[jest-each] Add pretty format

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Features
 
+- `[jest-each]` Add pretty-format serialising to each titles ([#6357](https://github.com/facebook/jest/pull/6357))
 - `[jest-cli]` shouldRunTestSuite watch hook now receives an object with `config`, `testPath` and `duration` ([#6350](https://github.com/facebook/jest/pull/6350))
 - `[jest-each]` Support one dimensional array of data ([#6351](https://github.com/facebook/jest/pull/6351))
 - `[jest-watch]` create new package `jest-watch` to ease custom watch plugin development ([#6318](https://github.com/facebook/jest/pull/6318))

docs/GlobalAPI.md

@@ -233,6 +233,7 @@ Use `describe.each` if you keep duplicating the same test suites with different
 - `table`: `Array` of Arrays with the arguments that are passed into the `fn` for each row.
 - `name`: `String` the title of the test suite.
   - Generate unique test titles by positionally injecting parameters with [`printf` formatting](https://nodejs.org/api/util.html#util_util_format_format_args):
+    - `%p` - [pretty-format](https://www.npmjs.com/package/pretty-format).
     - `%s`- String.
     - `%d`- Number.
     - `%i` - Integer.
@@ -477,6 +478,7 @@ Use `test.each` if you keep duplicating the same test with different data. `test
 - `table`: `Array` of Arrays with the arguments that are passed into the test `fn` for each row.
 - `name`: `String` the title of the test block.
   - Generate unique test titles by positionally injecting parameters with [`printf` formatting](https://nodejs.org/api/util.html#util_util_format_format_args):
+    - `%p` - [pretty-format](https://www.npmjs.com/package/pretty-format).
     - `%s`- String.
     - `%d`- Number.
     - `%i` - Integer.

e2e/__tests__/__snapshots__/each.test.js.snap

@@ -1,5 +1,39 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`formats args with pretty format when given %p 1`] = `
+"PASS __tests__/pretty.test.js
+  array
+    ✓ \\"hello\\" == \\"hello\\"
+    ✓ 1 == 1
+    ✓ null == null
+    ✓ undefined == undefined
+    ✓ 1.2 == 1.2
+    ✓ {\\"foo\\": \\"bar\\"} == {\\"foo\\": \\"bar\\"}
+    ✓ {\\"foo\\": [Object]} == {\\"foo\\": [Object]}
+    ✓ [Function noop] == [Function noop]
+    ✓ [] == []
+    ✓ [[Object]] == [[Object]]
+    ✓ Infinity == Infinity
+    ✓ -Infinity == -Infinity
+    ✓ NaN == NaN
+  template
+    ✓ \\"hello\\" == \\"hello\\"
+    ✓ 1 == 1
+    ✓ null == null
+    ✓ undefined == undefined
+    ✓ 1.2 == 1.2
+    ✓ {\\"foo\\": \\"bar\\"} == {\\"foo\\": \\"bar\\"}
+    ✓ {\\"foo\\": [Object]} == {\\"foo\\": [Object]}
+    ✓ [Function noop] == [Function noop]
+    ✓ [] == []
+    ✓ [[Object]] == [[Object]]
+    ✓ Infinity == Infinity
+    ✓ -Infinity == -Infinity
+    ✓ NaN == NaN
+
+"
+`;
+
 exports[`runs only the describe.only.each tests 1`] = `
 "PASS __tests__/describe-only.test.js
   passes all rows expected true == true
@@ -79,9 +113,9 @@ exports[`shows the correct errors in stderr when failing tests 1`] = `
   ✕ The word red contains the letter 'z'
   ✕ The word green contains the letter 'z'
   ✕ The word bean contains the letter 'z'
-  template table describe fails on all rows expected a == b
+  template table describe fails on all rows expected \\"a\\" == \\"b\\"
     ✕ fails
-  template table describe fails on all rows expected c == d
+  template table describe fails on all rows expected \\"c\\" == \\"d\\"
     ✕ fails
   array table describe fails on all rows expected a == b
     ✕ fails
@@ -241,7 +275,7 @@ exports[`shows the correct errors in stderr when failing tests 1`] = `
 
       at __tests__/failure.test.js:47:28
 
-  ● template table describe fails on all rows expected a == b › fails
+  ● template table describe fails on all rows expected \\"a\\" == \\"b\\" › fails
 
     expect(received).toBe(expected) // Object.is equality
 
@@ -258,7 +292,7 @@ exports[`shows the correct errors in stderr when failing tests 1`] = `
 
       at __tests__/failure.test.js:59:20
 
-  ● template table describe fails on all rows expected c == d › fails
+  ● template table describe fails on all rows expected \\"c\\" == \\"d\\" › fails
 
     expect(received).toBe(expected) // Object.is equality
 

e2e/__tests__/each.test.js

@@ -56,3 +56,10 @@ test('runs only the describe.only.each tests', () => {
   expect(rest).toMatchSnapshot();
   expect(result.status).toBe(0);
 });
+
+test('formats args with pretty format when given %p', () => {
+  const result = runJest(dir, ['pretty.test.js']);
+  const {rest} = extractSummary(result.stderr);
+  expect(rest).toMatchSnapshot();
+  expect(result.status).toBe(0);
+});

e2e/each/__tests__/pretty.test.js

@@ -0,0 +1,49 @@
+/**
+ * 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.
+ */
+
+const noop = () => {};
+
+describe('array', () => {
+  it.each([
+    ['hello', 'hello'],
+    [1, 1],
+    [null, null],
+    [undefined, undefined],
+    [1.2, 1.2],
+    [{foo: 'bar'}, {foo: 'bar'}],
+    [{foo: {bar: 'baz'}}, {foo: {bar: 'baz'}}],
+    [noop, noop],
+    [[], []],
+    [[{foo: {bar: 'baz'}}], [{foo: {bar: 'baz'}}]],
+    [Infinity, Infinity],
+    [-Infinity, -Infinity],
+    [NaN, NaN],
+  ])('%p == %p', (left, right) => {
+    expect(left).toEqual(right);
+  });
+});
+
+describe('template', () => {
+  it.each`
+    left                     | right
+    ${'hello'}               | ${'hello'}
+    ${1}                     | ${1}
+    ${null}                  | ${null}
+    ${undefined}             | ${undefined}
+    ${1.2}                   | ${1.2}
+    ${{foo: 'bar'}}          | ${{foo: 'bar'}}
+    ${{foo: {bar: 'baz'}}}   | ${{foo: {bar: 'baz'}}}
+    ${noop}                  | ${noop}
+    ${[]}                    | ${[]}
+    ${[{foo: {bar: 'baz'}}]} | ${[{foo: {bar: 'baz'}}]}
+    ${Infinity}              | ${Infinity}
+    ${-Infinity}             | ${-Infinity}
+    ${NaN}                   | ${NaN}
+  `('$left == $right', ({left, right}) => {
+    expect(left).toEqual(right);
+  });
+});

packages/jest-each/README.md

@@ -26,6 +26,7 @@ jest-each allows you to provide multiple arguments to your `test`/`describe` whi
   - Also under the aliases: `.xdescribe`
 - Asynchronous tests with `done`
 - Unique test titles with [`printf` formatting](https://nodejs.org/api/util.html#util_util_format_format_args):
+  - `%p` - [pretty-format](https://www.npmjs.com/package/pretty-format).
   - `%s`- String.
   - `%d`- Number.
   - `%i` - Integer.
@@ -100,6 +101,7 @@ const each = require('jest-each');
 
 - name: `String` the title of the `test`.
   - Generate unique test titles by positionally injecting parameters with [`printf` formatting](https://nodejs.org/api/util.html#util_util_format_format_args):
+    - `%p` - [pretty-format](https://www.npmjs.com/package/pretty-format).
     - `%s`- String.
     - `%d`- Number.
     - `%i` - Integer.
@@ -119,6 +121,7 @@ const each = require('jest-each');
 
 - name: `String` the title of the `describe`
   - Generate unique test titles by positionally injecting parameters with [`printf` formatting](https://nodejs.org/api/util.html#util_util_format_format_args):
+    - `%p` - [pretty-format](https://www.npmjs.com/package/pretty-format).
     - `%s`- String.
     - `%d`- Number.
     - `%i` - Integer.

packages/jest-each/src/__tests__/array.test.js

@@ -6,6 +6,7 @@
  *
  */
 
+import pretty from 'pretty-format';
 import each from '../';
 
 const noop = () => {};
@@ -140,6 +141,52 @@ describe('jest-each', () => {
         );
       });
 
+      test('calls global test title with %p placeholder injected at the correct positions', () => {
+        const globalTestMocks = getGlobalTestMocks();
+        const eachObject = each.withGlobal(globalTestMocks)([
+          ['string1', 'pretty1', 'string2', 'pretty2'],
+          ['string1', 'pretty1', 'string2', 'pretty2'],
+        ]);
+        const testFunction = get(eachObject, keyPath);
+        testFunction('expected string: %s %p %s %p', noop);
+
+        const globalMock = get(globalTestMocks, keyPath);
+        expect(globalMock).toHaveBeenCalledTimes(2);
+        expect(globalMock).toHaveBeenCalledWith(
+          `expected string: string1 ${pretty('pretty1')} string2 ${pretty(
+            'pretty2',
+          )}`,
+          expectFunction,
+        );
+        expect(globalMock).toHaveBeenCalledWith(
+          `expected string: string1 ${pretty('pretty1')} string2 ${pretty(
+            'pretty2',
+          )}`,
+          expectFunction,
+        );
+      });
+
+      test('does not calls global test title with %p placeholder when no data is supplied at given position', () => {
+        const globalTestMocks = getGlobalTestMocks();
+        const eachObject = each.withGlobal(globalTestMocks)([
+          ['string1', 'pretty1', 'string2'],
+          ['string1', 'pretty1', 'string2'],
+        ]);
+        const testFunction = get(eachObject, keyPath);
+        testFunction('expected string: %s %p %s %p', noop);
+
+        const globalMock = get(globalTestMocks, keyPath);
+        expect(globalMock).toHaveBeenCalledTimes(2);
+        expect(globalMock).toHaveBeenCalledWith(
+          `expected string: string1 ${pretty('pretty1')} string2 %p`,
+          expectFunction,
+        );
+        expect(globalMock).toHaveBeenCalledWith(
+          `expected string: string1 ${pretty('pretty1')} string2 %p`,
+          expectFunction,
+        );
+      });
+
       test('calls global with cb function containing all parameters of each test case when given 1d array', () => {
         const globalTestMocks = getGlobalTestMocks();
         const testCallBack = jest.fn();

packages/jest-each/src/bind.js

@@ -12,10 +12,15 @@ import chalk from 'chalk';
 import pretty from 'pretty-format';
 
 type Table = Array<Array<any>>;
+type PrettyArgs = {
+  args: Array<mixed>,
+  title: string,
+};
 
 const EXPECTED_COLOR = chalk.green;
 const RECEIVED_COLOR = chalk.red;
-const SUPPORTED_PLACEHOLDERS = /%[sdifjoO%]/g;
+const SUPPORTED_PLACEHOLDERS = /%[sdifjoOp%]/g;
+const PRETTY_PLACEHOLDER = '%p';
 
 export default (cb: Function) => (...args: any) =>
   function eachBind(title: string, test: Function): void {
@@ -59,9 +64,41 @@ export default (cb: Function) => (...args: any) =>
     );
   };
 
-const arrayFormat = (str, ...args) => {
-  const matches = (str.match(SUPPORTED_PLACEHOLDERS) || []).length;
-  return util.format(str, ...args.slice(0, matches));
+const getPrettyIndexes = placeholders =>
+  placeholders.reduce(
+    (indexes, placeholder, index) =>
+      placeholder === PRETTY_PLACEHOLDER ? indexes.concat(index) : indexes,
+    [],
+  );
+
+const arrayFormat = (title, ...args) => {
+  const placeholders = title.match(SUPPORTED_PLACEHOLDERS) || [];
+  const prettyIndexes = getPrettyIndexes(placeholders);
+
+  const {title: prettyTitle, args: remainingArgs} = args.reduce(
+    (acc: PrettyArgs, arg, index) => {
+      if (prettyIndexes.indexOf(index) !== -1) {
+        return {
+          args: acc.args,
+          title: acc.title.replace(
+            PRETTY_PLACEHOLDER,
+            pretty(arg, {maxDepth: 1, min: true}),
+          ),
+        };
+      }
+
+      return {
+        args: acc.args.concat([arg]),
+        title: acc.title,
+      };
+    },
+    {args: [], title},
+  );
+
+  return util.format(
+    prettyTitle,
+    ...remainingArgs.slice(0, placeholders.length - prettyIndexes.length),
+  );
 };
 
 const applyRestParams = (params: Array<any>, test: Function) => {
@@ -89,7 +126,8 @@ const buildTable = (
 
 const interpolate = (title: string, data: any) =>
   Object.keys(data).reduce(
-    (acc, key) => acc.replace('$' + key, data[key]),
+    (acc, key) =>
+      acc.replace('$' + key, pretty(data[key], {maxDepth: 1, min: true})),
     title,
   );