eslint-plugin-cdk
Eslint plugin for the CDK repository. Contains rules that need to be applied specific to the CDK repository.
Rules
-
invalid-cfn-imports: Ensures that imports of Cfn<Resource> L1 resources come from the stable
aws-cdk-lib package and not the alpha packages. Rule only applies to alpha modules.
-
no-core-construct: Forbid the use of Construct and IConstruct from the "@aws-cdk/core" module.
Instead use Construct and IConstruct from the "constructs" module.
Rule only applies to typescript files under the test/ folder.
-
no-invalid-path: Checks paths specified using path.join() for validity, including not going backwards ('..')
multiple times in the path and not going backwards beyond a package's package.json.
-
no-literal-partition: Forbids the use of literal partitions (usually aws). Instead, use
Aws.PARTITION to ensure that the code works for other partitions too.
-
consider-promise-all: when using Promise.all(), attest that there is no unbounded parallelism.
How to add new rules
- Make a new file in
lib/rules. It should export one function called create. The
create function should return a visitor object.
- Add the new file to
lib/index.ts.
- Add a fixture directory under
test/fixtures/<rule name>. Copy and adjust an eslintrc.js file
from another test.
- Add a testing
.ts file, and be sure to add either an expected.ts or an .error.txt variant
as well!
- You can now run the test in debugging mode (make sure to have
npx tsc -w running, then from a debugging terminal, npx jest --no-coverage -it 'your rule name'), set a breakpoint, and inspect the typeless objects.
Use https://ts-ast-viewer.com/ to get a feel for the AST you're trying to analyze. Note
that eslint uses estree to model AST nodes (not the TypeScript AST nodes), but they are
often comparable. Add type-testing TypeScript helpers to type-checkers.ts for typing
assistance.
To activate it for real on the repo, also add it to cdk-build-tools/config/eslintrc.js.
