Currently, we have a lot of duplication across the JS bundles that esbuild produces for each entry point. This PR fundamentally changes this as follows:

• All CodeQL Action code is now bundled into entry-points.js. This avoids significant duplication across the individual bundles, since most of the Action's code is shared among the different actions.
• We have new entry points for the individual actions, which import entry-points and call the relevant run function.
• In the esbuild configuration, we mark entry-points as external, so that it is not bundled up with the entry point wrappers.

This reduces the size of the compressed repo. I tested the impact of this locally with a fresh, shallow checkout of the repo:

$ git clone git@github.com:github/codeql-action --depth=1 --branch mbg/esbuild/split
$ cd codeql-action
$ tar -czvf *

The resulting .tar.gz file is around ~2.9M. This is approximately a 70% reduction in archive size.

Risk assessment

For internal use only. Please select the risk level of this change:

• High risk: Changes are not fully under feature flags, have limited visibility and/or cannot be tested outside of production.

Which use cases does this change impact?

Workflow types:

• Advanced setup - Impacts users who have custom CodeQL workflows.
• Managed - Impacts users with dynamic workflows (Default Setup, Code Quality, ...).

Products:

• Code Scanning - The changes impact analyses when analysis-kinds: code-scanning.
• Code Quality - The changes impact analyses when analysis-kinds: code-quality.
• Other first-party - The changes impact other first-party analyses.
• Third-party analyses - The changes affect the upload-sarif action.

Environments:

• Dotcom - Impacts CodeQL workflows on github.com and/or GitHub Enterprise Cloud with Data Residency.
• GHES - Impacts CodeQL workflows on GitHub Enterprise Server.
• Testing/None - This change does not impact any CodeQL workflows in production.

How did/will you validate this change?

• Test repository - This change will be tested on a test repository before merging.
• Unit tests - I am depending on unit test coverage (i.e. tests in .test.ts files).
• End-to-end tests - I am depending on PR checks (i.e. tests in pr-checks).

If something goes wrong after this change is released, what are the mitigation and rollback strategies?

• Rollback - Change can only be disabled by rolling back the release or releasing a new version with a fix.

How will you know if something goes wrong after this change is released?

• Telemetry - I rely on existing telemetry or have made changes to the telemetry.
  • Dashboards - I will watch relevant dashboards for issues after the release. Consider whether this requires this change to be released at a particular time rather than as part of a regular release.
  • Alerts - New or existing monitors will trip if something goes wrong with this change.

Are there any special considerations for merging or releasing this change?

• No special considerations - This change can be merged at any time.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Consider adding a changelog entry for this change.
• Confirm the readme and docs have been updated if necessary.