jest-snapshot: Highlight substring differences when matcher fails, part 3

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - `[expect]` Highlight substring differences when matcher fails, part 1 ([#8448](https://github.com/facebook/jest/pull/8448))
 - `[expect]` Highlight substring differences when matcher fails, part 2 ([#8528](https://github.com/facebook/jest/pull/8528))
+- `[jest-snapshot]` Highlight substring differences when matcher fails, part 3 ([#8569](https://github.com/facebook/jest/pull/8569))
 - `[jest-cli]` Improve chai support (with detailed output, to match jest exceptions) ([#8454](https://github.com/facebook/jest/pull/8454))
 - `[*]` Manage the global timeout with `--testTimeout` command line argument. ([#8456](https://github.com/facebook/jest/pull/8456))
 - `[pretty-format]` Render custom displayName of memoized components

e2e/__tests__/__snapshots__/failures.test.ts.snap

@@ -790,11 +790,8 @@ FAIL __tests__/snapshot.test.js
 
     Snapshot name: \`failing snapshot 1\`
 
-    - Snapshot
-    + Received
-
-    - "bar"
-    + "foo"
+    Snapshot: "bar"
+    Received: "foo"
 
        9 | 
       10 | test('failing snapshot', () => {
@@ -819,11 +816,8 @@ FAIL __tests__/snapshotWithHint.test.js
 
     Snapshot name: \`failing snapshot with hint: descriptive hint 1\`
 
-    - Snapshot
-    + Received
-
-    - "bar"
-    + "foo"
+    Snapshot: "bar"
+    Received: "foo"
 
        9 | 
       10 | test('failing snapshot with hint', () => {

e2e/__tests__/__snapshots__/watchModeUpdateSnapshot.test.ts.snap

@@ -6,10 +6,8 @@ FAIL __tests__/bar.spec.js
   ● bar
     expect(received).toMatchSnapshot()
     Snapshot name: \`bar 1\`
-    - Snapshot
-    + Received
-    - "foo"
-    + "bar"
+    Snapshot: "foo"
+    Received: "bar"
       1 |
     > 2 |       test('bar', () => { expect('bar').toMatchSnapshot(); });
         |                                         ^

e2e/__tests__/toMatchSnapshot.test.ts

@@ -108,7 +108,7 @@ test('first snapshot fails, second passes', () => {
     writeFiles(TESTS_DIR, {[filename]: template([`'kiwi'`, `'banana'`])});
     const {stderr, status} = runJest(DIR, ['-w=1', '--ci=false', filename]);
     expect(stderr).toMatch('Snapshot name: `snapshots 1`');
-    expect(stderr).toMatch('- "apple"\n    + "kiwi"');
+    expect(stderr).toMatch('Snapshot: "apple"\n    Received: "kiwi"');
     expect(stderr).not.toMatch('1 obsolete snapshot found');
     expect(status).toBe(1);
   }

packages/jest-snapshot/package.json

@@ -15,6 +15,7 @@
     "chalk": "^2.0.1",
     "expect": "^24.8.0",
     "jest-diff": "^24.8.0",
+    "jest-get-type": "^24.8.0",
     "jest-matcher-utils": "^24.8.0",
     "jest-message-util": "^24.8.0",
     "jest-resolve": "^24.8.0",

packages/jest-snapshot/src/__tests__/__snapshots__/printDiffOrStringified.test.ts.snap

@@ -0,0 +1,185 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`empty string expected and received single line 1`] = `
+Snapshot: <g>""</>
+Received: <r>"single line string"</>
+`;
+
+exports[`empty string received and expected multi line 1`] = `
+Snapshot: <g>"multi</>
+<g>line</>
+<g>string"</>
+Received: <r>""</>
+`;
+
+exports[`escape backslash in multi line string 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<g>- Forward / slash<i> and b</i>ack \\ slash</>
+<r>+ Forward / slash</>
+<r>+ <i>B</i>ack \\ slash</>
+`;
+
+exports[`escape backslash in single line string 1`] = `
+Snapshot: <g>"<i>f</i>orward / slash and back \\\\ slash"</>
+Received: <r>"<i>F</i>orward / slash and back \\\\ slash"</>
+`;
+
+exports[`escape double quote marks in string 1`] = `
+Snapshot: <g>"What does \\"<i>oo</i>bleck\\" mean?"</>
+Received: <r>"What does \\"<i>ew</i>bleck\\" mean?"</>
+`;
+
+exports[`escape regexp 1`] = `
+Snapshot: <g>/\\\\\\\\\\("\\)/g</>
+Received: <r>/\\\\\\\\\\("\\)/</>
+`;
+
+exports[`expand false 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<y>@@ -12,7 +12,9 @@</>
+<d>  ? "number"</>
+<d>  : T extends boolean</>
+<d>  ? "boolean"</>
+<d>  : T extends undefined</>
+<d>  ? "undefined"</>
+<g>- : T extends Function<i> </i>? "function"<i> </i>: "object";</>
+<r>+ : T extends Function</>
+<r>+ ? "function"</>
+<r>+ : "object";</>
+<d>  ↵</>
+`;
+
+exports[`expand true 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<d>  type TypeName<T> =</>
+<d>  T extends string ? "string" :</>
+<d>  T extends number ? "number" :</>
+<d>  T extends boolean ? "boolean" :</>
+<d>  T extends undefined ? "undefined" :</>
+<d>  T extends Function ? "function" :</>
+<d>  "object";</>
+<d>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</>
+<d>  type TypeName<T> = T extends string</>
+<d>  ? "string"</>
+<d>  : T extends number</>
+<d>  ? "number"</>
+<d>  : T extends boolean</>
+<d>  ? "boolean"</>
+<d>  : T extends undefined</>
+<d>  ? "undefined"</>
+<g>- : T extends Function<i> </i>? "function"<i> </i>: "object";</>
+<r>+ : T extends Function</>
+<r>+ ? "function"</>
+<r>+ : "object";</>
+<d>  ↵</>
+`;
+
+exports[`fallback to line diff 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<r>+ ====================================options=====================================</>
+<r>+ parsers: ["flow", "typescript"]</>
+<r>+ printWidth: 80</>
+<r>+                                                                                 | printWidth</>
+<r>+ =====================================input======================================</>
+<d>  [...a, ...b,];</>
+<d>  [...a, ...b];</>
+<g>- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</>
+<r>+ </>
+<r>+ =====================================output=====================================</>
+<d>  [...a, ...b];</>
+<d>  [...a, ...b];</>
+<d>  </>
+<r>+ ================================================================================</>
+`;
+
+exports[`isLineDiffable false boolean 1`] = `
+Snapshot: <g>true</>
+Received: <r>false</>
+`;
+
+exports[`isLineDiffable false number 1`] = `
+Snapshot: <g>-0</>
+Received: <r>NaN</>
+`;
+
+exports[`isLineDiffable true array 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<d>  Array [</>
+<d>    Object {</>
+<r>+     "_id": "b14680dec683e744ada1f2fe08614086",</>
+<d>      "code": 4011,</>
+<d>      "weight": 2.13,</>
+<d>    },</>
+<d>    Object {</>
+<r>+     "_id": "7fc63ff01769c4fa7d9279e97e307829",</>
+<d>      "code": 4019,</>
+<d>      "count": 4,</>
+<d>    },</>
+<d>  ]</>
+`;
+
+exports[`isLineDiffable true object 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<d>  Object {</>
+<d>    "props": Object {</>
+<g>-     "className": "logo",</>
+<g>-     "src": "/img/jest.png",</>
+<r>+     "alt": "Jest logo",</>
+<r>+     "class": "logo",</>
+<r>+     "src": "/img/jest.svg",</>
+<d>    },</>
+<d>    "type": "img",</>
+<d>  }</>
+`;
+
+exports[`isLineDiffable true single line expected and received 1`] = `
+Snapshot: <g>Array []</>
+Received: <r>Object {}</>
+`;
+
+exports[`multi line small change in one line and other is unchanged 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<g>- There is no route defined for key <i>'</i>Settings<i>'</i>.</>
+<r>+ There is no route defined for key Settings.</>
+<d>  Must be one of: 'Home'</>
+`;
+
+exports[`multi line small changes 1`] = `
+<g>- Snapshot</>
+<r>+ Received</>
+
+<g>-     6<i>9</i> |·</>
+<r>+     6<i>8</i> |·</>
+<g>-     <i>70</i> | test('assert.doesNotThrow', () => {</>
+<r>+     <i>69</i> | test('assert.doesNotThrow', () => {</>
+<g>-   > 7<i>1</i> |   assert.doesNotThrow(() => {</>
+<r>+   > 7<i>0</i> |   assert.doesNotThrow(() => {</>
+<d>         |          ^</>
+<g>-     7<i>2</i> |     throw Error('err!');</>
+<r>+     7<i>1</i> |     throw Error('err!');</>
+<g>-     7<i>3</i> |   });</>
+<r>+     7<i>2</i> |   });</>
+<g>-     7<i>4</i> | });</>
+<r>+     7<i>3</i> | });</>
+<g>-     at Object.doesNotThrow (__tests__/assertionError.test.js:7<i>1</i>:10)</>
+<r>+     at Object.doesNotThrow (__tests__/assertionError.test.js:7<i>0</i>:10)</>
+`;
+
+exports[`single line large changes 1`] = `
+Snapshot: <g>"<i>A</i>rray length<i> must be a finite positive integer</i>"</>
+Received: <r>"<i>Invalid a</i>rray length"</>
+`;