eric sciple
2816233a40
In YAML, block scalars (`|` and `>`) silently add a trailing newline by default
("clip" chomping). This can cause subtle bugs when the newline is unintentional.
This PR adds a warning when clip chomping is used in fields where trailing
newlines commonly cause issues:
- Environment variables (workflow, job, step, container, service levels)
- Action inputs (`with:`)
- Reusable workflow inputs and secrets
- Job outputs
- Matrix values (including `include` and `exclude`)
- Concurrency groups
The warning suggests using `|-` (strip) or `|+` (keep) to be explicit.
Intentionally does NOT warn for:
- `run:` scripts (trailing newlines are normal)
- Fields trimmed server-side (`if:`, `name:`, `runs-on:`, etc.)
The feature is gated behind the `blockScalarChompingWarning` feature flag.
actions/expressions
@actions/expressions is a library to parse and evaluate GitHub Actions expressions.
Installation
The package contains TypeScript types and compiled ECMAScript modules.
npm install @actions/expressions
Usage
Simple example
import { Parser, Lexer, Evaluator, data } from '@actions/expressions';
const lexer = new Lexer("1 == 2");
const lr = lexer.lex();
const parser = new Parser(lr.tokens, [], []);
const expr = parser.parse();
const evaluator = new Evaluator(expr, new data.Dictionary());
const result = evaluator.evaluate();
console.log(result.coerceString()) // false
With context data
import { Parser, Lexer, Evaluator, data } from '@actions/expressions';
const lexer = new Lexer("'monalisa' == context.name");
const lr = lexer.lex();
const parser = new Parser(lr.tokens, ["context"], []);
const expr = parser.parse();
const evaluator = new Evaluator(expr, new data.Dictionary([{
key: "context"
value: new data.Dictionary([{
key: "name"
value: new data.StringData("monalisa")
}])
}]));
const result = evaluator.evaluate();
console.log(result.coerceString()) // true
Contributing
See CONTRIBUTING.md at the root of the repository for general guidelines and recommendations.
This project is just one of multiple implementations of the GitHub Actions Expressions language. We therefore cannot accept contributions that add new language features or significantly change the behavior of existing language features. If you would like to propose a change to the language itself, please use our Community Forum.
If you do want to contribute, please run prettier to format your code and add unit tests as appropriate before submitting your PR. ./testdata contains test cases that all implementations should pass, please also make sure those tests are still passing.
Build
npm run build
or to watch for changes
npm run watch
Test
npm test
or to watch for changes and run tests:
npm run test-watch
Lint
npm run format-check
License
This project is licensed under the terms of the MIT open source license. Please refer to MIT for the full terms.