mirror of
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b80cb629c6
## Summary - Fix `mock.mock.args` to `mock.mock.calls` in mock-functions.mdx (the `.args` property doesn't exist) - Fix mock.restore example to use module methods instead of spy functions (calling spy functions after restore returns `undefined`) - Add missing `vi` import in Vitest compatibility example ## Test plan - [x] Verified each code block works by running tests against the debug build 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude Bot <claude-bot@bun.sh> Co-authored-by: Claude <noreply@anthropic.com>
71 lines
1.7 KiB
Plaintext
71 lines
1.7 KiB
Plaintext
---
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title: Mock functions in `bun test`
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sidebarTitle: Mock functions
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mode: center
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---
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Create mocks with the `mock` function from `bun:test`.
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```ts test.ts icon="/icons/typescript.svg"
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import { test, expect, mock } from "bun:test";
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const random = mock(() => Math.random());
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```
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---
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The mock function can accept arguments.
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```ts test.ts icon="/icons/typescript.svg"
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import { test, expect, mock } from "bun:test";
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const random = mock((multiplier: number) => multiplier * Math.random());
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```
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---
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The result of `mock()` is a new function that's been decorated with some additional properties.
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```ts test.ts icon="/icons/typescript.svg"
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import { mock } from "bun:test";
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const random = mock((multiplier: number) => multiplier * Math.random());
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random(2);
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random(10);
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random.mock.calls;
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// [[ 2 ], [ 10 ]]
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random.mock.results;
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// [
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// { type: "return", value: 0.6533907460954099 },
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// { type: "return", value: 0.6452713933037312 }
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// ]
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```
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---
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These extra properties make it possible to write `expect` assertions about usage of the mock function, including how many times it was called, the arguments, and the return values.
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```ts test.ts icon="/icons/typescript.svg"
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import { test, expect, mock } from "bun:test";
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const random = mock((multiplier: number) => multiplier * Math.random());
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test("random", async () => {
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const a = random(1);
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const b = random(2);
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const c = random(3);
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expect(random).toHaveBeenCalled();
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expect(random).toHaveBeenCalledTimes(3);
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expect(random.mock.calls).toEqual([[1], [2], [3]]);
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expect(random.mock.results[0]).toEqual({ type: "return", value: a });
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});
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```
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---
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See [Docs > Test Runner > Mocks](/test/mocks) for complete documentation on mocking with the Bun test runner.
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