Let Jest handle all file types

[gaearon]

In 0.8.x, we switched to treat all non-JS/CSS extensions as files by default (#1059, #1077).

However when we tried to do the same in Jest, we made a mistake which introduced false positives (#1145, #1147).

We temporarily reverted this change in #1149 and reopened #667 (comment). @cpojer suggested to use transform instead of moduleNameMapper so that we can match against the full paths.

This PR implements that. I verified that the following cases work:

• Importing CSS both inside project directory and in node_modules (gives you `{})
• Importing arbitrary files both inside project directory and in node_modules (gives you the filename)
• Importing JS modules like ../something or lodash.assign (covers Upgrading to 0.8.0 will break imports from outside of the test's directory #1145, FileStub.js used for lodash modules :-( #1147).

Fixes #667.

[gaearon]

I needed this because otherwise we can't import CSS from node_modules (e.g. bootstrap/dist/bootstrap.css). Would it make sense to change the default to that?

[cpojer]

should this not include the extension name?

[gaearon]

I think it does!

 require('path').basename('aas.asa') 'aas.asa'

[cpojer]

nice!

[gaearon]

Tested with:

import React, { Component } from 'react'; import appCss from './App.css'; import depCss from 'postcss-discard-overridden/test/input.css'; import appSVG from './logo.svg'; import depSVG from 'postcss-load-options/logo.svg'; import appNoExt from './noext'; import depNoExt from 'abbrev/LICENSE'; import appUnknown from './lol.unknown'; // I added this import depUnknown from 'abab/lol.unknown'; // I added this import depJS from 'abab/lol'; // I added this, it's just module.exports = function() { return `haha` } class App extends Component { render() { return ( <div className="App"> app css: {JSON.stringify(appCss)} <br />{'\n'} dep css: {JSON.stringify(depCss)} <br />{'\n'} app svg: {appSVG} <br />{'\n'} dep svg: {depSVG} <br />{'\n'} app noExt: {appNoExt} <br />{'\n'} dep noExt: {depNoExt} <br />{'\n'} app unknown: {appUnknown} <br />{'\n'} dep unknown: {depUnknown} <br />{'\n'} dep js {depJS()}{depJS.toString()} </div> ); } } export default App;

(Need to add something like this to integration test, see #1187)

npm start

npm test

npm start post ejection

npm test post ejection

[EnoahNetzach]

I already added this to the todo list of #1187 ;)