@typeorm/codemod

Automated code migration tool for TypeORM version upgrades.

Usage

# Run all v1 transforms
npx @typeorm/codemod v1 src/

# Dry run (preview changes without writing)
npx @typeorm/codemod v1 --dry src/

# Run a specific transform
npx @typeorm/codemod v1 --transform connection-to-datasource src/

# Exclude files by glob pattern (repeatable)
npx @typeorm/codemod v1 --ignore '**/generated*' --ignore '**/e2e/**' src/

# Control parallelism
npx @typeorm/codemod v1 --workers 4 src/

# List available transforms
npx @typeorm/codemod v1 --list

Options

| Option | Short | Description | | -------------------- | ----- | --------------------------------------------------- | | --dry | -d | Dry run (show changes without writing) | | --help | -h | Show help | | --ignore <pattern> | -i | Glob pattern to exclude files (repeatable) | | --list | -l | List available transforms | | --transform <name> | -t | Run a specific transform only | | --workers <num> | -w | Number of worker processes (default: CPU cores - 1) |

After running

Some transforms leave TODO comments in your code where manual changes are needed. After the codemod completes, it will list all files that require manual review.

Formatting

The codemod uses an AST-based approach which may introduce minor formatting differences (e.g. extra parentheses, quote style changes). Run your project's formatter after the codemod to restore your code style:

npx @typeorm/codemod v1 src/
npx prettier --write src/        # or: npx eslint --fix src/

Scoping

Transforms that rename properties or methods (e.g. .connection to .dataSource) rely on type annotations to identify TypeORM instances. Code that uses TypeORM APIs without type annotations may not be transformed automatically — review git diff after running.

Documentation

See the full migration guide for details on all breaking changes:

• v1