AST generator

This script creates Abstract Syntax Tree (AST) of all JS/TS files in JSON format. The AST is created by using the bundled babel parser (for JavaScript, TypeScript). Type maps are generated using the Typescript compiler / type checker API.

Supported languages

Language	Tool used	Notes
JavaScript	babel	types via tsc
TypeScript	babel	types via tsc
Vue	babel
JSX	babel
TSX	babel

Usage

Building

yarn install
yarn build

Platform-specific binaries can now be build using pkg:

yarn binary

Testing

yarn install
yarn build
yarn test

This will use jest with ts-jest to run the tests in test/.

Regression Testing

The regression harness compares AST and type-map output between two versions of astgen (base branch vs. PR) across two real-world TypeScript corpora: typeorm@0.3.21 and fastify@v5.3.3.

Run locally (compares current branch against main):

yarn regression

To compare against a different base branch:

python3 scripts/regression-local.py --base-branch <branch>

The script builds both versions, clones the corpora, runs astgen on each, and prints a Markdown report to stdout showing:

• AST and typemap file counts and total sizes
• Wall-clock execution time
• Per-file content diffs (collapsible, truncated to 200 lines)

CI: The regression workflow runs automatically on every pull request (.github/workflows/regression.yml) and posts or updates a comment on the PR with the full report.

Getting Help

./astgen -h
Options:
  -v, --version  Print version number                                  [boolean]
  -i, --src      Source directory                                 [default: "."]
  -o, --output   Output directory for generated AST json files
                                                            [default: "ast_out"]
  -t, --type     Project type. Default auto-detect
  -r, --recurse  Recurse mode suitable for mono-repos  [boolean] [default: true]
  -h             Show help                                             [boolean]

Example

Navigate to the project and run astgen command.

cd <path to project>
astgen

To specify the project type and the path to the project.

astgen -t js -i <path to project>
astgen -t vue -i <path containing .vue files>