nodejs / nodejs/node

--test-name-pattern needing to come before filenames is hostile to npm scripts

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feature request never-stale test_runner
Dominant language
JavaScript
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Description

What is the problem this feature will solve?

It is common practice to set up npm scripts for testing. E.g.

{
  "test": "node --test tests/*.js more-tests/*.js"
}

However, this cannot be combined with --test-name-pattern. Attempting to do so, e.g.

npm test -- --test-name-pattern="my pattern"

will not work, because this gets translated to

node --test tests/*.js more-tests/*.js --test-name-pattern="my pattern"

which, I believe, ends up passing --test-name-pattern="my pattern" as an argument to these test files, instead of passing it as an argument to the test runner. The correct invocation is

node --test-name-pattern="my pattern" --test tests/*.js more-tests/*.js

but this is impossible to do via npm scripts, it seems. (See alternatives considered.)

What is the feature you are proposing to solve the problem?

I don't know what a good solution to this would be. Some possible ideas:

  • Special-case command line processing such that when --test is present, node grabs the --test-name-pattern argument for itself instead of passing it to scripts?

  • Introduce a new binary, e.g. node_test, which processes command-line arguments in such a way? I believe this is how most test runners behave.

  • Introduce a file-based customization of the test runner, including which tests to run, so that I don't have to pass the test filenames as arguments to the test runner in a way that causes this problem?

  • Improve npm scripts to support a better method of passing arguments in the middle of the script? (See below.)

What alternatives have you considered?

I investigated how to get npm scripts to substitute in arguments you pass to npm run into the script command, so that the translation becomes the correct one. This is a well-studied problem, and the following two Stack Overflow posts have the best answers, as far as I can tell:

None of them seem very satisfactory, unfortunately. In particular, if you want something that works cross-platform, you basically have to write a wrapper script.

As an alternative, I could continue using other test runners, which support npm scripts better.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the npm test invocation with --test-name-pattern and compare it with the working command where the option precedes --test and filenames. Investigate Node's --test and --test-name-pattern command-line handling; done requires a defined approach that supports this npm-script use case, likely with tests covering the argument order.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, node.js
Domain
cli, testing-qa
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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