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Helper to create .flowconfig module name mapper
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| #!/usr/bin/env node | |
| /** | |
| * Flowtype understands Node (or Haste) imports but not Webpack. | |
| * | |
| * Many codebases have webpack set up like: | |
| * src/foo.js | |
| * src/components/Bar.jsx | |
| * | |
| * And then import them like `require('foo')` or `require/components/Bar.jsx` | |
| * | |
| * Flow doesn't understand this by default. A solution that used to work was to convince | |
| * it that `src` was a source of Node modules (https://github.com/facebook/flow/issues/382) | |
| * | |
| * In Flow 0.57 they introduced an optimization to "only check the files in | |
| node_modules/ which are direct or transitive dependencies of the non- | |
| node_modules code." (https://github.com/facebook/flow/blob/master/Changelog.md#0570) | |
| * Because the trick above made Flow think your app modules were another source of node_modules, | |
| * now the app source would not be focused either. You could see this in Flow logs by | |
| * almost all app files being omitted from the "focused" count. | |
| * | |
| * A working alternative is to explicitly define `module.name_mapper` directives for each | |
| * child of your root directory, to tell Flow how to resolve those files. (Thanks to | |
| * https://github.com/cdebotton/react-universal/commit/e57aadbcbd8be4e2031f308187392f44d02b44f9#commitcomment-19062820 | |
| * for the idea.) | |
| * | |
| * This script generates the directives you need in [options] of your `.flowconfig`. | |
| * | |
| * Set ROOT_APP_DIR if yours is not src/. | |
| */ | |
| const fs = require('fs'); | |
| const path = require('path'); | |
| const ROOT_APP_DIR = 'app/j'; | |
| const files = fs.readdirSync(ROOT_APP_DIR); | |
| const jsList = []; | |
| const dirList = []; | |
| for (const filename of files) { | |
| if (filename.startsWith('.')) continue; | |
| const isDirectory = fs.statSync(path.join(ROOT_APP_DIR, filename)).isDirectory(); | |
| if (isDirectory) { | |
| dirList.push(filename); | |
| } else { | |
| const moduleName = path.basename(filename, '.js'); | |
| jsList.push(moduleName); | |
| } | |
| } | |
| console.log(`# Generated by https://gist.github.com/turadg/4c11ef9ac1af7b41276d0acc4d4bf8c8 with root ${ROOT_APP_DIR}`); | |
| const dirMatcher = dirList.join('\\|'); | |
| console.log( | |
| `module.name_mapper='^\\(${dirMatcher}\\)\\/\\(.*\\)$' -> '<PROJECT_ROOT>/${ROOT_APP_DIR}/\\1/\\2'` | |
| ); | |
| console.log( | |
| `module.name_mapper='^\\(${dirMatcher}\\)$' -> '<PROJECT_ROOT>/${ROOT_APP_DIR}/\\1/index'` | |
| ); | |
| const jsMatcher = jsList.join('\\|'); | |
| console.log(`module.name_mapper='^\\(${jsMatcher}\\)$' -> '<PROJECT_ROOT>/${ROOT_APP_DIR}/\\1'`); |
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