Vitest Snippets

Vitest Snippets for Zed Editor

A comprehensive collection of Vitest snippets designed to speed up test development in the Zed editor.

Installation

To use these snippets in Zed:

1. Open Zed
2. Go to Settings → Snippets
3. Click Configure Snippets
4. Select the appropriate language (JavaScript or TypeScript)
5. Paste the content from the relevant snippet file

Available Snippets

Basic Test Structure

• bench(name, fn, options?) - Creates an individual benchmark case.
• describe(name, fn) - Creates a test suite to group related tests.
• it(name, fn, options?) - An alias for test.
• test(name, fn, options?) - Creates an individual test case.

Describe

• describe.concurrent(name, fn) - Runs all tests in this suite concurrently.
• describe.each(cases)(name, fn) - Runs a suite multiple times with different data.
• describe.for(cases)(name, fn) - Runs a suite multiple times with different data.
• describe.only(name, fn) - Runs only this test suite.
• describe.runIf(condition)(name, fn?) - Runs this test suite only if the condition is true.
• describe.sequential(name, fn) - Runs all tests in this suite sequentially.
• describe.shuffle(name, fn) - Runs all tests in this suite in a random order.
• describe.skip(name, fn?) - Skips this test suite.
• describe.skipIf(condition)(name, fn?) - Skips this test suite if the condition is true.
• describe.todo(name) - Marks a test suite as not yet implemented.

Test

• test.concurrent(name, fn) - Runs this test concurrently with others.
• test.each(cases)(name, fn) - Runs a test multiple times with different data.
• test.extends - extend the test context with custom fixtures
• test.only(name, fn) - Runs only this test (and other .only tests).
• test.runIf(condition)(name, fn) - Runs the test only if the condition is true.
• test.skip(name, fn?) - Skips this test.
• test.skipIf(condition)(name, fn?) - Skips this test if the condition is true.
• test.todo(name) - Marks a test as not yet implemented.

Bench

• bench.skip(name, fn?) - Skips this benchmark.
• bench.only(name, fn) - Runs only this benchmark.
• bench.todo(name) - Marks a benchmark as not yet implemented.

Setup and Teardown

• afterAll(fn) - Runs a function once after all tests in the suite.
• afterEach(fn) - Runs a function after each test in the suite.
• beforeAll(fn) - Runs a function once before all tests in the suite.
• beforeEach(fn) - Runs a function before each test in the suite.

Test Hooks

• onTestFailed(fn) - Registers a function to run when the test fails.
• onTestFinished(fn) - Registers a cleanup function to run when the test finishes.

Mocks

• .getMockImplementation() - Returns the current mock implementation.
• .getMockName() - Returns the custom name for the mock.
• .mockClear() - Clears call and instance history.
• .mockName(name) - Sets a custom name for the mock.
• .mockImplementation(fn) - Sets the default implementation of a mock.
• .mockImplementationOnce(fn) - Sets a one-time implementation.
• .withImplementation(fn, cb) - Runs a callback with a temporary implementation.
• .mockRejectedValue(error) - Sets an error to be returned as a rejected promise.
• .mockRejectedValueOnce(error) - Sets a one-time error to be returned as a rejected promise.
• .mockReset() - Clears history and resets implementation to vi.fn().
• .mockRestore() - Clears history and restores the original implementation (for spies).
• .mockResolvedValue(value) - Sets a value to be returned as a resolved promise.
• .mockResolvedValueOnce(value) - Sets a one-time value to be returned as a resolved promise.
• .mockReturnThis() - Sets the mock to return this context.
• .mockReturnValue(value) - Sets a value to be returned.
• .mockReturnValueOnce(value) - Sets a one-time value to be returned.
• .mock.calls - An array containing all call arguments.
• .mock.lastCall - The arguments of the last call.
• .mock.results - An array containing all call results (return/throw).
• .mock.settledResults - An array of settled promise results.
• .mock.invocationCallOrder - An array of invocation call orders.
• .mock.contexts - An array of this contexts for all calls.
• .mock.instances - An array of instances created by the mock.

Vi Utility

Mock Modules

• vi.doMock(path, factory?) - Mocks a module without hoisting (for circular dependencies).
• vi.doUnmock(path) - Unmocks a module (non-hoisted version of vi.unmock).
• vi.dynamicImportSettled() - Waits for all dynamic imports to resolve or reject.
• vi.importActual(path) - Imports a module, bypassing any mocks.
• vi.importMock(path) - Imports a module with all its exports mocked.
• vi.mock(path, factory?) - Mocks an entire module (must be hoisted).
• vi.mocked(value, deep?) - Type-casts a value as a mock, asserting its mock type.
• vi.resetModules() - Clears the module import cache.
• vi.unmock(path) - Specifies that a module should not be mocked (hoisted).

Mocking Functions and Objects

• vi.clearAllMocks() - Clears mock.calls and mock.instances for all mocks.
• vi.fn(implementation?) - Creates a new, empty mock function.
• vi.isMockFunction(fn) - Checks if a value is a mock function or spy.
• vi.mockObject(object, overrides?) - Creates a deep mock of an object.
• vi.resetAllMocks() - Resets all mocks (clears history, instances, and resets implementations).
• vi.restoreAllMocks() - Restores all spies and mocks to their original implementations.
• vi.spyOn(object, 'methodName') - Creates a spy on an existing object method.
• vi.stubEnv(name, value) - Stubs an environment variable (process.env).
• vi.stubGlobal(name, value) - Stubs a global variable.
• vi.unstubAllEnvs() - Restores all stubbed environment variables.
• vi.unstubAllGlobals() - Restores all stubbed global variables.

Fake Timers

• vi.advanceTimersByTime(ms) - Advances fake timers by a specified time (in ms).
• vi.advanceTimersByTimeAsync(ms) - Advances fake timers by time (async version).
• vi.advanceTimersToNextFrame() - Advances timers to the next requestAnimationFrame.
• vi.advanceTimersToNextTimer() - Advances timers to the next scheduled timer.
• vi.advanceTimersToNextTimerAsync() - Advances to the next timer (async version).
• vi.clearAllTimers() - Clears all pending timers.
• vi.getMockedSystemTime() - Gets the current mocked system time.
• vi.getRealSystemTime() - Gets the current real system time.
• vi.getTimerCount() - Returns the number of pending timers.
• vi.isFakeTimers() - Checks if timers are currently mocked.
• vi.runAllTicks() - Runs all pending microtasks (e.g., process.nextTick).
• vi.runAllTimers() - Runs all pending macrotasks (timers).
• vi.runAllTimersAsync() - Runs all pending macrotasks (async version).
• vi.runOnlyPendingTimers() - Runs only currently pending timers.
• vi.runOnlyPendingTimersAsync() - Runs only pending timers (async version).
• vi.setSystemTime(date) - Sets the system time when fake timers are in use.
• vi.useFakeTimers() - Mocks timer functions (setTimeout, setInterval).
• vi.useRealTimers() - Restores real timer functions.

Miscellaneous

• vi.hoisted(fn) - Hoists a function to the top (used inside vi.mock).
• vi.resetConfig() - Resets Vitest configuration to its default.
• vi.setConfig(config) - Sets Vitest configuration for the current test file.
• vi.waitFor(fn, options?) - Waits for an assertion function to pass.
• vi.waitUntil(fn, options?) - Waits for a condition function to return true.

Assertions (expect)

• expect(value) - The function used to create an assertion.
• expect.assert(value) - Chai's assert API as expect.assert for convenience
• expect.poll(fn, options?) - Polls a function until the assertion passes.
• expect.soft(value) - Creates a soft assertion that doesn't stop the test on failure.
• .not - Inverts the meaning of the next matcher.
• .rejects - Unwraps a promise's rejected reason.
• .resolves - Unwraps a promise's resolved value.
• .toBe(value) - Checks for strict equality (Object.is).
• .toBeCloseTo(number, precision?) - Checks if a number is close to another.
• .toBeDefined() - Checks that a value is not undefined.
• .toBeFalsy() - Checks that a value is falsy.
• .toBeGreaterThan(number) - Checks if a number is greater than another.
• .toBeGreaterThanOrEqual(number) - Checks if a number is greater than or equal.
• .toBeInstanceOf(class) - Checks if a value is an instance of a class.
• .toBeLessThan(number) - Checks if a number is less than another.
• .toBeLessThanOrEqual(number) - Checks if a number is less than or equal.
• .toBeNaN() - Checks that a value is NaN.
• .toBeNull() - Checks that a value is null.
• .toBeNullable() - Checks that a value is null or undefined.
• .toBeOneOf(array) - Checks if a value is one of the members of an array.
• .toBeTruthy() - Checks that a value is truthy.
• .toBeTypeOf(type) - Checks the type of a value (e.g., 'string').
• .toBeUndefined() - Checks that a value is undefined.
• .toContain(value) - Checks if an array or string contains a value.
• .toContainEqual(value) - Checks if an array contains an element with deep equality.
• .toEqual(value) - Deeply checks for equality of properties.
• .toHaveLength(number) - Checks the length of an array or string.
• .toHaveProperty(path, value?) - Checks if an object has a property.
• .toMatch(regexp | string) - Checks if a string matches a regex or substring.
• .toMatchFileSnapshot(filepath) - Compares a value to a snapshot in a separate file.
• .toMatchInlineSnapshot() - Compares a value to an inline snapshot.
• .toMatchObject(object) - Checks if an object contains the specified properties.
• .toMatchSnapshot() - Compares a value to a stored snapshot.
• .toSatisfy(predicate) - Checks if a value satisfies a predicate function.
• .toStrictEqual(value) - Deeply checks for equality, including object types.
• .toThrowError(error?) - Checks that a function throws an error.
• .toThrowErrorMatchingInlineSnapshot() - Checks if an error message matches an inline snapshot.
• .toThrowErrorMatchingSnapshot() - Checks if an error message matches a snapshot.
• expect.assertions(count) - Verifies that a specific number of assertions are called.
• expect.hasAssertions() - Verifies that at least one assertion is called.
• expect.unreachable() - Marks a line as unreachable.
• expect.anything() - Matches any value except null or undefined.
• expect.any(constructor) - Matches any value created with the given constructor.
• expect.closeTo(number, precision?) - Matches a number close to the expected value.
• expect.arrayContaining(array) - Matches an array containing the specified elements.
• expect.objectContaining(object) - Matches an object containing the specified properties.
• expect.stringContaining(string) - Matches a string containing the specified substring.
• expect.stringMatching(regexp) - Matches a string against a regex.
• expect.schemaMatching(schema) - Matches a value against a Zod schema.
• expect.addSnapshotSerializer(serializer) - Adds a custom snapshot serializer.
• expect.extend(matchers) - Adds custom matchers to expect.
• expect.addEqualityTesters(testers) - Adds custom equality testers.

Mock Function Matchers

• .toHaveBeenCalled() - Checks if a mock function was called.
• .toHaveBeenCalledAfter(mock) - Checks if a mock was called after another mock.
• .toHaveBeenCalledBefore(mock) - Checks if a mock was called before another mock.
• .toHaveBeenCalledExactlyOnceWith(...args) - Checks if a mock was called exactly once with specific args.
• .toHaveBeenCalledTimes(number) - Checks how many times a mock was called.
• .toHaveBeenCalledWith(...args) - Checks if a mock was called with specific arguments.
• .toHaveBeenLastCalledWith(...args) - Checks the arguments of the last call.
• .toHaveBeenNthCalledWith(n, ...args) - Checks the arguments of the nth call.
• .toHaveLastReturnedWith(value) - Checks the return value of the last call.
• .toHaveNthReturnedWith(n, value) - Checks the return value of the nth call.
• .toHaveReturned() - Checks if a mock function returned successfully.
• .toHaveReturnedTimes(number) - Checks how many times a mock returned.
• .toHaveReturnedWith(value) - Checks if a mock returned a specific value.

Promise Matchers (.resolves / .rejects)

• .toHaveLastResolvedWith(value) - Checks the last resolved value.
• .toHaveNthResolvedWith(n, value) - Checks the nth resolved value.
• .toHaveResolved() - Checks if a promise resolved.
• .toHaveResolvedTimes(number) - Checks how many times a promise resolved.
• .toHaveResolvedWith(value) - Checks if a promise resolved with a specific value.

Assertions (assert)

• assert(value, message?) - Asserts that a value is truthy.
• assert.changes(fn, object, prop, message?) - Asserts fn changes object[prop].
• assert.changesButNotBy(fn, object, prop, delta, message?) - Asserts fn changes object[prop] but not by delta.
• assert.changesBy(fn, object, prop, delta, message?) - Asserts fn changes object[prop] by delta.
• assert.closeTo(actual, expected, delta, message?) - Asserts |actual - expected| <= delta.
• assert.containsAllDeepKeys(object, keys, message?) - (Alias for hasAllDeepKeys).
• assert.containsAllKeys(object, keys, message?) - (Alias for hasAllKeys).
• assert.decreases(fn, object, prop, message?) - Asserts fn decreases object[prop].
• assert.decreasesButNotBy(fn, object, prop, delta, message?) - Asserts fn decreases object[prop] but not by delta.
• assert.decreasesBy(fn, object, prop, delta, message?) - Asserts fn decreases object[prop] by delta.
• assert.deepEqual(actual, expected, message?) - Asserts deep equality.
• assert.deepInclude(haystack, needle, message?) - Asserts haystack deep-includes needle.
• assert.deepNestedInclude(value, path, needle, message?) - Asserts value has deep-equal needle at path.
• assert.deepNestedPropertyVal(object, path, value, message?) - Asserts nested property path deep equals value.
• assert.deepOwnInclude(value, needle, message?) - Asserts value has deep-equal own property needle.
• assert.deepPropertyVal(object, prop, value, message?) - Asserts object[prop] deep equals value.
• assert.doesNotChange(fn, object, prop, message?) - Asserts fn does not change object[prop].
• assert.doesNotDecrease(fn, object, prop, message?) - Asserts fn does not decrease object[prop].
• assert.doesNotHaveAllDeepKeys(object, keys, message?) - Asserts object does not have all deep keys.
• assert.doesNotHaveAllKeys(object, keys, message?) - Asserts object does not have all keys.
• assert.doesNotHaveAnyDeepKeys(object, keys, message?) - Asserts object has no deep keys.
• assert.doesNotHaveAnyKeys(object, keys, message?) - Asserts object has none of keys.
• assert.doesNotIncrease(fn, object, prop, message?) - Asserts fn does not increase object[prop].
• assert.doesNotThrow(fn, error?, message?) - Asserts fn does not throw error.
• assert.equal(actual, expected, message?) - Asserts non-strict equality (==).
• assert.exists(value, message?) - Asserts value is not null or undefined.
• assert.fail(message?) - Throws an assertion error.
• assert.hasAllDeepKeys(object, keys, message?) - Asserts object has all deep keys.
• assert.hasAllKeys(object, keys, message?) - Asserts object has all keys.
• assert.hasAnyDeepKeys(object, keys, message?) - Asserts object has at least one deep keys.
• assert.hasAnyKeys(object, keys, message?) - Asserts object has at least one of keys.
• assert.ifError(value, message?) - Asserts value is falsy.
• assert.include(haystack, needle, message?) - Asserts haystack.includes(needle).
• assert.includeDeepMembers(superset, subset, message?) - Asserts superset deep-includes all members of subset.
• assert.includeDeepOrderedMembers(superset, subset, message?) - Asserts superset deep-includes all members of subset in order.
• assert.includeMembers(superset, subset, message?) - Asserts superset includes all members of subset.
• assert.includeOrderedMembers(superset, subset, message?) - Asserts superset includes all members of subset in order.
• assert.increases(fn, object, prop, message?) - Asserts fn increases object[prop].
• assert.increasesButNotBy(fn, object, prop, delta, message?) - Asserts fn increases object[prop] but not by delta.
• assert.increasesBy(fn, object, prop, delta, message?) - Asserts fn increases object[prop] by delta.
• assert.instanceOf(value, constructor, message?) - Asserts value instanceof constructor.
• assert.isAbove(value, above, message?) - Asserts value > above.
• assert.isArray(value, message?) - Asserts value is an array.
• assert.isAtLeast(value, atLeast, message?) - Asserts value >= atLeast.
• assert.isAtMost(value, atMost, message?) - Asserts value <= atMost.
• assert.isBelow(value, below, message?) - Asserts value < below.
• assert.isBoolean(value, message?) - Asserts value is a boolean.
• assert.isDefined(value, message?) - Asserts value !== undefined.
• assert.isEmpty(value, message?) - Asserts value is empty.
• assert.isExtensible(object, message?) - Asserts object is extensible.
• assert.isFalse(value, message?) - Asserts value === false.
• assert.isFinite(value, message?) - Asserts value is a finite number.
• assert.isFrozen(object, message?) - Asserts object is frozen.
• assert.isFunction(value, message?) - Asserts value is a function.
• assert.isNaN(value, message?) - Asserts value is NaN.
• assert.isNotArray(value, message?) - Asserts value is not an array.
• assert.isNotBoolean(value, message?) - Asserts value is not a boolean.
• assert.isNotEmpty(value, message?) - Asserts value is not empty.
• assert.isNotExtensible(object, message?) - Asserts object is not extensible.
• assert.isNotFalse(value, message?) - Asserts value !== false.
• assert.isNotFrozen(object, message?) - Asserts object is not frozen.
• assert.isNotFunction(value, message?) - Asserts value is not a function.
• assert.isNotNaN(value, message?) - Asserts value is not NaN.
• assert.isNotNull(value, message?) - Asserts value !== null.
• assert.isNotNumber(value, message?) - Asserts value is not a number.
• assert.isNotObject(value, message?) - Asserts value is not an object.
• assert.isNotOk(value, message?) - Asserts that a value is falsy.
• assert.isNotSealed(object, message?) - Asserts object is not sealed.
• assert.isNotString(value, message?) - Asserts value is not a string.
• assert.isNotTrue(value, message?) - Asserts value !== true.
• assert.isNull(value, message?) - Asserts value === null.
• assert.isNumber(value, message?) - Asserts value is a number.
• assert.isObject(value, message?) - Asserts value is an object.
• assert.isOk(value, message?) - Asserts that a value is truthy.
• assert.isSealed(object, message?) - Asserts object is sealed.
• assert.isString(value, message?) - Asserts value is a string.
• assert.isTrue(value, message?) - Asserts value === true.
• assert.isUndefined(value, message?) - Asserts value === undefined.
• assert.lengthOf(value, length, message?) - Asserts value.length === length.
• assert.match(value, regex, message?) - Asserts regex.test(value).
• assert.nestedInclude(value, path, needle, message?) - Asserts value has needle at path.
• assert.nestedProperty(object, path, message?) - Asserts object has nested property path.
• assert.nestedPropertyVal(object, path, value, message?) - Asserts nested property path equals value.
• assert.notDeepEqual(actual, expected, message?) - Asserts deep inequality.
• assert.notDeepInclude(haystack, needle, message?) - Asserts haystack does not deep-include needle.
• assert.notDeepNestedInclude(value, path, needle, message?) - Asserts value does not have deep-equal needle at path.
• assert.notDeepNestedPropertyVal(object, path, value, message?) - Asserts nested property path does not deep equal value.
• assert.notDeepOwnInclude(value, needle, message?) - Asserts value does not have deep-equal own property needle.
• assert.notDeepPropertyVal(object, prop, value, message?) - Asserts object[prop] does not deep equal value.
• assert.notEqual(actual, expected, message?) - Asserts non-strict inequality (!=).
• assert.notExists(value, message?) - Asserts value is null or undefined.
• assert.notInclude(haystack, needle, message?) - Asserts !haystack.includes(needle).
• assert.notIncludeDeepMembers(superset, subset, message?) - Asserts superset does not deep-include all members of subset.
• assert.notIncludeDeepOrderedMembers(superset, subset, message?) - Asserts superset does not deep-include all members of subset in order.
• assert.notIncludeMembers(superset, subset, message?) - Asserts superset does not include all members of subset.
• assert.notIncludeOrderedMembers(superset, subset, message?) - Asserts superset does not include all members of subset in order.
• assert.notInstanceOf(value, constructor, message?) - Asserts !(value instanceof constructor).
• assert.notMatch(value, regex, message?) - Asserts !regex.test(value).
• assert.notNestedInclude(value, path, needle, message?) - Asserts value does not have needle at path.
• assert.notNestedProperty(object, path, message?) - Asserts object does not have nested property path.
• assert.notNestedPropertyVal(object, path, value, message?) - Asserts nested property path does not equal value.
• assert.notOwnInclude(value, needle, message?) - Asserts value does not have own property needle.
• assert.notProperty(object, prop, message?) - Asserts object does not have property prop.
• assert.notPropertyVal(object, prop, value, message?) - Asserts object[prop] != value.
• assert.notSameDeepMembers(set1, set2, message?) - Asserts set1 and set2 do not have the same deep members.
• assert.notSameDeepOrderedMembers(set1, set2, message?) - Asserts set1 and set2 do not have same deep members in same order.
• assert.notSameMembers(set1, set2, message?) - Asserts set1 and set2 do not have the same members.
• assert.notSameOrderedMembers(set1, set2, message?) - Asserts set1 and set2 do not have same members in same order.
• assert.notTypeOf(value, type, message?) - Asserts typeof value !== type.
• assert.oneOf(value, list, message?) - Asserts value is one of list.
• assert.operator(val1, op, val2, message?) - Asserts val1 op val2 is truthy.
• assert.ownInclude(value, needle, message?) - Asserts value has own property needle.
• assert.property(object, prop, message?) - Asserts object has property prop.
• assert.propertyVal(object, prop, value, message?) - Asserts object[prop] == value.
• assert.sameDeepMembers(set1, set2, message?) - Asserts set1 and set2 have the same deep members.
• assert.sameDeepOrderedMembers(set1, set2, message?) - Asserts set1 and set2 have same deep members in same order.
• assert.sameMembers(set1, set2, message?) - Asserts set1 and set2 have the same members.
• assert.sameOrderedMembers(set1, set2, message?) - Asserts set1 and set2 have same members in same order.
• assert.strictEqual(actual, expected, message?) - Asserts strict equality (===).
• assert.throws(fn, error?, message?) - Asserts fn throws error.
• assert.typeOf(value, type, message?) - Asserts typeof value === type.

Type Testing

• assertType(value) - Asserts a value's type; fails with a type error if incorrect.
• expectTypeOf(value) - Asserts the type of a value at compile time.

Type Matchers (for expectTypeOf & assertType)

• .asserts() - Checks if a function is an assertion function.
• .constructorParameters - Accesses constructor parameters type as a tuple.
• .exclude() - Excludes a type from a union.
• .extract() - Extracts a type from a union.
• .guards() - Checks if a function is a type guard.
• .instance - Accesses the instance type of a class.
• .items - Accesses the type of array items.
• .not - Inverts the meaning of the next type matcher.
• .parameter(index) - Accesses the type of a function parameter at a specific index.
• .parameters - Accesses the parameters type of a function as a tuple.
• .resolves - Accesses the resolved type of a promise.
• .returns - Accesses the return type of a function type.
• .toBeAny() - Checks if the type is any.
• .toBeArray() - Checks if the type is an array.
• .toBeBoolean() - Checks if the type is a boolean.
• .toBeCallableWith(...args) - Checks if a function is callable with given arguments.
• .toBeConstructibleWith(...args) - Checks if a class is constructible with given arguments.
• .toBeFunction() - Checks if the type is a function.
• .toBeNever() - Checks if the type is never.
• .toBeNull() - Checks if the type is null.
• .toBeNullable() - Checks if the type is nullable (or null or undefined).
• .toBeObject() - Checks if the type is an object.
• .toBeString() - Checks if the type is a string.
• .toBeSymbol() - Checks if the type is symbol.
• .toBeUndefined() - Checks if the type is undefined.
• .toBeUnknown() - Checks if the type is unknown.
• .toBeVoid() - Checks if the type is void.
• .toEqualTypeOf() - Checks if types are exactly equal.
• .toExtend() - Checks if the type extends T.
• .toHaveProperty(key, expectedType?) - Checks if an object type has a specific property.
• .toMatchObjectType() - Checks if the type matches an object subset.
• .toMatchTypeOf() - Checks if the type matches a subset of T.

Contributing

Feel free to contribute new snippets or improvements by submitting a pull request to the repository.

License

MIT License