To completely remove the generation and maintenance of snippet_metadata_*.json files across the Node.js client libraries, as these files are no longer actively use (seee go/snippet-gen-design).

Proposed Changes

1. TypeScript Generator (gapic-generator-typescript)

The generator is the source of these files. We should stop it from emitting them entirely.

• Modify templater.ts:
  • Remove the if (outputFilename.match(/snippet_metadata/)) block in processOneTemplate(). This block currently bypasses standard template rendering to manually construct the JSON metadata.
  • Remove the createSnippetIndexMetadata() and createSnippetMetadata() helper functions.
  • Remove the countRegionTagLines() and findRegionTag() helpers if they are not used elsewhere.
• Cleanup Templates:
  • Delete templates/esm/typescript_samples/samples/generated/$version/snippet_metadata_$apiNamingProtoPackage.json.njk.
  • Delete templates/cjs/typescript_samples/samples/generated/$version/snippet_metadata_$apiNamingProtoPackage.json.njk.

2. Librarian (googleapis/librarian)

Librarian currently contains post-processing logic to update the hardcoded 0.1.0 version in these files.

• Modify internal/librarian/nodejs/generate.go:
  • Remove the call to updateSnippetMetadataVersion().
  • Delete the updateSnippetMetadataVersion() function and its related types (snippetMetadata, clientLibrary).
• Cleanup v1small Workarounds:
  • The v1small skip in updateSnippetMetadataVersion() can be removed once the function is deleted.

3. Cleanup PR (Monorepo-wide)

Once generation is disabled, we should perform one final sweep of the monorepo to delete all existing snippet_metadata_*.json files to avoid having orphaned files.

Implementation Path

1. Submit PR to google-cloud-node (or gapic-generator-typescript repo) to disable generation.
2. Submit PR to librarian to remove the version-updating post-processor.
3. Execute a monorepo-wide deletion PR (similar to Task 5.3) for all modern UNDERSCORE metadata files.

Benefits

• Reduced Diff Noise: Eliminates a large source of churn (version bumps and line shifts) in every generation PR.
• Faster Generation: Skips the expensive template scanning and region tag counting logic in the generator.
• Cleaner Pipeline: Removes complex post-processing logic from Librarian.
• Reduces Toil:: addresses Nodejs: 0.1.0 Snippet Metadata Version Leakage synthtool#2173