARRAYOFSTRING,
+                testarrayofstring,
+            )
+            .unwrap();
+        let root = builder.try_end_table(table_start).unwrap();
+        builder
+            .try_finish(root, Some(my_game::example::MONSTER_IDENTIFIER))
+            .unwrap();
+
+        let buf = builder.finished_data();
+        serialized_example_is_accessible_and_correct(buf, true, false).unwrap();
+    }
+
+    #[test]
+    fn try_shared_string_deduplication() {
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let offset1 = builder
+            .try_create_shared_string("welcome to flatbuffers!!")
+            .unwrap();
+        let offset2 = builder.try_create_shared_string("welcome").unwrap();
+        let offset3 = builder
+            .try_create_shared_string("welcome to flatbuffers!!")
+            .unwrap();
+        assert_ne!(offset2.value(), offset3.value());
+        assert_eq!(offset1.value(), offset3.value());
+
+        builder.reset();
+        let offset4 = builder.try_create_shared_string("welcome").unwrap();
+        let offset5 = builder
+            .try_create_shared_string("welcome to flatbuffers!!")
+            .unwrap();
+        assert_ne!(offset2.value(), offset4.value());
+        assert_ne!(offset5.value(), offset1.value());
+
+        builder.reset();
+        // Shared strings work with an object in between writes
+        let name = builder.try_create_shared_string("foo").unwrap();
+        let enemy =
+            my_game::example::Monster::create(&mut builder, &my_game::example::MonsterArgs {
+                name: Some(name),
+                ..Default::default()
+            });
+        let secondary_name = builder.try_create_shared_string("foo").unwrap();
+        assert_eq!(name.value(), secondary_name.value());
+
+        let args = my_game::example::MonsterArgs {
+            name: Some(secondary_name),
+            enemy: Some(enemy),
+            testarrayofstring: Some(builder.try_create_vector(&[name, secondary_name]).unwrap()),
+            ..Default::default()
+        };
+        let main_monster = my_game::example::Monster::create(&mut builder, &args);
+        builder.try_finish(main_monster, None).unwrap();
+        let monster =
+            my_game::example::root_as_monster(builder.finished_data()).unwrap();
+
+        assert_eq!(monster.enemy().unwrap().name(), "foo");
+        let string_vector = monster.testarrayofstring().unwrap();
+        assert_eq!(string_vector.get(0), "foo");
+        assert_eq!(string_vector.get(1), "foo");
+    }
+
+    #[test]
+    fn try_vector_manual_build_roundtrip() {
+        // Build a vector of scalars manually using try_start_vector / try_push / try_end_vector.
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let items: Vec<u32> = vec![10, 20, 30, 40, 50];
+
+        builder
+            .try_start_vector::<u32>(items.len())
+            .unwrap();
+        for &v in items.iter().rev() {
+            builder.try_push::<u32>(v).unwrap();
+        }
+        let vecend = builder.try_end_vector::<u32>(items.len()).unwrap();
+        builder.try_finish_minimal(vecend).unwrap();
+
+        let buf = builder.finished_data();
+        let got = unsafe {
+            <flatbuffers::ForwardsUOffset<flatbuffers::Vector<u32>>>::follow(&buf[..], 0)
+        };
+        let result: Vec<u32> = got.iter().collect();
+        assert_eq!(result, items);
+    }
+
+    #[test]
+    fn try_create_vector_roundtrip() {
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let items: Vec<i64> = vec![-1, 0, 1, i64::MIN, i64::MAX];
+        let offset = builder.try_create_vector(&items).unwrap();
+        builder.try_finish_minimal(offset).unwrap();
+
+        let buf = builder.finished_data();
+        let got = unsafe {
+            <flatbuffers::ForwardsUOffset<flatbuffers::Vector<i64>>>::follow(&buf[..], 0)
+        };
+        let result: Vec<i64> = got.iter().collect();
+        assert_eq!(result, items);
+    }
+
+    #[test]
+    fn try_create_vector_from_iter_roundtrip() {
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let items: Vec<f64> = vec![1.0, 2.5, -3.14, 0.0];
+        let offset = builder
+            .try_create_vector_from_iter(items.iter().copied())
+            .unwrap();
+        builder.try_finish_minimal(offset).unwrap();
+
+        let buf = builder.finished_data();
+        let got = unsafe {
+            <flatbuffers::ForwardsUOffset<flatbuffers::Vector<f64>>>::follow(&buf[..], 0)
+        };
+        let result: Vec<f64> = got.iter().collect();
+        assert_eq!(result, items);
+    }
+
+    #[test]
+    fn try_create_byte_string_roundtrip() {
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let data = b"hello bytes";
+        let offset = builder.try_create_byte_string(data).unwrap();
+        builder.try_finish_minimal(offset).unwrap();
+
+        let buf = builder.finished_data();
+        let got = unsafe {
+            <flatbuffers::ForwardsUOffset<&[u8]>>::follow(&buf[..], 0)
+        };
+        assert_eq!(got, data);
+    }
+
+    #[test]
+    fn try_finish_size_prefixed_roundtrip() {
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let args = &my_game::example::MonsterArgs {
+            mana: 200,
+            hp: 300,
+            name: Some(builder.try_create_string("bob").unwrap()),
+            ..Default::default()
+        };
+        let mon = my_game::example::Monster::create(&mut builder, &args);
+        builder.try_finish_size_prefixed(mon, None).unwrap();
+
+        let buf = builder.finished_data();
+        let m = flatbuffers::size_prefixed_root::<my_game::example::Monster>(buf).unwrap();
+        assert_eq!(m.mana(), 200);
+        assert_eq!(m.hp(), 300);
+        assert_eq!(m.name(), "bob");
+    }
+
+    #[test]
+    fn try_finish_with_file_identifier() {
+        let mut builder = flatbuffers::FlatBufferBuilder::new();
+        let name = builder.try_create_string("foo").unwrap();
+        let args = &my_game::example::MonsterArgs {
+            name: Some(name),
+            hp: 42,
+            ..Default::default()
+        };
+        let mon = my_game::example::Monster::create(&mut builder, &args);
+        builder
+            .try_finish(mon, Some(my_game::example::MONSTER_IDENTIFIER))
+            .unwrap();
+
+        let buf = builder.finished_data();
+        assert!(my_game::example::monster_buffer_has_identifier(buf));
+        let m = my_game::example::root_as_monster(buf).unwrap();
+        assert_eq!(m.name(), "foo");
+        assert_eq!(m.hp(), 42);
+    }
+}
+
 }

tests/test.cpp

@@ -1774,6 +1774,7 @@ int FlatBufferTests(const std::string& tests_data_path) {
   FixedLengthArrayJsonTest(tests_data_path, false);
   FixedLengthArrayJsonTest(tests_data_path, true);
   ReflectionTest(tests_data_path, flatbuf.data(), flatbuf.size());
+  ForAllFieldsReverseTest(tests_data_path);
   ParseProtoTest(tests_data_path);
   EvolutionTest(tests_data_path);
   UnionDeprecationTest(tests_data_path);

tests/ts/TypeScriptTest.py

@@ -62,16 +62,10 @@ def flatc(
 
 # Execute esbuild with the specified parameters
 def esbuild(input, output):
-  cmd = ["esbuild", input, "--outfile=" + output]
+  cmd = ["../../node_modules/.bin/esbuild", input, "--outfile=" + output]
   cmd += ["--format=cjs", "--bundle", "--external:flatbuffers"]
   check_call(cmd)
 
-
-print("Removing node_modules/ directory...")
-shutil.rmtree(Path(tests_path, "node_modules"), ignore_errors=True)
-
-check_call(["npm", "install", "--silent"])
-
 flatc(
     options=[
         "--ts",
@@ -228,12 +222,12 @@ flatc(
 )
 
 print("Running TypeScript Compiler...")
-check_call(["tsc"])
+check_call(["../../node_modules/.bin/tsc"])
 print(
     "Running TypeScript Compiler in old node resolution mode for"
     " no_import_ext..."
 )
-check_call(["tsc", "-p", "./tsconfig.node.json"])
+check_call(["../../node_modules/.bin/tsc", "-p", "./tsconfig.node.json"])
 
 NODE_CMD = ["node"]
 

tests/ts/bazel_repository_test_dir/package.json

@@ -3,6 +3,6 @@
   "type": "module",
   "private": true,
   "devDependencies": {
-    "lodash": "4.17.23"
+    "lodash": "4.18.1"
   }
 }

tests/ts/package.json

@@ -1,6 +1,6 @@
 {
     "type": "module",
     "dependencies": {
-        "flatbuffers": "../../"
+        "flatbuffers": "workspace:*"
     }
 }

tests/ts/pnpm-lock.yaml

@@ -1,10 +0,0 @@
-lockfileVersion: '6.0'
-
-settings:
-  autoInstallPeers: true
-  excludeLinksFromLockfile: false
-
-dependencies:
-  flatbuffers:
-    specifier: ../../
-    version: link:../..

tests/union_name_test.fbs

@@ -0,0 +1,21 @@
+// Test for union creator naming consistency (issue #8843).
+// Uses non-UpperCamel union name to verify that Function() naming
+// is used consistently for both definition and call site.
+
+namespace union_name_test;
+
+table Foo {
+  val: int;
+}
+
+table Bar {
+  name: string;
+}
+
+union my_test_union { Foo, Bar }
+
+table Container {
+  u: my_test_union;
+}
+
+root_type Container;

tests/union_name_test/Bar.py

@@ -0,0 +1,93 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: union_name_test
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class Bar(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = Bar()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsBar(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # Bar
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Bar
+    def Name(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.String(o + self._tab.Pos)
+        return None
+
+def BarStart(builder):
+    builder.StartObject(1)
+
+def Start(builder):
+    BarStart(builder)
+
+def BarAddName(builder, name):
+    builder.PrependUOffsetTRelativeSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(name), 0)
+
+def AddName(builder, name):
+    BarAddName(builder, name)
+
+def BarEnd(builder):
+    return builder.EndObject()
+
+def End(builder):
+    return BarEnd(builder)
+
+
+class BarT(object):
+
+    # BarT
+    def __init__(
+        self,
+        name = None,
+    ):
+        self.name = name  # type: Optional[str]
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        bar = Bar()
+        bar.Init(buf, pos)
+        return cls.InitFromObj(bar)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, bar):
+        x = BarT()
+        x._UnPack(bar)
+        return x
+
+    # BarT
+    def _UnPack(self, bar):
+        if bar is None:
+            return
+        self.name = bar.Name()
+
+    # BarT
+    def Pack(self, builder):
+        if self.name is not None:
+            name = builder.CreateString(self.name)
+        BarStart(builder)
+        if self.name is not None:
+            BarAddName(builder, name)
+        bar = BarEnd(builder)
+        return bar

tests/union_name_test/Container.py

@@ -0,0 +1,120 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: union_name_test
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class Container(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = Container()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsContainer(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # Container
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Container
+    def UType(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Uint8Flags, o + self._tab.Pos)
+        return 0
+
+    # Container
+    def U(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(6))
+        if o != 0:
+            from flatbuffers.table import Table
+            obj = Table(bytearray(), 0)
+            self._tab.Union(obj, o)
+            return obj
+        return None
+
+def ContainerStart(builder):
+    builder.StartObject(2)
+
+def Start(builder):
+    ContainerStart(builder)
+
+def ContainerAddUType(builder, uType):
+    builder.PrependUint8Slot(0, uType, 0)
+
+def AddUType(builder, uType):
+    ContainerAddUType(builder, uType)
+
+def ContainerAddU(builder, u):
+    builder.PrependUOffsetTRelativeSlot(1, flatbuffers.number_types.UOffsetTFlags.py_type(u), 0)
+
+def AddU(builder, u):
+    ContainerAddU(builder, u)
+
+def ContainerEnd(builder):
+    return builder.EndObject()
+
+def End(builder):
+    return ContainerEnd(builder)
+
+import union_name_test.Bar
+import union_name_test.Foo
+import union_name_test.my_test_union
+try:
+    from typing import Union
+except:
+    pass
+
+class ContainerT(object):
+
+    # ContainerT
+    def __init__(
+        self,
+        uType = 0,
+        u = None,
+    ):
+        self.uType = uType  # type: int
+        self.u = u  # type: Union[None, 'union_name_test.Foo.FooT', 'union_name_test.Bar.BarT']
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        container = Container()
+        container.Init(buf, pos)
+        return cls.InitFromObj(container)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, container):
+        x = ContainerT()
+        x._UnPack(container)
+        return x
+
+    # ContainerT
+    def _UnPack(self, container):
+        if container is None:
+            return
+        self.uType = container.UType()
+        self.u = union_name_test.my_test_union.MyTestUnionCreator(self.uType, container.U())
+
+    # ContainerT
+    def Pack(self, builder):
+        if self.u is not None:
+            u = self.u.Pack(builder)
+        ContainerStart(builder)
+        ContainerAddUType(builder, self.uType)
+        if self.u is not None:
+            ContainerAddU(builder, u)
+        container = ContainerEnd(builder)
+        return container

tests/union_name_test/Foo.py

@@ -0,0 +1,90 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: union_name_test
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class Foo(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = Foo()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsFoo(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # Foo
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Foo
+    def Val(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Int32Flags, o + self._tab.Pos)
+        return 0
+
+def FooStart(builder):
+    builder.StartObject(1)
+
+def Start(builder):
+    FooStart(builder)
+
+def FooAddVal(builder, val):
+    builder.PrependInt32Slot(0, val, 0)
+
+def AddVal(builder, val):
+    FooAddVal(builder, val)
+
+def FooEnd(builder):
+    return builder.EndObject()
+
+def End(builder):
+    return FooEnd(builder)
+
+
+class FooT(object):
+
+    # FooT
+    def __init__(
+        self,
+        val = 0,
+    ):
+        self.val = val  # type: int
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        foo = Foo()
+        foo.Init(buf, pos)
+        return cls.InitFromObj(foo)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, foo):
+        x = FooT()
+        x._UnPack(foo)
+        return x
+
+    # FooT
+    def _UnPack(self, foo):
+        if foo is None:
+            return
+        self.val = foo.Val()
+
+    # FooT
+    def Pack(self, builder):
+        FooStart(builder)
+        FooAddVal(builder, self.val)
+        foo = FooEnd(builder)
+        return foo

tests/union_name_test/my_test_union.py

@@ -0,0 +1,20 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: union_name_test
+
+class my_test_union(object):
+    NONE = 0
+    Foo = 1
+    Bar = 2
+
+def MyTestUnionCreator(unionType, table):
+    from flatbuffers.table import Table
+    if not isinstance(table, Table):
+        return None
+    if unionType == my_test_union.Foo:
+        import union_name_test.Foo
+        return union_name_test.Foo.FooT.InitFromBuf(table.Bytes, table.Pos)
+    if unionType == my_test_union.Bar:
+        import union_name_test.Bar
+        return union_name_test.Bar.BarT.InitFromBuf(table.Bytes, table.Pos)
+    return None