@vitest/expect

Vitest 2.0 is here! This release page lists all changes made to the project during the beta. For the migration guide, please refer to the documentation.

Breaking Changes

• breaking

  Simplify mock function generic types and align with jest - by @hi-ogawa

• breaking

  Remove --segfault-retry

  • This flag was introduced to combat threads segfaults. Our current recommendation is to use the new default forks pool instead.

• breaking

  Run suite hooks in a stack

  • This feels like a more sensible default. Especially with the new onTestFinished hook. This can make your tests run a little bit slower.

• breaking

  Enable coverage.ignoreEmptyLines by default

  • ⚠️ This change may cause significant differences in your coverage results compared to Vitest v1. These changes are expected as coverage reporting is now more accurate. See #5423 for more details.

• breaking

  Add correct location and snapshot fields in json reporter

  • Previously, the location field pointed to the error location instead of the test location. Now it is aligned with jest and contains the line and column of a test function, but requires includeTaskLocation to be enabled.

• breaking

  Update dependency chai to v5 - by renovate[bot] and @sheremet-va in #5135

• breaking

  Remove watchExclude

• breaking

  Change default pool to 'forks'

  • This change is done for compatibility issues

  • This pool may be slightly slower than previous threads pool: vitest.dev/guide/improving-performance.html

• breaking

  --merge-reports to support coverage

• breaking

  Add promise-based return assertions, do not auto-resolve returned promises

  • ⚠️ Vitest no longer unwraps promises in spy.mock.returns. If the function is async or returns a promise, it will always succeed and have a Promise in results. To make migration easier, we introduced spy.mock.settledResults that unwraps promises and expect().toHaveResolved() matcher that accepts unwrapped value.

• breaking

  Do not exit process if global setup has failed

• breaking

  Don't exit process if config failed

• breaking

  Add meta to json output

• breaking

  Rename indexScripts to orchestratorScripts in the browser config

• breaking

  Add "vitest list" API to print collected tests without running them

  • ⚠️ This changes the custom pool API - now requires collectTests method alongside runTests.

• breaking

  Remove the empty suite from the runner

• breaking

  Support concurrent suites - by @hi-ogawa

• breaking

  Support overriding exclude in coverage

  • ⚠️ Vitest coverage no longer adds test files to exclude patterns if coverage.exclude was overridden in the config. Add your test patterns manually, or merge your overrides with default ones: ['**/my-pattern.js', ...coverageConfigDefaults.exclude]. See vitest.dev/config/ for an example.

• breaking

  api: Remove process.exit if workspace project failed to be created

• breaking

  api: Don't call process.exit manually

Features

• browser: 🌐 This release lays the groundwork for the next iteration of Vitest Browser Mode. You can read more about our future plans at github.com/vitest-dev/vitest/discussions/5828

• browser: Add commands to communicate betweens server and the browser

• browser: Do not reload the page during watch mode

• browser: Support changing the viewport

• browser: Add browser iframe mouse interaction

• browser: Support click event

• browser: Rename none provider to preview, make it default

• browser: Run tests in parallel in headless mode, add page.screenshot method

• browser: Implement several userEvent methods, add fill and dragAndDrop events

• browser: Introduce expect.dom method and bundle jest-dom matchers with @vitest/browser

• browser: Expose CDP in the browser

• browser: Add "init" command for browser tests

• browser: Add an option to take screenshots if the browser test fails

• browser: Add tripleClick to interactive api

• browser: Playwright provider doesn't allow resizing the browser viewport

• Pretty print diffs coming from cause

• Allow import statement as vi.mock path for better IDE support

• removed

  Remove deprecated options

• Add blob reporter

  • ✅ Run Vitest in separate processes with --reporter=blob flag to generate reports and combine them with vitest --merge-reports later!

• Add expect.poll utility

• Add browser.ui option

• Add median to --output-json

• Allow augmenting config.test.env

• Implement module mocking in browser mode

• Allow configuring expect options in the config

• Add an option to print console stack trace

• Add browser frame to UI

• Image type add bmp - by btea in #5921

• Add an option to return base64 from page.screenshot

• Expose parseAst, parseAstAsync from vite

• config: Allow percentage value for workers option

• runner: Implement test.for

• spy: Collect mock.contexts

• ui: Render tests in a tree

• ui: Load module graph on tab selection

• ui: Replace navigation tree with test explorer

• ui: Add initializing explorer logic

• ui: Add action to explorer item to show the test/suite line in the source code tab

• ws-client: Allow change reactive for state, filesMap and idMap

Bug Fixes

• Print console statements in vmThreads

• Repeatable --exclude option

• Remove browser.fileParallelism

• Install UI icons

• Vi.waitFor/vi.waitUntil interval is now cleared after it times out

• ToJSON recursive error serialization

• Print error properties only in verbose reporter

• Use TTY reporter when running in Deno

• Don't override uppercase

• Clear screen and scrollback on iTerm2

• Include pretty-format in @vitest/runner for optimization on npm

• Transpile esnext to node18 to support newest JS and TS features

• api: Correct project.provide type

• browser: Display UI

• browser: Browser actions icons colors

• browser: Restore the original viewport when unselecting the preset viewport

• browser: Don't get stuck after the manual page refresh

• browser: Use iframe id instead of calculating it from filenames

• browser: Always clean up iframes on rerun

• browser: Support @testing-library/vue in browser mode out of the box

• browser: Print correct transformed module graph

• browser: Use preview provider when running in StackBlitz

• browser: Specify entries for correct deps optimization

• browser: Allow iframe to load even if there is a custom CSP header

• browser: Don't optimize Vitest dependencies

• browser: Set server.open to false and move error handling after init

• browser: Show correct prepare time

• browser: Resolve coverage.reporter from string values

• browser: Correctly update inline snapshot if changed

• browser: Remove "util" warning

• browser: Remove hacky retry

• browser: Make userEvent more stable when running in parallel

• browser: Print screenshot path alongside the test error message

• browser: Print correct stack trace in source files

• browser: Correctly mock optimized cjs dependencies

• browser: Support shadow root and svg elements

• coverage: Clean up empty coverage reports directory

• coverage: thresholds.autoUpdate to support mergeConfig

• coverage: Pass thresholds errors to stderr of startVitest()

• coverage: Exclude bench files from coverage

• coverage: Vite to ignore dynamic import of provider

• coverage: Istanbul to support import attributes

• coverage: Remove work-around for implicit else

• deps: Update vulnerable test-exclude to v7

• expect: Fix immutable.js iterable equality

• forks: Resolve poolOptions.<name>.isolate from forks options

• runner: Ensure inner suite { sequential: true } correctly overrides outer suite { concurrent: true }

• runner: Ensure test.each print -0 and -NaN properly

• snapshot: Fix toMatchFileSnapshot with empty file

• spy: Correctly track constructor's "this" type

• types: Mark pool options as not available in project config

• ui: Show correct module graph and project name in a Vitest workspace

• ui: Update running todo tests inside todo suites (each)

• ui: FileDetails title status icon not being updated

• ui, browser: Disable mouse events when resizing main navigation panel

• utils: Produce valid snapshot names

• utils: Fix color util maximum call stack error

• utils: Package exports

• vite-node: Expose all envs from .env file, not just with a prefix VITE_

• vitest: Expose provide to the public API

• vitest: Cache fs code only for forks pool

• vitest: Allow testing unandled rejection/exception

• vitest: Show all failed tests when rerunning a test