Unescape serialized snapshots for diffing (jestjs#2852)

* Unescape serialized snapshots for diffing

* Normalize \r same way as \r\n by @rubenmoya

* Don't unescape regex for now

Author: thymikee

packages/jest-snapshot/src/State.js

@@ -19,6 +19,7 @@ const {
   keyToTestName,
   serialize,
   testNameToKey,
+  unescape,
 } = require('./utils');
 const fileExists = require('jest-file-exists');
 const fs = require('fs');
@@ -158,9 +159,9 @@ class SnapshotState {
       if (!pass) {
         this.unmatched++;
         return {
-          actual: receivedSerialized,
+          actual: unescape(receivedSerialized),
           count,
-          expected,
+          expected: unescape(expected),
           pass: false,
         };
       } else {

packages/jest-snapshot/src/__tests__/utils-test.js

@@ -41,7 +41,7 @@ test('getSnapshotPath()', () => {
   );
 });
 
-test('saveSnapshotFile()', () => {
+test('saveSnapshotFile() works with \r\n', () => {
   const filename = path.join(__dirname, 'remove-newlines.snap');
   const data = {
     myKey: '<div>\r\n</div>',
@@ -52,6 +52,17 @@ test('saveSnapshotFile()', () => {
     .toBeCalledWith(filename, 'exports[`myKey`] = `<div>\n</div>`;\n');
 });
 
+test('saveSnapshotFile() works with \r', () => {
+  const filename = path.join(__dirname, 'remove-newlines.snap');
+  const data = {
+    myKey: '<div>\r</div>',
+  };
+
+  saveSnapshotFile(data, filename);
+  expect(fs.writeFileSync)
+    .toBeCalledWith(filename, 'exports[`myKey`] = `<div>\n</div>`;\n');
+});
+
 test('escaping', () => {
   const filename = path.join(__dirname, 'escaping.snap');
   const data = '"\'\\';

packages/jest-snapshot/src/utils.js

@@ -66,6 +66,9 @@ const serialize = (data: any): string => {
   }));
 };
 
+const unescape = (data: any): string =>
+  data.replace(/\\(")/g, '$1'); // unescape double quotes
+
 const printBacktickString = (str: string) => {
   return '`' + str.replace(/`|\\|\${/g, '\\$&') + '`';
 };
@@ -77,7 +80,7 @@ const ensureDirectoryExists = (filePath: Path) => {
 };
 
 const normalizeNewlines =
-  string => string.replace(/\r\n/g, '\n');
+  string => string.replace(/\r\n|\r/g, '\n');
 
 const saveSnapshotFile = (
   snapshotData: {[key: string]: string},
@@ -102,4 +105,5 @@ module.exports = {
   saveSnapshotFile,
   serialize,
   testNameToKey,
+  unescape,
 };