[TS/JS] Entry point per namespace and reworked 1.x compatible single file build (#7510)

* [TS/JS] Entry point per namespace

* Fix handling of outputpath and array_test

* Attempt to fix generate_code

* Fix cwd for ts in generate_code

* Attempt to fixup bazel and some docs

* Add --ts-flat-files to bazel build to get bundle

* Move to DEFAULT_FLATC_TS_ARGS

* Attempt to add esbuild

* Attempt to use npm instead

* Remove futile attempt to add esbuild

* Attempt to as bazel esbuild

* Shuffle

* Upgrade bazel deps

* Revert failed attempts to get bazel working

* Ignore flatc tests for now

* Add esbuild dependency

* `package.json` Include esbuild

* `WORKSPACE` Add fetching esbuild binary

* Update WORKSPACE

* Unfreeze Lockfile

* Update WORKSPACE

* Update BUILD.bazel

* Rework to suggest instead of running external bundler

* Add esbuild generation to test script

* Prelim bundle test

* Run test JavaScriptTest from flatbuffers 1.x

* Deps upgrade

* Clang format fix

* Revert bazel changes

* Fix newline

* Generate with type declarations

* Handle "empty" root namespace

* Adjust tests for typescript_keywords.ts

* Separate test procedure for old node resolution module output

* Fix rel path for root level re-exports

* Bazel support for esbuild-based flatc

Unfortunately, we lose typing information because the new esbuild method
of generating single files does not generate type information.

The method used here is a bit hack-ish because it relies on parsing the
console output of flatc to figure out what to do.

* Try to fix bazel build for when node isn't present on host

* Auto formatting fixes

* Fix missing generated code

Co-authored-by: Derek Bailey <derekbailey@google.com>
Co-authored-by: James Kuszmaul <jabukuszmaul+collab@gmail.com>

build_defs.bzl

@@ -7,7 +7,7 @@ Rules for building C++ flatbuffers with Bazel.
 
 load("@rules_cc//cc:defs.bzl", "cc_library")
 
-flatc_path = "@com_github_google_flatbuffers//:flatc"
+TRUE_FLATC_PATH = "@com_github_google_flatbuffers//:flatc"
 
 DEFAULT_INCLUDE_PATHS = [
     "./",
@@ -16,6 +16,14 @@ DEFAULT_INCLUDE_PATHS = [
     "$(execpath @com_github_google_flatbuffers//:flatc).runfiles/com_github_google_flatbuffers",
 ]
 
+def default_include_paths(flatc_path):
+    return [
+        "./",
+        "$(GENDIR)",
+        "$(BINDIR)",
+        "$(execpath %s).runfiles/com_github_google_flatbuffers" % (flatc_path),
+    ]
+
 DEFAULT_FLATC_ARGS = [
     "--gen-object-api",
     "--gen-compare",
@@ -32,13 +40,14 @@ def flatbuffer_library_public(
         language_flag,
         out_prefix = "",
         includes = [],
-        include_paths = DEFAULT_INCLUDE_PATHS,
+        include_paths = None,
         flatc_args = DEFAULT_FLATC_ARGS,
         reflection_name = "",
         reflection_visibility = None,
         compatible_with = None,
         restricted_to = None,
         target_compatible_with = None,
+        flatc_path = "@com_github_google_flatbuffers//:flatc",
         output_to_bindir = False):
     """Generates code files for reading/writing the given flatbuffers in the requested language using the public compiler.
 
@@ -62,6 +71,7 @@ def flatbuffer_library_public(
         for, instead of default-supported environments.
       target_compatible_with: Optional, The list of target platform constraints
         to use.
+      flatc_path: Bazel target corresponding to the flatc compiler to use.
       output_to_bindir: Passed to genrule for output to bin directory.
 
 
@@ -69,6 +79,8 @@ def flatbuffer_library_public(
     optionally a Fileset([reflection_name]) with all generated reflection
     binaries.
     """
+    if include_paths == None:
+        include_paths = default_include_paths(flatc_path)
     include_paths_cmd = ["-I %s" % (s) for s in include_paths]
 
     # '$(@D)' when given a single source target will give the appropriate
@@ -80,7 +92,7 @@ def flatbuffer_library_public(
     genrule_cmd = " ".join([
         "SRCS=($(SRCS));",
         "for f in $${SRCS[@]:0:%s}; do" % len(srcs),
-        "$(location %s)" % (flatc_path),
+        "OUTPUT_FILE=\"$(OUTS)\" $(location %s)" % (flatc_path),
         " ".join(include_paths_cmd),
         " ".join(flatc_args),
         language_flag,
@@ -104,7 +116,7 @@ def flatbuffer_library_public(
         reflection_genrule_cmd = " ".join([
             "SRCS=($(SRCS));",
             "for f in $${SRCS[@]:0:%s}; do" % len(srcs),
-            "$(location %s)" % (flatc_path),
+            "$(location %s)" % (TRUE_FLATC_PATH),
             "-b --schema",
             " ".join(flatc_args),
             " ".join(include_paths_cmd),
@@ -122,7 +134,7 @@ def flatbuffer_library_public(
             srcs = srcs + includes,
             outs = reflection_outs,
             output_to_bindir = output_to_bindir,
-            tools = [flatc_path],
+            tools = [TRUE_FLATC_PATH],
             compatible_with = compatible_with,
             restricted_to = restricted_to,
             target_compatible_with = target_compatible_with,
@@ -145,7 +157,7 @@ def flatbuffer_cc_library(
         out_prefix = "",
         deps = [],
         includes = [],
-        include_paths = DEFAULT_INCLUDE_PATHS,
+        include_paths = None,
         cc_include_paths = [],
         flatc_args = DEFAULT_FLATC_ARGS,
         visibility = None,