isMacrosName doesn't provide the full path

• babel-plugin-macros version: 3.1.0
• node version: 12.x
• npm version: 6.14

Relevant code or config

const macrosRegex = /[./]macro(\.js)?$/;
const testMacrosRegex = v =>
  macrosRegex.test(v) && v.indexOf('foobar/macro') === -1;

module.exports = {
  plugins: [
    [
      'macros',
      {
        isMacrosName: testMacrosRegex,
      },
    ],
  ],
};

File structure:

node_modules
  foobar
    index.js
    macro.js
app.js

// node_modules/foobar/index.js
import macro from './macro';

// app.js
import foobar from 'foobar';

What you did:

I tried to exclude foobar/macro from babel-plugin-macros

What happened:

The file is treated as a Babel macro.

Problem description:

The problem I’m having is with relative macro-like imports such as:

import macro from './macro';

The above code is trying to import a file named macro but that is not a Babel macro.

The custom configuration isn’t able to filter out this specific import because the path provided to testMacrosRegex is ./macro rather than the absolute one (node_modules/foobar/macro).

Suggested solution:

isMacrosName should provide an “absolute-like” import (starting from the root of the project) in order to allow to filter out unwanted macro files.

Alternatively, the plugin could provide a configuration option to specify paths that should be ignored.

[conartist6]

Here’s my summation: since babel-plugin-macros works by “stealing” some syntaxes that would otherwise be valid JS, it must never be run on code that has not explicitly opted into being transpiled with the macros plugin. This is not a flaw, but rather an explicit design choice.

This issue seems to have been caused by a bad jest configuration. In create-react-app the default set of babel transforms includes babel-plugin-macros, and that set of transforms is configured to run only on files which are not inside node_modules. The submitter configured jest with transformIgnorePatterns: ['node_modules/(?!pgk_name/)'], where pkg_name is the name of a package which has syntactic conflicts with macros. The problem appears to be that method of reconfiguring jest, which causes it to apply a set of plugins which includes macros to module code, which is incorrect. Explicitly applying the babel-jest transform to that package should be fine though.

[conartist6]

All that said, I do think isMacrosName has clear room for improvement. I think it should be given a second argument: the path of the file the import or require statement appears in. This would retain backwards compatibility but also ensure that any valid use cases could be met. But if I am right about what your problem is it would not be the solution you need.