Jest: Inline snapshots drift to the right

Created on 6 May 2019 · 15Comments · Source: facebook/jest

💥 Regression Report

Inline snapshots are re-indented whenever another inline snapshot in the same file is saved/updated.

Last working version

Worked up to version: 24.5

Stopped working in version: 24.6

To Reproduce

Steps to reproduce the behavior:

Given this test file and we're running in watch mode:

describe('broken', () => {
  test('1', () => {
    expect(11111).toMatchInlineSnapshot();
  });

  test('2', () => {
    expect([[1]]).toMatchInlineSnapshot();
  });
});

Upon save, both snapshots are written:

describe('broken', () => {
  test('1', () => {
    expect(11111).toMatchInlineSnapshot(`11111`);
  });

  test('2', () => {
    expect([[1]]).toMatchInlineSnapshot(`
      Array [
        Array [
          1,
        ],
      ]
    `);
  });
});

Now I update the first test (expect(10000).toMatchInlineSnapshot()) and save. The snapshots get rewritten:

describe('broken', () => {
  test('1', () => {
    expect(10000).toMatchInlineSnapshot(`10000`);
  });

  test('2', () => {
    expect([[1]]).toMatchInlineSnapshot(`
            Array [
              Array [
                1,
              ],
            ]
        `);
  });
});

Now I add another test (expect(3).toMatchInlineSnapshot()) and save:

describe('broken', () => {
  test('1', () => {
    expect(10000).toMatchInlineSnapshot(`10000`);
  });

  test('2', () => {
    expect([[1]]).toMatchInlineSnapshot(`
                  Array [
                    Array [
                      1,
                    ],
                  ]
            `);
  });

  test('3', () => {
    expect(3).toMatchInlineSnapshot(`3`);
  });
});

Notice how the snapshot for test 2 slowly drifts to the right. This can get super annoying after many test-update-save cycles.

Expected behavior

Inline snapshots should stay put.

Link to repl or repo (highly encouraged)

Repl.it only has Jest 22.1.2. I didn't find a way to upgrade it.

Run `npx envinfo --preset jest`

Paste the results here:

  System:
    OS: macOS Mojave 10.14.4
    CPU: (4) x64 Intel(R) Core(TM) i7-7567U CPU @ 3.50GHz
  Binaries:
    Node: 10.15.0 - ~/.nvm/versions/node/v10.15.0/bin/node
    Yarn: 1.15.2 - /usr/local/bin/yarn
    npm: 6.4.1 - ~/.nvm/versions/node/v10.15.0/bin/npm
  npmPackages:
    jest: ^24.6.0 => 24.7.1

Regression

Source