feat: adding support for child lookups

Author: martinheidegger

index.ts

@@ -3,6 +3,7 @@ import { spawn } from 'child_process'
 import { mkdir, readFile, writeFile, stat, utimes } from 'fs/promises'
 import dbg from 'debug'
 import * as path from 'path'
+import { getMatcher, normalize } from './util'
 
 const debug = dbg('@tradle/lambda-plugins')
 
@@ -199,49 +200,24 @@ async function assertInstalled (plugins: FNOrResult<string[]>, { tmpDir, maxAge
   }
 }
 
-interface Cause {
-  useImport: boolean
-  cause: string
-}
-
-const CAUSE_FALLBACK: Cause = { cause: 'require', useImport: false }
-const CAUSE_TYPE: Cause = { cause: 'import because of type=module', useImport: true }
-const CAUSE_MODULE: Cause = { cause: 'import because of a defined module', useImport: true }
-const CAUSE_DOT_EXPORT: Cause = { cause: 'import because of exports["."]', useImport: true }
-const CAUSE_DOT_ANY: Cause = { cause: 'import because of exports["./*"]', useImport: true }
-
-function fuzzyChooseImport (pkg: any): Cause {
-  if (pkg.type === 'module') return CAUSE_TYPE
-  if (pkg.module !== undefined) return CAUSE_MODULE
-  if (typeof pkg.exports === 'object' && pkg.exports !== null) {
-    if (pkg.exports['.']?.import !== undefined) {
-      return CAUSE_DOT_EXPORT
-    }
-    if (pkg.exports['./*']?.import !== undefined) {
-      return CAUSE_DOT_ANY
-    }
-  }
-  return CAUSE_FALLBACK
-}
-
-async function loadData (name: string, depPath: string, pkg: any): Promise<any> {
-  const { cause, useImport } = fuzzyChooseImport(pkg)
-  debug('Loading package for %s from %s (%s)', name, depPath, cause)
-  return useImport ? await import(depPath) : require(depPath)
-}
-
 async function loadPackage (name: string, depPath: string): Promise<any> {
   const pkgPath = path.join(depPath, 'package.json')
-  debug('Loading package.json for %s from %s', name, pkgPath)
-  const data = await readFile(pkgPath, 'utf-8')
-  return JSON.parse(data)
+  let raw = '{}'
+  try {
+    raw = await readFile(pkgPath, 'utf-8')
+    debug('Using package.json for %s from %s', name, pkgPath)
+  } catch (err) {
+    // Package json is optional
+    debug('No package.json found at %s, using regular lookup', pkgPath)
+  }
+  return JSON.parse(raw)
 }
 
 export class Plugin {
   readonly name: string
   readonly path: string
 
-  #data: Promise<any> | undefined
+  #data: { [child: string]: Promise<any> } | undefined
   #pkg: Promise<any> | undefined
 
   constructor (name: string, path: string) {
@@ -259,15 +235,29 @@ export class Plugin {
     return pkg
   }
 
-  /* eslint-disable-next-line @typescript-eslint/promise-function-async */
-  data (opts?: { force?: boolean }): Promise<any> {
-    let data = this.#data
-    if (data === undefined || opts?.force !== true) {
-      /* eslint-disable-next-line @typescript-eslint/promise-function-async */
-      data = this.package(opts).then(pkg => loadData(this.name, this.path, pkg))
-      this.#data = data
+  async #loadData (child: string, force: boolean): Promise<any> {
+    const pkg = await this.package({ force })
+    const matcher = getMatcher(this.path, pkg)
+    const mjs = matcher(child, 'module')
+    /* eslint-disable-next-line @typescript-eslint/prefer-optional-chain */
+    if (mjs !== undefined && mjs.location !== null) {
+      debug('Importing package for %s from %s (%s)', this.name, mjs.location, mjs.cause)
+      return await import(mjs.location)
     }
-    return data
+    const cjs = matcher(child, 'commonjs')
+    /* eslint-disable-next-line @typescript-eslint/prefer-optional-chain */
+    if (cjs !== undefined && cjs.location !== null) {
+      debug('Requiring package for %s from %s (%s)', this.name, cjs.location, cjs.cause)
+      return require(cjs.location)
+    }
+    throw new Error(`Can not require or import a package for ${this.name} at ${this.path}`)
+  }
+
+  /* eslint-disable-next-line @typescript-eslint/promise-function-async */
+  data (opts?: { force?: boolean, child?: string }): Promise<any> {
+    const all = this.#data ?? (this.#data = {})
+    const child = normalize(opts?.child)
+    return all[child] ?? (all[child] = this.#loadData(child, opts?.force ?? false))
   }
 }
 

package.json

@@ -7,8 +7,9 @@
   "bin": "./bin/lambda-plugins",
   "scripts": {
     "prepare": "npm run build",
-    "build": "tsc && tsc -p tsconfig.cjs.json",
+    "build": "tsc -p tsconfig.mjs.json && tsc -p tsconfig.cjs.json",
     "lint": "ts-standard",
+    "unit": "c8 ts-node test/*.test.ts",
     "test": "npm run lint"
   },
   "ts-standard": {
@@ -21,6 +22,9 @@
   "devDependencies": {
     "@types/debug": "^4.1.7",
     "@types/node": "^17.0.16",
+    "c8": "^7.11.0",
+    "fresh-tape": "^5.5.0",
+    "ts-node": "^10.5.0",
     "ts-standard": "^11.0.0",
     "typescript": "^4.4.4"
   },

test/util.test.ts

@@ -0,0 +1,84 @@
+import { createMatcher, getMatcher } from '../util'
+import * as test from 'fresh-tape'
+
+test('repeat, on-demand matcher', async t => {
+  const pkg = { main: 'index.js' }
+  const matcher = getMatcher('/root', pkg)
+  t.deepEqual(matcher('.', 'commonjs'), { cause: '.main', location: '/root/index.js' })
+  t.equal(getMatcher('/root', pkg), matcher)
+})
+test('simple main', async t => {
+  const match = createMatcher('/root', { main: './test.js' })
+  for (const input of [
+    '',
+    '.',
+    './'
+  ]) {
+    t.deepEqual(match(input, 'commonjs'), { cause: '.main', location: '/root/test.js' })
+  }
+  t.equal(match('', 'module'), undefined)
+})
+test('export override string', async t => {
+  const a = createMatcher('/root', { main: 'a.js', exports: './b.js' })
+  t.deepEqual(a('', 'commonjs'), { cause: '.exports[\'.\']', location: '/root/b.js' })
+  t.deepEqual(a('', 'module'), { cause: '.exports[\'.\']', location: '/root/b.js' })
+})
+test('export override object', async t => {
+  const a = createMatcher('/root', { main: 'a.js', exports: { import: './b.js', require: './c.js' } })
+  t.deepEqual(a('', 'commonjs'), { cause: '.exports[\'.\'].require', location: '/root/c.js' })
+  t.deepEqual(a('', 'module'), { cause: '.exports[\'.\'].import', location: '/root/b.js' })
+})
+test('export deep override', async t => {
+  const match = createMatcher('/root', {
+    main: 'a.js',
+    exports: {
+      '.': { require: './b.js', import: './c.js' },
+      './c-a': { require: './d.js', import: './e.js' },
+      './c-b': { default: './f.js' },
+      './c-c': { node: './g.js', require: './h.js', default: './i.js' }
+    }
+  })
+  t.deepEqual(match('c-a', 'commonjs'), { cause: '.exports[\'./c-a\'].require', location: '/root/d.js' })
+  t.equals(match('c-a.js', 'commonjs'), undefined)
+  t.deepEqual(match('c-a', 'module'), { cause: '.exports[\'./c-a\'].import', location: '/root/e.js' })
+  t.deepEqual(match('c-b', 'commonjs'), { cause: '.exports[\'./c-b\'].default', location: '/root/f.js' })
+  t.deepEqual(match('c-b', 'module'), { cause: '.exports[\'./c-b\'].default', location: '/root/f.js' })
+  t.deepEqual(match('c-c', 'commonjs'), { cause: '.exports[\'./c-c\'].node', location: '/root/g.js' })
+  t.deepEqual(match('c-c', 'module'), { cause: '.exports[\'./c-c\'].default', location: '/root/i.js' })
+})
+test('pattern', async t => {
+  const match = createMatcher('/root', {
+    main: 'a.js',
+    exports: {
+      './foo/*': null,
+      './bar/*': { require: null },
+      '.': { require: './b.js', import: './c.js' },
+      './bak/*.ts': { require: './cjs/*.js' },
+      './*': { require: './cjs/*.js', import: './mjs/*' }
+    }
+  })
+  t.deepEqual(match('c-a', 'commonjs'), { cause: '.exports[\'./*\'].require', location: '/root/cjs/c-a.js' })
+  t.deepEqual(match('foo/c-a', 'commonjs'), { cause: '.exports[\'./foo/*\']', location: null })
+  t.deepEqual(match('bar/c-a', 'commonjs'), { cause: '.exports[\'./bar/*\'].require', location: null })
+  t.deepEqual(match('baz/c-a', 'module'), { cause: '.exports[\'./*\'].import', location: '/root/mjs/baz/c-a' })
+  t.deepEqual(match('bak/d.ts', 'commonjs'), { cause: '.exports[\'./bak/*.ts\'].require', location: '/root/cjs/d.js' })
+})
+test('deep require', async t => {
+  const deep = createMatcher('/root', { exports: { './test': './a.js' } })
+  t.deepEqual(deep('test', 'commonjs'), { cause: '.exports[\'./test\']', location: '/root/a.js' })
+})
+test('main and type=module', async t => {
+  const match = createMatcher('/root', { main: './test.js', type: 'module' })
+  t.equal(match('', 'commonjs'), undefined)
+  t.deepEqual(match('', 'module'), { cause: '.main and .type=module', location: '/root/test.js' })
+})
+test('module', async t => {
+  const match = createMatcher('/root', { main: './a.cjs', module: 'b.mjs' })
+  t.deepEqual(match('', 'commonjs'), { cause: '.main', location: '/root/a.cjs' })
+  t.deepEqual(match('', 'module'), { cause: '.module', location: '/root/b.mjs' })
+})
+test.skip('empty match', async t => {
+  const match = createMatcher('/root', {})
+  t.deepEqual(match('', 'commonjs'), { cause: 'fs', location: '/root/indexs.js' })
+  t.equal(match('', 'module'), undefined)
+})

tsconfig.cjs.json

@@ -1,7 +1,6 @@
 {
     "extends": "./tsconfig.json",
     "compilerOptions": {
-        "module": "commonjs",
         "outDir": "cjs"
     }
 }

tsconfig.json

@@ -5,13 +5,13 @@
     "strictNullChecks": true,
     "sourceMap": true,
     "strict": true,
-    "module": "es2020",
+    "module": "commonjs",
     "strictFunctionTypes": true,
     "forceConsistentCasingInFileNames": true,
     "target": "ES2017",
     "moduleResolution": "node",
     "declaration": true,
     "lib": ["es2018"],
-    "outDir": "./mjs",
+    "outDir": ".work",
   }
 }

tsconfig.mjs.json

@@ -0,0 +1,7 @@
+{
+    "extends": "./tsconfig.json",
+    "compilerOptions": {
+        "module": "es2020",
+        "outDir": "mjs"
+    }
+}