Preserve chained vitest helpers like it.describe.each through the it proxy - #6444
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mikearnaldi merged 1 commit intoJul 18, 2026
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Closes #6348.
makeItProxyinpackages/vitest/src/internal/internal.tsreturnedvalue.bind(target)for every function property accessed through theitproxy.Function.prototype.bindproduces a fresh function without the original's own properties, and that is exactly where vitest attaches its static helpers (each,skip,only, etc.). As a result, chained access likeit.describe.each(...)orit.skip.each(...)threwTypeError: it.describe.each is not a function.This returns the property as is instead of a bound copy. Removing the bind is safe: vitest's chain functions ignore dynamic
thisand invoke the underlying collector with a context captured in a closure, while the helpers that do readthis(each,for,skipIf,runIf) still resolve correctly because the proxy forwards every lookup it does not override, including vitest's internal context symbol, to the target. Before the proxy was introduced,makeMethodsusedObject.assign(it, overrides)on the vitestitdirectly, so chained helpers worked natively; this restores those semantics. As a side effect, property access no longer allocates a bound function each time.Adds regression tests for
it.describe.each(the reproduction from the issue, with a nestedit.effect) andit.skip.each, both verified to fail against the previous implementation.This supersedes Effect-TS/effect-smol#2302 by @truffle-dev, which proposed this same fix, and Effect-TS/effect-smol#2344 by @SAY-5, both closed in the V4 repository migration. Happy to close this in favor of either author if they would prefer to resubmit their own port.