filePath is not provided to parser in parserOptions

[sompylasar]

I'm trying to make a conditional eslint parser which decides based on filename which parser to execute: Babel or TypeScript (because my project will soon contain both types of files which need to live together under a single eslint config for some time).

The native eslint parse call provides filePath in the parserOptions, which turned out the only and the very useful way to determine the file name:
https://github.com/eslint/eslint/blob/3ec436eeed0b0271e2ed0d0cb22e4246eb15f137/lib/linter.js#L637

function parse(text, config, filePath, messages) {

    let parser,
        parserOptions = {
            loc: true,
            range: true,
            raw: true,
            tokens: true,
            comment: true,
            filePath
        };

But when eslint-plugin-import parses its dependencies, it calls the custom parser on its own, and does not provide filePath in parserOptions:
https://github.com/benmosher/eslint-plugin-import/blob/90ef48b3ade57c77526b285f75dc0cfc41537831/utils/parse.js#L28

exports.default = function parse(path, content, context) {

  if (context == null) throw new Error('need context to parse properly')

  let parserOptions = context.parserOptions
  const parserPath = getParserPath(path, context)

  if (!parserPath) throw new Error('parserPath is required!')

  // hack: espree blows up with frozen options
  parserOptions = Object.assign({}, parserOptions)
  parserOptions.ecmaFeatures = Object.assign({}, parserOptions.ecmaFeatures)

  // always attach comments
  parserOptions.attachComment = true

  // require the parser relative to the main module (i.e., ESLint)
  const parser = moduleRequire(parserPath)

  return parser.parse(content, parserOptions)
}

This should not be a big change to add that, I'll propose a PR soon.

[benmosher]

makes sense to me 👍

[benmosher]

published under v2.4.0, thanks!

[benmosher]

uh oh, seems to break the cache! not sure why this isn't caught by tests but it introduces a substantial perf + memory regression. unpublishing v2.1.0 of eslint-module-utils!

[sompylasar]

@benmosher What? 0_o Which cache? How did you spot the regression?

[sompylasar]

Cache issue investigation here: #863

[benmosher]

reiterating here: I determined the leak is in memo-parser which I am probably the only person using. (or we'll find out soon enough)

republished with v2.1.1 of utils 👍🏻