Refactor WASM binding directory structure

* All tests moved into wasm/codegen/tests folder
* Merged wasm/codegen/helpers/ into wasm/codegen/generators/

PiperOrigin-RevId: 829471173
Change-Id: I2dbc5d9351771817ec260c7ddf87c31e66a9eabe

wasm/codegen/tests/bindings_diff_test.py

@@ -0,0 +1,47 @@
+# Copyright 2025 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from pathlib import Path
+
+from absl.testing import absltest
+
+from wasm.codegen.generators import binding_builder
+
+ERROR_MESSAGE = """
+The file '{}' needs to be updated, please run:
+update.py as described in wasm/README.md""".lstrip()
+
+
+class BindingsDiffTest(absltest.TestCase):
+
+  def test_bindings_source(self):
+    SCRIPT_DIR = Path(__file__).parent
+    with open(SCRIPT_DIR / 'generated/bindings.cc', 'r') as f:
+      self.generated_src = f.read()
+    self.template_path_cc = SCRIPT_DIR / 'templates/bindings.cc'
+
+    self.builder = binding_builder.BindingBuilder(self.template_path_cc)
+
+    generator_output = (
+        self.builder.set_enums().set_structs().set_functions().to_string()
+    )
+    self.assertEqual(
+        generator_output,
+        self.generated_src,
+        msg=ERROR_MESSAGE.format('bindings.cc'),
+    )
+
+
+if __name__ == '__main__':
+  absltest.main()