Add jest-serializer module (#5609)

Author: mjesun

packages/jest-haste-map/package.json

@@ -11,6 +11,7 @@
     "fb-watchman": "^2.0.0",
     "graceful-fs": "^4.1.11",
     "jest-docblock": "^22.2.2",
+    "jest-serializer": "^22.3.0",
     "jest-worker": "^22.2.2",
     "micromatch": "^2.3.11",
     "sane": "^2.0.0"

packages/jest-haste-map/src/index.js

@@ -12,7 +12,6 @@ import {version as VERSION} from '../package.json';
 import {worker} from './worker';
 import crypto from 'crypto';
 import EventEmitter from 'events';
-import fs from 'graceful-fs';
 import getMockName from './get_mock_name';
 import getPlatformExtension from './lib/get_platform_extension';
 // eslint-disable-next-line import/no-duplicates
@@ -25,7 +24,7 @@ import normalizePathSep from './lib/normalize_path_sep';
 import os from 'os';
 import path from 'path';
 import sane from 'sane';
-import v8 from 'v8';
+import serializer from 'jest-serializer';
 // eslint-disable-next-line import/default
 import watchmanCrawl from './crawlers/watchman';
 import WatchmanWatcher from './lib/watchman_watcher';
@@ -290,21 +289,14 @@ class HasteMap extends EventEmitter {
    * 1. read data from the cache or create an empty structure.
    */
   read(): InternalHasteMap {
-    if (v8.deserialize) {
-      // This may throw. `_buildFileMap` will catch it and create a new map.
-      const {version, hasteMap} = v8.deserialize(
-        fs.readFileSync(this._cachePath),
-      );
-      if (version !== process.versions.v8) {
-        throw new Error('jest-haste-map: v8 versions do not match.');
-      }
-      return removePrototypes(hasteMap);
-    } else {
-      const hasteMap = (JSON.parse(
-        fs.readFileSync(this._cachePath, 'utf8'),
-      ): InternalHasteMap);
-      return removePrototypes(hasteMap);
+    // This may throw. `_buildFileMap` will catch it and create a new map.
+    const hasteMap: InternalHasteMap = serializer.readFileSync(this._cachePath);
+
+    for (const key in hasteMap) {
+      Object.setPrototypeOf(hasteMap[key], null);
     }
+
+    return hasteMap;
   }
 
   readModuleMap(): ModuleMap {
@@ -534,17 +526,7 @@ class HasteMap extends EventEmitter {
    * 4. serialize the new `HasteMap` in a cache file.
    */
   _persist(hasteMap: InternalHasteMap) {
-    if (v8.serialize) {
-      fs.writeFileSync(
-        this._cachePath,
-        v8.serialize({
-          hasteMap,
-          version: process.versions.v8,
-        }),
-      );
-    } else {
-      fs.writeFileSync(this._cachePath, JSON.stringify(hasteMap), 'utf8');
-    }
+    serializer.writeFileSync(this._cachePath, hasteMap);
   }
 
   /**
@@ -913,12 +895,6 @@ class HasteMap extends EventEmitter {
 }
 
 const copy = object => Object.assign(Object.create(null), object);
-const removePrototypes = object => {
-  for (const key in object) {
-    Object.setPrototypeOf(object[key], null);
-  }
-  return object;
-};
 
 HasteMap.H = H;
 HasteMap.ModuleMap = HasteModuleMap;

packages/jest-serializer/.npmignore

@@ -0,0 +1,3 @@
+**/__mocks__/**
+**/__tests__/**
+src

packages/jest-serializer/README.md

@@ -0,0 +1,54 @@
+# jest-serializer
+
+Module for serializing and deserializing object into memory and disk. By
+default, the `v8` implementations are used, but if not present, it defaults to
+`JSON` implementation. Both serializers have the advantage of being able to
+serialize `Map`, `Set`, `undefined`, `NaN`, etc, although the JSON one does it
+through a replacer/reviver.
+
+## Install
+
+```sh
+$ yarn add jest-serializer
+```
+
+## API
+
+Three kinds of API groups are exposed:
+
+### In-memory serialization: `serialize` and `deserialize`
+
+This set of functions take or return a `Buffer`. All the process happens in
+memory. This is useful when willing to transfer over HTTP, TCP or via UNIX
+pipes.
+
+```javascript
+import {serialize, deserialize} from 'jest-serializer';
+
+const myObject = {
+  foo: 'bar',
+  baz: [0, true, '2', [], {}],
+};
+
+const buffer = serialize(myObject);
+const myCopyObject = deserialize(buffer);
+```
+
+### Synchronous persistent filesystem: `readFileSync` and `writeFileSync`
+
+This set of functions allow to send to disk a serialization result and retrieve
+it back, in a synchronous way. It mimics the `fs` API so it looks familiar.
+
+```javascript
+import {readFileSync, writeFileSync} from 'jest-serializer';
+
+const myObject = {
+  foo: 'bar',
+  baz: [0, true, '2', [], {}],
+};
+
+const myFile = '/tmp/obj';
+
+writeFileSync(myFile, myObject);
+const myCopyObject = readFileSync(myFile);
+```

packages/jest-serializer/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "jest-serializer",
+  "version": "22.3.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/facebook/jest.git"
+  },
+  "license": "MIT",
+  "main": "build/index.js"
+}

packages/jest-serializer/src/__tests__/index.test.js

@@ -0,0 +1,93 @@
+/**
+ * Copyright (c) 2018-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+import prettyFormat from 'pretty-format';
+
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+import v8 from 'v8';
+
+import serializer from '..';
+
+const v8s = [
+  {
+    deserialize: v8.deserialize,
+    serialize: v8.serialize,
+  },
+  {
+    deserialize: undefined,
+    serialize: undefined,
+  },
+];
+
+const objs = [
+  3,
+  null,
+  [0, true, '2', [3.14, {}, null]],
+  {key1: 'foo', key2: 'bar', key3: {array: [null, {}]}},
+  {minusInf: -Infinity, nan: NaN, plusInf: +Infinity},
+  {date: new Date(1234567890), re: /foo/gi},
+  {map: new Map([[NaN, 4], [undefined, 'm']]), set: new Set([undefined, NaN])},
+  {buf: Buffer.from([0, 255, 127])},
+];
+
+const file = path.join(os.tmpdir(), '__jest-serialize-test__');
+
+afterEach(() => {
+  try {
+    fs.unlinkSync(file);
+  } catch (err) {
+    // Do nothing if file does not exist.
+  }
+});
+
+// We execute the same suite of tests over multiple objects ("objs") and over
+// multiple mocks of the V8 object ("v8s") so that we verify that all possible
+// encodings and cases work.
+v8s.forEach((mockV8, i) => {
+  describe('Using V8 implementation ' + i, () => {
+    beforeEach(() => {
+      v8.serialize = mockV8.serialize;
+      v8.deserialize = mockV8.deserialize;
+    });
+
+    it('throws the error with an invalid serialization', () => {
+      // No chance this is a valid serialization, neither in JSON nor V8.
+      const invalidBuffer = Buffer.from([0, 85, 170, 255]);
+
+      fs.writeFileSync(file, invalidBuffer);
+
+      expect(() => serializer.deserialize(invalidBuffer)).toThrow();
+      expect(() => serializer.readFileSync(file)).toThrow();
+    });
+
+    objs.forEach((obj, i) => {
+      describe('Object ' + i, () => {
+        it('serializes/deserializes in memory', () => {
+          const buf = serializer.serialize(obj);
+
+          expect(buf).toBeInstanceOf(Buffer);
+
+          expect(prettyFormat(serializer.deserialize(buf))).toEqual(
+            prettyFormat(obj),
+          );
+        });
+
+        it('serializes/deserializes in disk', () => {
+          serializer.writeFileSync(file, obj);
+
+          expect(prettyFormat(serializer.readFileSync(file))).toEqual(
+            prettyFormat(obj),
+          );
+        });
+      });
+    });
+  });
+});