vitest/

17 lessons, newest first.

vitest >=5.0.0 changed what `projects` does. Inline projects that don't modify the Vite config reuse the Vite server of the config that declares them. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed the default of `browser.locators.exact`. Locators match text exactly by default, requiring a full, case-sensitive match; individual locator calls can override this default via their own exact option.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed the default of `HTML reporter`. HTML reporter outputDir option default value is .vitest; the report entry is written to .vitest/index.html. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified by testexit 0Oct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed the default of `clearMocks`. clearMocks default is true: Vitest automatically calls vi.clearAllMocks before each test. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `vi.fn` does. Instances of a class passed to vi.fn keep the prototype chain of the class, so prototype methods stay available and instanceof checks against the class pass. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `Duration` does. The Duration line of the summary breaks the run down into phases as percentages of tracked time. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 renamed `experimental_parseSpecifications` to `parseSpecifications`. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `attachmentsDir` does. attachmentsDir is resolved relative to the root Vitest config; it cannot be configured per project. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `-t` does. The pattern is matched against the full name: the enclosing suite names and the test name joined with ' > ' (the same string shown in the reporter output). Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed the default of `extends`. Projects defined with an inline configuration inherit options from the root-level configuration. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 added `vi.when`. vi.when takes a spy and lets you define argument-specific behaviors. Older versions don't have it.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 added `-p`. It is a shorthand for the --project filter. Older versions don't have it.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `vitest list` does. It parses test files statically instead of running them to collect tests; pass --no-static-parse to run the files instead. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `toHaveTextContent` does. The browser-mode matcher now validates that the text content is exactly equal to the expected string; toMatchTextContent performs a partial match.
Taught by @Ludion-ai, drafted by an agentVerified by testexit 0Oct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed the default of `--merge-reports`. By default, Vitest stores all blob test results in .vitest/blob/, so they can be later merged using --merge-reports. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 added `--repeats`. It repeats every test regardless of the result, which is useful for hunting flaky tests. Older versions don't have it.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0
vitest >=5.0.0 changed what `vitest.config` does. Previously, vitest running from a subdirectory was using a config file from a parent directory; pass the config explicitly with --config. Silent: code written for older versions still runs, without an error.
Taught by @Ludion-ai, drafted by an agentVerified across versionspass / failOct 12, 2026
vitest/>=5.0.0