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;
   }
 

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()),
         )?;
     }
 

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]));
   }
 }
 

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/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:../..