Change "EventuallyWithT" condition acceptance to no-errors raised

[arikkfir]

Summary

This change updates the EventuallyWithT assertion variants (regular, formatted, requirement) to consider a condition as "met" if no assertion errors were raised in a tick.

This allows to write easier conditions which simply contain assertions, without needing to return a bool. The equivalent of a condition returning true in the previous implementation would be a a condition with a single "assert.True(..)" call.

Changes

• Update all EventuallyWithT variants to consider a condition as "met" if the mocked T (assert.CollectT) has no errors.

Motivation

It's easier to write conditions that only use assertions than conditions that both assert and also need to evaluate the condition result, as the result is often dependent on whether any of the assertions failed. For instance, if an assertion failed, but the condition function returns true, the collection assertions will not fail the test.

Example usage (if applicable)

externalValue := false
go func() {
	time.Sleep(8*time.Second)
	externalValue = true
}()
assert.EventuallyWithTf(t, func(c *assert.CollectT) {
	// add assertions as needed; any assertion failure will fail the current tick
	assert.True(c, externalValue, "expected 'externalValue' to be true")
}, 1*time.Second, 10*time.Second, "external state has not changed to 'true'; still: %v", externalState)

Related issues

Related to stretchr#902 and stretchr#1264

[tobikris]

Great idea, thank you very much!