Jest-preset-angular: TypeError: test.each is not a function

[marcojahn]

Trying to use Jest 23 "test.each" error results in a TypeError.

Test

  test.each([[1, 1, 2], [1, 2, 3], [2, 1, 3]])(
    '.add(%i, %i)',
    (a, b, expected) => {
      expect(a + b).toBe(expected);
    },
  );

Error Message

 FAIL  src/app/wte/components/my-component.component.spec.ts (204 MB heap size)
  MyComponent
    ✓ should create (743ms)
    ✕ encountered a declaration exception (625ms)

  ● MyComponent › encountered a declaration exception

    TypeError: test.each is not a function

      27 |   });
      28 |
    > 29 |   test.each([[1, 1, 2], [1, 2, 3], [2, 1, 3]])(
         |        ^
      30 |     '.add(%i, %i)',
      31 |     (a, b, expected) => {
      32 |       expect(a + b).toBe(expected);

      at src/app/wte/components/my-component.component.spec.ts:29:8
      at ZoneDelegate.Object.<anonymous>.ZoneDelegate.invoke (node_modules/zone.js/dist/zone.js:388:26)
      at Zone.Object.<anonymous>.Zone.run (node_modules/zone.js/dist/zone.js:138:43)
      at Suite.<anonymous> (node_modules/jest-zone-patch/index.js:39:25)
      at env.(anonymous function) (node_modules/jest-zone-patch/index.js:57:27)
      at Object.<anonymous> (src/app/wte/components/my-component.component.spec.ts:8:1)

Any suggestions what am I missing ?

regards

[thymikee]

Looks like you're not the only one :D https://github.com/facebook/jest/issues/6612
We're not yet officially compatible with Jest 23, because we're waiting for ts-jest to update.
I see however that more folks try to use it and it mostly works. What needs to be updated on our side is jest-zone-patch, as it doesn't account for new additions to test() fn. Happy to accept PR with a fix :)

[marcojahn]

ok, seems to belong to https://github.com/facebook/jest/issues/6612

Installing jest-each does not resolve the problem either

[marcojahn]

@thymikee

could it be so simple ? Or is there something I do not think about ?

Will write some tests for my code and will create a PR this evening or tomorrow

['xit', 'fit', 'test', 'it'].forEach(methodName => {
  const originaljestFn = env[methodName];
  env[methodName] = function(description, specDefinitions, timeout) {
    arguments[1] = wrapTestInZone(specDefinitions);
    return originaljestFn.apply(this, arguments);
  };
  if (methodName === 'test' || methodName === 'it') {
    env[methodName].only = env['fit'];
    env[methodName].skip = env['xit'];

    // modification is below this point
    // test.each(table)(name, fn)
    env[methodName].each = function (description, specDefinitions) {
      arguments[1] = wrapTestInZone(specDefinitions);
      return originaljestFn.each.apply(this, arguments);
    };
    // end of modification
  }
});

Does successfully handle both testcases (ok and failure)

  it.each([[1, 1, 2], [1, 2, 3], [2, 1, 3]])('.add(%i, %i)', (a, b, expected) => {
    expect(a + b).toBe(expected);
  });

  it.each`
    init | incr | expected
    ${11} | ${1} | ${12}
    `('can handle +1 steps', ({init, incr, expected}) => {
      component.initialSeatNumber = init;
      component.onPlatznummerChangeBy(incr);
      expect(MatrixManagerService.NEXT_SEAT_NUMBER).toEqual(expected);
    });

[thymikee]

test.each has different function signature: https://github.com/facebook/jest/blob/master/packages/jest-each/src/bind.js
Not sure if it matters for zone to work though.

[marcojahn]

@thymikee there is a PR
https://github.com/thymikee/jest-zone-patch/pull/7

But there seems to be a bug when having multiple entries in the table (using just the "array" methodology the test is working), maybe you can help

test.each`
  a    | b    | expected
  ${1} | ${1} | ${2}
  ${1} | ${2} | ${3}
  ${2} | ${1} | ${3}
`('returns $expected when $a is added $b', ({a, b, expected}) => {
      expect(a + b).toBe(expected);
    });

results in the following

 FAIL  src/app/wte/components/MyComponent.component.spec.ts (389 MB heap size)
  MyComponent
    ✓ should create (1228ms)
      ✕ returns 2 when [Function anonymous] is added 1 (732ms)
      ✓ returns 3 when 1 is added 2 (655ms)
      ✓ returns 3 when 2 is added 1 (637ms)

  ● MyComponent › returns 2 when [Function anonymous] is added 1

    expect(received).toBe(expected) // Object.is equality

    Expected: 2
    Received: "done => testProxyZone.run(testBody, null, [done])1"

    Difference:

      Comparing two different types of values. Expected number but received string.

      38 |   ${2} | ${1} | ${3}
      39 | `('returns $expected when $a is added $b', ({a, b, expected}) => {
    > 40 |       expect(a + b).toBe(expected);
         |                     ^
      41 |     });
      42 |
      43 |     /*it.only.each`

      at src/app/wte/components/MyComponent.component.spec.ts:40:21

Test Suites: 1 failed, 1 total
Tests:       1 failed, 3 passed, 4 total
Snapshots:   0 total
Time:        4.168s
Ran all test suites matching /wte-naechs/i.

Watch Usage: Press w to show more.

This one works

test.each([[1, 1, 2], [1, 2, 3], [2, 1, 3]])(
      '.add(%i, %i)',
      (a, b, expected) => {
        expect(a + b).toBe(expected);
      },
    );

[kirillgroshkov]

Waiting for a fix too...

[thymikee]

Just merged and released https://github.com/thymikee/jest-zone-patch/pull/8 so re-installing the preset should bump the jest-zone-patch and test.each should work now. Lemme know if you have any issues.

[thymikee]

Turned out I need to publish another release. Fixed in v6.0.2

[NagRock]

Will describe.each also be supported?

[thymikee]

Should be supported, doesn't it work?

[ahnpnl]

it is supported by this line https://github.com/thymikee/jest-zone-patch/blob/3c8aa04279c9c9de1edc75b4e0665c7a282ce3ba/index.js#L78 I guess ?

[NagRock]

it.each works but example of describe.each from jest documentation:

describe.each([[1, 1, 2], [1, 2, 3], [2, 1, 3]])(
  '.add(%i, %i)',
  (a, b, expected) => {
    test(`returns ${expected}`, () => {
      expect(a + b).toBe(expected);
    });

    test(`returned value not be greater than ${expected}`, () => {
      expect(a + b).not.toBeGreaterThan(expected);
    });

    test(`returned value not be less than ${expected}`, () => {
      expect(a + b).not.toBeLessThan(expected);
    });
  },
);

Fails:

```.add(2, 1) › returned value not be less than undefined

expect(received)[.not].toBeLessThan(expected)

Received value must be a number.
Received:
  string: "function (a, b, expected) {
        test(\"returns \" + expected, function () {
            expect(a + b).toBe(expected);
        });
        test(\"returned value not be greater than \" + expected, function () {
            expect(a + b).not.toBeGreaterThan(expected);
        });
        test(\"returned value not be less than \" + expected, function () {
            expect(a + b).not.toBeLessThan(expected);
        });
    }undefined"

  45 |
  46 |       test(`returned value not be less than ${expected}`, () => {
> 47 |         expect(a + b).not.toBeLessThan(expected);
     |                           ^
  48 |       });
  49 |     },
  50 |   );

```

Looks like function is passed to expected argument instead of test data.

[thymikee]

cc @JLHwung

[thymikee]

@NagRock Should be good now, you'll need to re-install to update the transitive dependency of jest-zone-patch

[NagRock]

Thanks. I will check it and get back with feedback.

[NagRock]

@thymikee Works like a charm 🎉 Thanks!