Closed
Description
As briefly discussed here: https://twitter.com/_rsc/status/956888213314068481
I don't see why Go shouldn't cache the results of -coverprofile when running tests, as test coverage shouldn't vary from run to run, given the same set of arguments.
What version of Go are you using (go version)?
go version go1.10rc1 darwin/amd64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env)?
$GOOS="darwin"
$GOARCH="amd64"
What did you do?
Call go test -coverprofile=coverprofile.out ./... multiple times.
What did you expect to see?
Test results cached between runs.
$ go test -coverprofile=coverprofile.out ./...
ok github.com/bbrks/tmp 2.893s coverage: 46.1% of statements
$ go test -coverprofile=coverprofile.out ./...
ok github.com/bbrks/tmp (cached)
What did you see instead?
Test results were not cached between runs.
$ go test -coverprofile=coverprofile.out ./...
ok github.com/bbrks/tmp 2.893s coverage: 46.1% of statements
$ go test -coverprofile=coverprofile.out ./...
ok github.com/bbrks/tmp 2.893s coverage: 46.1% of statements