cloudflare/cloudflare-typescript
Publicmirrored from https://github.com/cloudflare/cloudflare-typescriptAvailable
scripts/postprocess-files.cjs
165lines · modeblame
2d51afdcstainless-app[bot]2 years ago | 1 | const fs = require('fs'); |
| 2 | const path = require('path'); | |
| 3 | const { parse } = require('@typescript-eslint/parser'); | |
| 4 | | |
| 5 | const pkgImportPath = process.env['PKG_IMPORT_PATH'] ?? 'cloudflare/' | |
| 6 | | |
| 7 | const distDir = | |
| 8 | process.env['DIST_PATH'] ? | |
| 9 | path.resolve(process.env['DIST_PATH']) | |
| 10 | : path.resolve(__dirname, '..', 'dist'); | |
| 11 | const distSrcDir = path.join(distDir, 'src'); | |
| 12 | | |
| 13 | /** | |
| 14 | * Quick and dirty AST traversal | |
| 15 | */ | |
| 16 | function traverse(node, visitor) { | |
| 17 | if (!node || typeof node.type !== 'string') return; | |
| 18 | visitor.node?.(node); | |
| 19 | visitor[node.type]?.(node); | |
| 20 | for (const key in node) { | |
| 21 | const value = node[key]; | |
| 22 | if (Array.isArray(value)) { | |
| 23 | for (const elem of value) traverse(elem, visitor); | |
| 24 | } else if (value instanceof Object) { | |
| 25 | traverse(value, visitor); | |
| 26 | } | |
| 27 | } | |
| 28 | } | |
| 29 | | |
| 30 | /** | |
| 31 | * Helper method for replacing arbitrary ranges of text in input code. | |
| 32 | * | |
| 33 | * The `replacer` is a function that will be called with a mini-api. For example: | |
| 34 | * | |
| 35 | * replaceRanges('foobar', ({ replace }) => replace([0, 3], 'baz')) // 'bazbar' | |
| 36 | * | |
| 37 | * The replaced ranges must not be overlapping. | |
| 38 | */ | |
| 39 | function replaceRanges(code, replacer) { | |
| 40 | const replacements = []; | |
| 41 | replacer({ replace: (range, replacement) => replacements.push({ range, replacement }) }); | |
| 42 | | |
| 43 | if (!replacements.length) return code; | |
| 44 | replacements.sort((a, b) => a.range[0] - b.range[0]); | |
| 45 | const overlapIndex = replacements.findIndex( | |
| 46 | (r, index) => index > 0 && replacements[index - 1].range[1] > r.range[0], | |
| 47 | ); | |
| 48 | if (overlapIndex >= 0) { | |
| 49 | throw new Error( | |
| 50 | `replacements overlap: ${JSON.stringify(replacements[overlapIndex - 1])} and ${JSON.stringify( | |
| 51 | replacements[overlapIndex], | |
| 52 | )}`, | |
| 53 | ); | |
| 54 | } | |
| 55 | | |
| 56 | const parts = []; | |
| 57 | let end = 0; | |
| 58 | for (const { | |
| 59 | range: [from, to], | |
| 60 | replacement, | |
| 61 | } of replacements) { | |
| 62 | if (from > end) parts.push(code.substring(end, from)); | |
| 63 | parts.push(replacement); | |
| 64 | end = to; | |
| 65 | } | |
| 66 | if (end < code.length) parts.push(code.substring(end)); | |
| 67 | return parts.join(''); | |
| 68 | } | |
| 69 | | |
| 70 | /** | |
| 71 | * Like calling .map(), where the iteratee is called on the path in every import or export from statement. | |
| 72 | * @returns the transformed code | |
| 73 | */ | |
| 74 | function mapModulePaths(code, iteratee) { | |
| 75 | const ast = parse(code, { range: true }); | |
| 76 | return replaceRanges(code, ({ replace }) => | |
| 77 | traverse(ast, { | |
| 78 | node(node) { | |
| 79 | switch (node.type) { | |
| 80 | case 'ImportDeclaration': | |
| 81 | case 'ExportNamedDeclaration': | |
| 82 | case 'ExportAllDeclaration': | |
| 83 | case 'ImportExpression': | |
| 84 | if (node.source) { | |
| 85 | const { range, value } = node.source; | |
| 86 | const transformed = iteratee(value); | |
| 87 | if (transformed !== value) { | |
| 88 | replace(range, JSON.stringify(transformed)); | |
| 89 | } | |
| 90 | } | |
| 91 | } | |
| 92 | }, | |
| 93 | }), | |
| 94 | ); | |
| 95 | } | |
| 96 | | |
| 97 | async function* walk(dir) { | |
| 98 | for await (const d of await fs.promises.opendir(dir)) { | |
| 99 | const entry = path.join(dir, d.name); | |
| 100 | if (d.isDirectory()) yield* walk(entry); | |
| 101 | else if (d.isFile()) yield entry; | |
| 102 | } | |
| 103 | } | |
| 104 | | |
| 105 | async function postprocess() { | |
| 106 | for await (const file of walk(path.resolve(__dirname, '..', 'dist'))) { | |
| 107 | if (!/\.([cm]?js|(\.d)?[cm]?ts)$/.test(file)) continue; | |
| 108 | | |
| 109 | const code = await fs.promises.readFile(file, 'utf8'); | |
| 110 | | |
| 111 | let transformed = mapModulePaths(code, (importPath) => { | |
| 112 | if (file.startsWith(distSrcDir)) { | |
| 113 | if (importPath.startsWith(pkgImportPath)) { | |
| 114 | // convert self-references in dist/src to relative paths | |
| 115 | let relativePath = path.relative( | |
| 116 | path.dirname(file), | |
| 117 | path.join(distSrcDir, importPath.substring(pkgImportPath.length)), | |
| 118 | ); | |
| 119 | if (!relativePath.startsWith('.')) relativePath = `./${relativePath}`; | |
| 120 | return relativePath; | |
| 121 | } | |
| 122 | return importPath; | |
| 123 | } | |
| 124 | if (importPath.startsWith('.')) { | |
| 125 | // add explicit file extensions to relative imports | |
| 126 | const { dir, name } = path.parse(importPath); | |
| 127 | const ext = /\.mjs$/.test(file) ? '.mjs' : '.js'; | |
| 128 | return `${dir}/${name}${ext}`; | |
| 129 | } | |
| 130 | return importPath; | |
| 131 | }); | |
| 132 | | |
| 133 | if (file.startsWith(distSrcDir) && !file.endsWith('_shims/index.d.ts')) { | |
| 134 | // strip out `unknown extends Foo ? never :` shim guards in dist/src | |
| 135 | // to prevent errors from appearing in Go To Source | |
| 136 | transformed = transformed.replace( | |
| 137 | new RegExp('unknown extends (typeof )?\\S+ \\? \\S+ :\\s*'.replace(/\s+/, '\\s+'), 'gm'), | |
| 138 | // replace with same number of characters to avoid breaking source maps | |
| 139 | (match) => ' '.repeat(match.length), | |
| 140 | ); | |
| 141 | } | |
| 142 | | |
| 143 | if (file.endsWith('.d.ts')) { | |
| 144 | // work around bad tsc behavior | |
| 145 | // if we have `import { type Readable } from 'cloudflare/_shims/index'`, | |
| 146 | // tsc sometimes replaces `Readable` with `import("stream").Readable` inline | |
| 147 | // in the output .d.ts | |
| 148 | transformed = transformed.replace(/import\("stream"\).Readable/g, 'Readable'); | |
| 149 | } | |
| 150 | | |
| 151 | // strip out lib="dom" and types="node" references; these are needed at build time, | |
| 152 | // but would pollute the user's TS environment | |
| 153 | transformed = transformed.replace( | |
| 154 | /^ *\/\/\/ *<reference +(lib="dom"|types="node").*?\n/gm, | |
| 155 | // replace with same number of characters to avoid breaking source maps | |
| 156 | (match) => ' '.repeat(match.length - 1) + '\n', | |
| 157 | ); | |
| 158 | | |
| 159 | if (transformed !== code) { | |
| 160 | await fs.promises.writeFile(file, transformed, 'utf8'); | |
| 161 | console.error(`wrote ${path.relative(process.cwd(), file)}`); | |
| 162 | } | |
| 163 | } | |
| 164 | } | |
| 165 | postprocess(); |