feat: auto config preset (#30)

Co-authored-by: Pooya Parsa <pyapar@gmail.com>

.github/workflows/ci.yml

@@ -16,7 +16,8 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: 16
-          cache: 'yarn'
+          cache: "yarn"
       - run: yarn install
       - run: yarn lint
       - run: yarn build
+      - run: yarn test

.gitignore

@@ -6,3 +6,4 @@ coverage
 dist
 types
 .gen
+.nyc_output

package.json

@@ -20,7 +20,7 @@
     "unbuild": "jiti ./src/cli",
     "prepack": "yarn build",
     "release": "yarn test && standard-version && git push --follow-tags && npm publish",
-    "test": "yarn lint"
+    "test": "mocha -r jiti/register ./test/*.test.*"
   },
   "dependencies": {
     "@rollup/plugin-alias": "^3.1.8",
@@ -53,11 +53,15 @@
   },
   "devDependencies": {
     "@nuxtjs/eslint-config-typescript": "latest",
+    "@types/chai": "latest",
     "@types/mkdirp": "latest",
+    "@types/mocha": "latest",
     "@types/mri": "latest",
     "@types/node": "latest",
     "@types/rimraf": "latest",
+    "chai": "latest",
     "eslint": "latest",
+    "mocha": "latest",
     "standard-version": "latest"
   }
 }

src/auto.ts

@@ -0,0 +1,179 @@
+import { normalize, join } from 'pathe'
+import consola from 'consola'
+import chalk from 'chalk'
+import type { PackageJson } from 'pkg-types'
+import { listRecursively } from './utils'
+import { BuildEntry, definePreset, MkdistBuildEntry } from './types'
+
+type OutputDescriptor = { file: string, type?: 'esm' | 'cjs' }
+type InferEntriesResult = { entries: BuildEntry[], cjs?: boolean, dts?: boolean }
+
+export const autoPreset = definePreset(() => {
+  return {
+    hooks: {
+      'build:prepare' (ctx) {
+        // Disable auto if entries already provided of pkg not available
+        if (!ctx.pkg || ctx.options.entries.length) {
+          return
+        }
+        const sourceFiles = listRecursively(join(ctx.options.rootDir, 'src'))
+        const res = inferEntries(ctx.pkg, sourceFiles)
+        ctx.options.entries.push(...res.entries)
+        if (res.cjs) {
+          ctx.options.rollup.emitCJS = true
+        }
+        if (res.dts) {
+          ctx.options.declaration = res.dts
+        }
+        consola.info(
+          'Automatically detected entries:',
+          chalk.cyan(ctx.options.entries.map(e => chalk.bold(e.input.replace(ctx.options.rootDir + '/', '').replace(/\/$/, '/*'))).join(', ')),
+          chalk.gray(['esm', res.cjs && 'cjs', res.dts && 'dts'].filter(Boolean).map(tag => `[${tag}]`).join(' '))
+        )
+      }
+    }
+  }
+})
+
+/**
+ * @param {PackageJson} pkg The contents of a package.json file to serve as the source for inferred entries.
+ * @param {string | string[]} source The root directory of the project.
+ *   - if string, `<source>/src` will be scanned for possible source files.
+ *   - if an array of source files, these will be used directly instead of accessing fs.
+ */
+export function inferEntries (pkg: PackageJson, sourceFiles: string[]): InferEntriesResult {
+  // Come up with a list of all output files & their formats
+  const outputs: OutputDescriptor[] = extractExportFilenames(pkg.exports)
+
+  if (pkg.bin) {
+    const binaries = typeof pkg.bin === 'string' ? [pkg.bin] : Object.values(pkg.bin)
+    for (const file of binaries) {
+      outputs.push({ file })
+    }
+  }
+  if (pkg.main) {
+    outputs.push({ file: pkg.main })
+  }
+  if (pkg.module) {
+    outputs.push({ type: 'esm', file: pkg.module })
+  }
+  if (pkg.types || pkg.typings) {
+    outputs.push({ file: pkg.types || pkg.typings! })
+  }
+
+  // Try to detect output types
+  const isESMPkg = pkg.type === 'module'
+  for (const output of outputs.filter(o => !o.type)) {
+    const isJS = output.file.endsWith('.js')
+    if ((isESMPkg && isJS) || output.file.endsWith('.mjs')) {
+      output.type = 'esm'
+    } else if ((!isESMPkg && isJS) || output.file.endsWith('.cjs')) {
+      output.type = 'cjs'
+    }
+  }
+
+  let cjs = false
+  let dts = false
+
+  // Infer entries from package files
+  const entries: BuildEntry[] = []
+  for (const output of outputs) {
+    // Supported output file extensions are `.d.ts`, `.cjs` and `.mjs`
+    // But we support any file extension here in case user has extended rollup options
+    const outputSlug = output.file.replace(/(\*[^\\/]*|\.d\.ts|\.\w+)$/, '')
+    const isDir = outputSlug.endsWith('/')
+
+    // Skip top level directory
+    if (isDir && ['./', '/'].includes(outputSlug)) { continue }
+
+    const possiblePaths = getEntrypointPaths(outputSlug)
+    const input = possiblePaths.reduce<string | undefined>((source, d) => {
+      if (source) { return source }
+      const SOURCE_RE = new RegExp(`${d}${isDir ? '' : '\\.\\w+'}$`)
+      return sourceFiles.find(i => i.match(SOURCE_RE))?.replace(/(\.d\.ts|\.\w+)$/, '')
+    }, undefined)
+
+    if (!input) {
+      consola.warn(`could not infer entrypoint for \`${output.file}\``)
+      continue
+    }
+
+    if (output.type === 'cjs') {
+      cjs = true
+    }
+
+    const entry = entries.find(i => i.input === input) || entries[entries.push({ input }) - 1]
+
+    if (output.file.endsWith('.d.ts')) {
+      dts = true
+    }
+
+    if (isDir) {
+      entry.outDir = outputSlug
+      ;(entry as MkdistBuildEntry).format = output.type
+    }
+  }
+
+  return { entries, cjs, dts }
+}
+
+export function inferExportType (condition: string, previousConditions: string[] = [], filename = ''): 'esm' | 'cjs' {
+  if (filename) {
+    if (filename.endsWith('.d.ts')) {
+      return 'esm'
+    }
+    if (filename.endsWith('.mjs')) {
+      return 'esm'
+    }
+    if (filename.endsWith('.cjs')) {
+      return 'cjs'
+    }
+  }
+  switch (condition) {
+    case 'import':
+      return 'esm'
+    case 'require':
+      return 'cjs'
+    default: {
+      if (!previousConditions.length) {
+        // TODO: Check against type:module for default
+        return 'esm'
+      }
+      const [newCondition, ...rest] = previousConditions
+      return inferExportType(newCondition, rest, filename)
+    }
+  }
+}
+
+export function extractExportFilenames (exports: PackageJson['exports'], conditions: string[] = []): OutputDescriptor[] {
+  if (!exports) { return [] }
+  if (typeof exports === 'string') {
+    return [{ file: exports, type: 'esm' }]
+  }
+  return Object.entries(exports).flatMap(
+    ([condition, exports]) => typeof exports === 'string'
+      ? { file: exports, type: inferExportType(condition, conditions, exports) }
+      : extractExportFilenames(exports, [...conditions, condition])
+  )
+}
+
+export const getEntrypointPaths = (path: string) => {
+  const segments = normalize(path).split('/')
+  return segments.map((_, index) => segments.slice(index).join('/')).filter(Boolean)
+}
+
+export const getEntrypointFilenames = (path: string, supportedExtensions = ['.ts', '.mjs', '.cjs', '.js', '.json']) => {
+  if (path.startsWith('./')) { path = path.slice(2) }
+
+  const filenames = getEntrypointPaths(path).flatMap((path) => {
+    const basefile = path.replace(/\.\w+$/, '')
+    return [
+      basefile,
+      `${basefile}/index`
+    ]
+  })
+
+  filenames.push('index')
+
+  return filenames.flatMap(name => supportedExtensions.map(ext => `${name}${ext}`))
+}

src/build.ts

@@ -1,12 +1,13 @@
 import Module from 'module'
 import { resolve, basename } from 'pathe'
+import type { PackageJson } from 'pkg-types'
 import chalk from 'chalk'
 import consola from 'consola'
 import defu from 'defu'
 import { createHooks } from 'hookable'
 import prettyBytes from 'pretty-bytes'
 import mkdirp from 'mkdirp'
-import { dumpObject, rmdir, tryRequire } from './utils'
+import { dumpObject, rmdir, tryRequire, resolvePreset } from './utils'
 import type { BuildContext, BuildConfig, BuildOptions } from './types'
 import { validateDependencies } from './validate'
 import { rollupBuild } from './builder/rollup'
@@ -19,13 +20,10 @@ export async function build (rootDir: string, stub: boolean, inputConfig: BuildC
 
   // Read build.config and package.json
   const buildConfig: BuildConfig = tryRequire('./build.config', rootDir) || {}
-  const pkg = tryRequire('./package.json', rootDir)
+  const pkg: PackageJson & Record<'unbuild' | 'build', BuildConfig> = tryRequire('./package.json', rootDir)
 
   // Resolve preset
-  let preset = buildConfig.preset || pkg.unbuild?.preset || pkg.build?.preset || inputConfig.preset || {}
-  if (typeof preset === 'string') {
-    preset = tryRequire(preset, rootDir)
-  }
+  const preset = resolvePreset(buildConfig.preset || pkg.unbuild?.preset || pkg.build?.preset || inputConfig.preset || 'auto', rootDir)
 
   // Merge options
   const options = defu(buildConfig, pkg.unbuild || pkg.build, inputConfig, preset, <BuildOptions>{
@@ -40,7 +38,7 @@ export async function build (rootDir: string, stub: boolean, inputConfig: BuildC
     devDependencies: [],
     peerDependencies: [],
     rollup: {
-      emitCJS: true,
+      emitCJS: false,
       cjsBridge: false,
       inlineDependencies: false
     }
@@ -69,6 +67,9 @@ export async function build (rootDir: string, stub: boolean, inputConfig: BuildC
     ctx.hooks.addHooks(buildConfig.hooks)
   }
 
+  // Allow prepare and extending context
+  await ctx.hooks.callHook('build:prepare', ctx)
+
   // Normalize entries
   options.entries = options.entries.map(entry =>
     typeof entry === 'string' ? { input: entry } : entry

src/types.ts

@@ -1,3 +1,4 @@
+/* eslint-disable no-use-before-define */
 import type { PackageJson } from 'pkg-types'
 import type { Hookable } from 'hookable'
 import type { RollupOptions, RollupBuild } from 'rollup'
@@ -54,13 +55,15 @@ export interface BuildContext {
   pkg: PackageJson,
   buildEntries: { path: string, bytes?: number, exports?: string[], chunks?: string[] }[]
   usedImports: Set<string>
-  hooks: Hookable<BuildHooks> // eslint-disable-line no-use-before-define
+  hooks: Hookable<BuildHooks>
 }
 
+export type BuildPreset = BuildConfig | (() => BuildConfig)
+
 export interface BuildConfig extends Partial<Omit<BuildOptions, 'entries'>> {
   entries?: (BuildEntry | string)[]
-  preset?: string | BuildConfig
-  hooks?: Partial<BuildHooks> // eslint-disable-line no-use-before-define
+  preset?: string | BuildPreset
+  hooks?: Partial<BuildHooks>
 }
 
 export interface UntypedOutput { fileName: string, contents: string }
@@ -72,6 +75,7 @@ export interface UntypedOutputs {
   }
 
 export interface BuildHooks {
+  'build:prepare': (ctx: BuildContext) => void | Promise<void>
   'build:before': (ctx: BuildContext) => void | Promise<void>
   'build:done': (ctx: BuildContext) => void | Promise<void>
 
@@ -96,3 +100,7 @@ export interface BuildHooks {
 export function defineBuildConfig (config: BuildConfig): BuildConfig {
   return config
 }
+
+export function definePreset (preset: BuildPreset): BuildPreset {
+  return preset
+}

src/utils.ts

@@ -1,9 +1,12 @@
 import fsp from 'fs/promises'
 import { promisify } from 'util'
-import { dirname } from 'pathe'
+import { readdirSync, statSync } from 'fs'
+import { dirname, resolve } from 'pathe'
 import mkdirp from 'mkdirp'
 import _rimraf from 'rimraf'
 import jiti from 'jiti'
+import { autoPreset } from './auto'
+import type { BuildPreset, BuildConfig } from './types'
 
 export async function ensuredir (path: string) {
   await mkdirp(dirname(path))
@@ -33,6 +36,24 @@ export async function rmdir (dir: string) {
   await rimraf(dir)
 }
 
+export function listRecursively (path: string) {
+  const filenames = new Set<string>()
+  const walk = (path: string) => {
+    const files = readdirSync(path)
+    for (const file of files) {
+      const fullPath = resolve(path, file)
+      if (statSync(fullPath).isDirectory()) {
+        filenames.add(fullPath + '/')
+        walk(fullPath)
+      } else {
+        filenames.add(fullPath)
+      }
+    }
+  }
+  walk(path)
+  return Array.from(filenames)
+}
+
 export function tryRequire (id: string, rootDir: string = process.cwd()) {
   const _require = jiti(rootDir, { interopDefault: true })
   try {
@@ -56,3 +77,15 @@ export function tryResolve (id: string, rootDir: string = process.cwd()) {
     return id
   }
 }
+
+export function resolvePreset (preset: string | BuildPreset, rootDir: string): BuildConfig {
+  if (preset === 'auto') {
+    preset = autoPreset
+  } else if (typeof preset === 'string') {
+    preset = tryRequire(preset, rootDir) || {}
+  }
+  if (typeof preset === 'function') {
+    preset = preset()
+  }
+  return preset as BuildConfig
+}