stretchr/testify · error

Reset() is deprecated

Error message

Reset() is deprecated

What it means

CollectT.Reset() (assert/assertions.go:2065) is an unconditionally panicking stub marked Deprecated. It was an internal helper that was accidentally exported and later removed; calling it always panics with this message. CollectT is the error-collecting TestingT used by EventuallyWithT.

Source

Thrown at assert/assertions.go:2066

}

// Helper is like [testing.T.Helper] but does nothing.
func (CollectT) Helper() {}

// Errorf collects the error.
func (c *CollectT) Errorf(format string, args ...interface{}) {
	c.errors = append(c.errors, fmt.Errorf(format, args...))
}

// FailNow stops execution by calling runtime.Goexit.
func (c *CollectT) FailNow() {
	c.fail()
	runtime.Goexit()
}

// Deprecated: That was a method for internal usage that should not have been published. Now just panics.
func (*CollectT) Reset() {
	panic("Reset() is deprecated")
}

// Deprecated: That was a method for internal usage that should not have been published. Now just panics.
func (*CollectT) Copy(TestingT) {
	panic("Copy() is deprecated")
}

func (c *CollectT) fail() {
	if !c.failed() {
		c.errors = []error{} // Make it non-nil to mark a failure.
	}
}

func (c *CollectT) failed() bool {
	return c.errors != nil
}

// EventuallyWithT asserts that given condition will be met in waitFor time,

View on GitHub (pinned to 001eb7946b)

Solutions

1. Remove the Reset() call — CollectT is meant to be used once per EventuallyWithT run, not reset.
2. If you need a fresh error collector, allocate a new CollectT instead of resetting an existing one.
3. Search the codebase for '.Reset()' on CollectT values and delete those lines.

Example fix

// before
collectT := &assert.CollectT{}
assert.EventuallyWithT(collectT, func(*assert.CollectT) bool { ... }, ...)
collectT.Reset()
// after
collectT := &assert.CollectT{}
assert.EventuallyWithT(collectT, func(*assert.CollectT) bool { ... }, ...)

// Static prevention: search & remove collectT.Reset() calls.
// No runtime guard is meaningful — Reset() always panics.

// There is no recovery pattern; the method is intentionally gone.
// Delete all .Reset() calls on *assert.CollectT values.

When it happens

Trigger: Calling collectT.Reset() on a *assert.CollectT instance — typically copy-pasted from old testify examples or a pre-1.8 codebase that used Reset to clear collected errors between iterations.

Common situations: Upgrading testify past the version where Reset was deprecated; following an outdated tutorial or Stack Overflow answer; generated test scaffolding that still calls Reset.

Related errors

• Copy() is deprecated
• test failed and t is missing `FailNow()`
• cannot use Func in expectations. Use mock.AnythingOfType("%T
• not before calls must be created with Mock.On()
• assert: arguments: %s is not a func

AI-assisted analysis of stretchr/testify@001eb7946b (2026-08-04). Data as JSON: /data/errors/174f713365f24bc6.json. Report an issue: GitHub.