fix: return same parser when babel options are the same

jedwards1211 · jedwards1211 · commit 602ff4b71235 · 2022-09-10T18:07:48.000-05:00
diff --git a/package.json b/package.json
@@ -85,6 +85,7 @@
     "@babel/plugin-proposal-nullish-coalescing-operator": "^7.12.1",
     "@babel/plugin-proposal-object-rest-spread": "^7.12.1",
     "@babel/plugin-proposal-optional-chaining": "^7.12.7",
+    "@babel/plugin-proposal-pipeline-operator": "^7.18.9",
     "@babel/plugin-syntax-dynamic-import": "^7.0.0",
     "@babel/plugin-transform-runtime": "^7.12.10",
     "@babel/preset-env": "^7.12.11",
diff --git a/src/index.ts b/src/index.ts
@@ -144,12 +144,48 @@ const resolve: (
 ) => Promise<string> = promisify(_resolve as any)
 
 const requiredPaths: string[] = []
-const syncCache: Map<string, Parser> = new Map()
-const asyncCache: Map<string, Promise<Parser>> = new Map()
+
+class Cache<K, V> {
+  syncCache: Map<K, V> = new Map()
+  asyncCache: Map<K, Promise<V>> = new Map()
+
+  getSync(key: K, fetch: () => V): V {
+    let result = this.syncCache.get(key)
+    if (!result) {
+      result = fetch()
+      this.syncCache.set(key, result)
+      this.asyncCache.set(key, Promise.resolve(result))
+    }
+    return result
+  }
+
+  getAsync(key: K, fetch: () => Promise<V>): Promise<V> {
+    let result = this.asyncCache.get(key)
+    if (!result) {
+      result = fetch()
+      this.asyncCache.set(key, result)
+      result.then((value) => {
+        // check if cache was cleared before this point
+        if (this.asyncCache.get(key) === result) {
+          this.syncCache.set(key, value)
+        }
+      })
+    }
+    return result
+  }
+
+  clear() {
+    this.syncCache.clear()
+    this.asyncCache.clear()
+  }
+}
+
+const dirParserCache = new Cache<string, Parser>()
+const babelrcParserCache = new Cache<string, Parser>()
 
 export function clearCache(): void {
-  syncCache.clear()
-  asyncCache.clear()
+  dirParserCache.clear()
+  babelrcParserCache.clear()
   for (const path of requiredPaths) {
     delete require.cache[path]
   }
@@ -170,13 +206,10 @@ function createParserFromConfig(babelParser: BabelParser, config: any): Parser {
 }
 
 export function getParserSync(file: string, options?: ParserOptions): Parser {
-  let result
   const parentDir = Path.dirname(file)
   const extname = Path.extname(file)
   const cacheKey = `${parentDir}${Path.delimiter}${extname}`
-  result = syncCache.get(cacheKey)
-
-  if (!result) {
+  const parser = dirParserCache.getSync(cacheKey, () => {
     try {
       const babelPath = _resolve.sync('@babel/core', {
         basedir: parentDir,
@@ -192,73 +225,85 @@ export function getParserSync(file: string, options?: ParserOptions): Parser {
       const parser = require(parserPath)
       requiredPaths.push(parserPath)
 
-      const config = babel.loadOptionsSync({
+      const loadOpts = {
         filename: file,
         cwd: Path.dirname(file),
         rootMode: 'upward-optional',
-      })
-      result = createParserFromConfig(parser, config)
+      }
+      const partial = babel.loadPartialConfigSync(loadOpts)
+      const babelrc = partial.babelrc || partial.config
+      const getParser = () => {
+        const config = babel.loadOptionsSync(loadOpts)
+        return createParserFromConfig(parser, config)
+      }
+      return babelrc
+        ? babelrcParserCache.getSync(
+            JSON.stringify([babelrc, extname]),
+            getParser
+          )
+        : getParser()
     } catch (error) {
-      result =
-        extname === '.tsx' ? tsxParser : extname === '.ts' ? tsParser : jsParser
+      return extname === '.tsx'
+        ? tsxParser
+        : extname === '.ts'
+        ? tsParser
+        : jsParser
     }
-    syncCache.set(cacheKey, result)
-    asyncCache.set(cacheKey, Promise.resolve(result))
-  }
-  return !options || isEmpty(options) ? result : result.bindParserOpts(options)
+  })
+  return !options || isEmpty(options) ? parser : parser.bindParserOpts(options)
 }
 
 export async function getParserAsync(
   file: string,
   options?: ParserOptions
 ): Promise<Parser> {
-  let promise
-  if (/\.ts$/.test(file)) promise = Promise.resolve(tsParser)
-  else if (/\.tsx$/.test(file)) promise = Promise.resolve(tsxParser)
-  else {
-    const parentDir = Path.dirname(file)
-    const extname = Path.extname(file)
-    const cacheKey = `${parentDir}${Path.delimiter}${extname}`
-
-    promise = asyncCache.get(cacheKey)
+  const parentDir = Path.dirname(file)
+  const extname = Path.extname(file)
+  const cacheKey = `${parentDir}${Path.delimiter}${extname}`
 
-    if (!promise) {
-      promise = (async (): Promise<Parser> => {
-        let result
-        try {
-          const babelPath = await resolve('@babel/core', {
-            basedir: parentDir,
-          })
-          const babel = await import(babelPath)
-          requiredPaths.push(babelPath)
+  const parser = await dirParserCache.getAsync(
+    cacheKey,
+    async (): Promise<Parser> => {
+      try {
+        const babelPath = await resolve('@babel/core', {
+          basedir: parentDir,
+        })
+        const babel = await import(babelPath)
+        requiredPaths.push(babelPath)
 
-          const parserPath = await resolve('@babel/parser', {
-            basedir: parentDir,
-          })
-          const parser = await import(parserPath)
-          requiredPaths.push(parserPath)
+        const parserPath = await resolve('@babel/parser', {
+          basedir: parentDir,
+        })
+        const parser = await import(parserPath)
+        requiredPaths.push(parserPath)
 
-          const config = await babel.loadOptionsAsync({
-            filename: file,
-            cwd: parentDir,
-          })
-          result = createParserFromConfig(parser, config)
-        } catch (error) {
-          result =
-            extname === '.tsx'
-              ? tsxParser
-              : extname === '.ts'
-              ? tsParser
-              : jsParser
+        const loadOpts = {
+          filename: file,
+          cwd: parentDir,
+          rootMode: 'upward-optional',
+        }
+        const partial = await babel.loadPartialConfigAsync(loadOpts)
+        const babelrc = partial.babelrc || partial.config
+        const getParser = async (): Promise<Parser> => {
+          const config = await babel.loadOptionsAsync(loadOpts)
+          return createParserFromConfig(parser, config)
         }
-        syncCache.set(cacheKey, result)
-        return result
-      })()
-      asyncCache.set(cacheKey, promise)
+        return babelrc
+          ? await babelrcParserCache.getAsync(
+              JSON.stringify([babelrc, extname]),
+              getParser
+            )
+          : await getParser()
+      } catch (error) {
+        return extname === '.tsx'
+          ? tsxParser
+          : extname === '.ts'
+          ? tsParser
+          : jsParser
+      }
     }
-  }
-  const result = await promise
-  return !options || isEmpty(options) ? result : result.bindParserOpts(options)
+  )
+  return !options || isEmpty(options) ? parser : parser.bindParserOpts(options)
 }
 
 export function parseSync(
diff --git a/test/index.spec.ts b/test/index.spec.ts
@@ -1,13 +1,51 @@
 /* eslint-env mocha */
 
 import * as Path from 'path'
-import { parseSync, parseAsync, getParserSync, clearCache } from '../src'
+import {
+  parseSync,
+  parseAsync,
+  getParserSync,
+  clearCache,
+  getParserAsync,
+  jsParser,
+  tsParser,
+  tsxParser,
+} from '../src'
 import fs from 'fs-extra'
 import { expect } from 'chai'
 import os from 'os'
 
 const fixturesDir = Path.resolve(__dirname, 'fixtures')
 
+describe(`getParserSync`, function () {
+  this.timeout(10000)
+
+  it(`returns same parser when babel config is the same`, async function () {
+    expect(getParserSync(Path.join(__dirname, 'index.spec.ts'))).to.equal(
+      getParserSync(Path.resolve(__dirname, '..', 'src', 'index.ts'))
+    )
+    expect(getParserSync(Path.join(__dirname, 'index.spec.ts'))).not.to.equal(
+      tsParser
+    )
+    expect(getParserSync(Path.join(__dirname, 'index.spec.ts'))).not.to.equal(
+      tsxParser
+    )
+    expect(getParserSync(Path.join(__dirname, 'index.spec.ts'))).not.to.equal(
+      getParserSync(Path.resolve(__dirname, 'configure.js'))
+    )
+    expect(getParserSync(Path.join(__dirname, 'configure.js'))).not.to.equal(
+      jsParser
+    )
+    expect(getParserSync(Path.join(__dirname, 'index.spec.ts'))).not.to.equal(
+      getParserSync(Path.resolve(__dirname, '..', 'src', 'index.js.flow'))
+    )
+    expect(getParserSync(Path.join(__dirname, 'index.spec.ts'))).not.to.equal(
+      getParserSync(
+        Path.resolve(__dirname, 'fixtures', 'babelPipeline', 'test.ts')
+      )
+    )
+  })
+})
 describe('parseSync', function () {
   this.timeout(10000)
 
@@ -75,6 +113,45 @@ describe('parseSync', function () {
     ).to.exist
   })
 })
+describe(`getParserAsync`, function () {
+  this.timeout(10000)
+
+  it(`returns same parser when babel config is the same`, async function () {
+    expect(
+      await getParserAsync(Path.join(__dirname, 'index.spec.ts'))
+    ).to.equal(
+      await getParserAsync(Path.resolve(__dirname, '..', 'src', 'index.ts'))
+    )
+    expect(
+      await getParserAsync(Path.join(__dirname, 'index.spec.ts'))
+    ).not.to.equal(tsParser)
+    expect(
+      await getParserAsync(Path.join(__dirname, 'index.spec.ts'))
+    ).not.to.equal(tsxParser)
+    expect(
+      await getParserAsync(Path.join(__dirname, 'index.spec.ts'))
+    ).not.to.equal(
+      await getParserAsync(Path.resolve(__dirname, 'configure.js'))
+    )
+    expect(
+      await getParserAsync(Path.join(__dirname, 'configure.js'))
+    ).not.to.equal(jsParser)
+    expect(
+      await getParserAsync(Path.join(__dirname, 'index.spec.ts'))
+    ).not.to.equal(
+      await getParserAsync(
+        Path.resolve(__dirname, '..', 'src', 'index.js.flow')
+      )
+    )
+    expect(
+      await getParserAsync(Path.join(__dirname, 'index.spec.ts'))
+    ).not.to.equal(
+      await getParserAsync(
+        Path.resolve(__dirname, 'fixtures', 'babelPipeline', 'test.ts')
+      )
+    )
+  })
+})
 describe(`parseAsync`, function () {
   this.timeout(10000)
 
diff --git a/yarn.lock b/yarn.lock
@@ -222,6 +222,11 @@
   resolved "https://registry.npmjs.org/@babel/helper-plugin-utils/-/helper-plugin-utils-7.13.0.tgz#806526ce125aed03373bc416a828321e3a6a33af"
   integrity sha512-ZPafIPSwzUlAoWT8DKs1W2VyF2gOWthGd5NGFMsBcMMol+ZhK+EQY/e6V96poa6PA/Bh+C9plWN0hXO1uB8AfQ==
 
+"@babel/helper-plugin-utils@^7.18.6", "@babel/helper-plugin-utils@^7.18.9":
+  version "7.19.0"
+  resolved "https://registry.yarnpkg.com/@babel/helper-plugin-utils/-/helper-plugin-utils-7.19.0.tgz#4796bb14961521f0f8715990bee2fb6e51ce21bf"
+  integrity sha512-40Ryx7I8mT+0gaNxm8JGTZFUITNqdLAgdg0hXzeVZxVD6nFsdhQvip6v8dqkRHzsz1VFpFAaOCHNn0vKBL7Czw==
+
 "@babel/helper-remap-async-to-generator@^7.12.13":
   version "7.12.13"
   resolved "https://registry.npmjs.org/@babel/helper-remap-async-to-generator/-/helper-remap-async-to-generator-7.12.13.tgz#170365f4140e2d20e5c88f8ba23c24468c296878"
@@ -429,6 +434,14 @@
     "@babel/helper-skip-transparent-expression-wrappers" "^7.12.1"
     "@babel/plugin-syntax-optional-chaining" "^7.8.0"
 
+"@babel/plugin-proposal-pipeline-operator@^7.18.9":
+  version "7.18.9"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-pipeline-operator/-/plugin-proposal-pipeline-operator-7.18.9.tgz#66a60666efd9c29c7ec4d3e2ccb38f9d97994237"
+  integrity sha512-Pc33e6m8f4MJhRXVCUwiKZNtEm+W2CUPHIL0lyJNtkp+w6d75CLw3gsBKQ81VAMUgT9jVPIEU8gwJ5nJgmJ1Ag==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.18.9"
+    "@babel/plugin-syntax-pipeline-operator" "^7.18.6"
+
 "@babel/plugin-proposal-private-methods@^7.12.13":
   version "7.12.13"
   resolved "https://registry.npmjs.org/@babel/plugin-proposal-private-methods/-/plugin-proposal-private-methods-7.12.13.tgz#ea78a12554d784ecf7fc55950b752d469d9c4a71"
@@ -543,6 +556,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.8.0"
 
+"@babel/plugin-syntax-pipeline-operator@^7.18.6":
+  version "7.18.6"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-pipeline-operator/-/plugin-syntax-pipeline-operator-7.18.6.tgz#daa44d460bba23478c329a0e8bbee433a681fd43"
+  integrity sha512-pFtIdQomJtkTHWcNsGXhjJ5YUkL+AxJnP4G+Ol85UO6uT2fpHTPYLLE5bBeRA9cxf25qa/VKsJ3Fi67Gyqe3rA==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.18.6"
+
 "@babel/plugin-syntax-top-level-await@^7.12.13":
   version "7.12.13"
   resolved "https://registry.npmjs.org/@babel/plugin-syntax-top-level-await/-/plugin-syntax-top-level-await-7.12.13.tgz#c5f0fa6e249f5b739727f923540cf7a806130178"
