env GO111MODULE=on
go mod init foo
go test
stdout ^ok\s+foo
env GO111MODULE=off
go test
stdout ^ok\s+
! stdout ^ok\s+(cache)$

-- main_test.go --
package main

import "testing"

[short] skip
[!cgo] skip
[compiler:gccgo] skip # gccgo has no cover tool

# Test coverage on cgo code.

go test -short -cover cgocover
stdout  'coverage:.*[1-9][0-9.]+%'
! stderr '[^0-9]0\.0%'

-- go.mod --
module cgocover

go 1.16
-- p.go --
package p

/*
void
f(void)
{
}
*/
import "C"

var b bool

func F() {
	if b {
		for {
		}
	}
	C.f()
}
-- p_test.go --

[short] skip
[!cgo] skip
[compiler:gccgo] skip # gccgo has no cover tool

# Test coverage on cgo code. This test case includes an
# extra empty non-cgo file in the package being checked.

go test -short -cover cgocover4
stdout  'coverage:.*[1-9][0-9.]+%'
! stderr '[^0-9]0\.0%'

-- go.mod --
module cgocover4

go 1.16
-- notcgo.go --
package p
-- p.go --
package p

/*
void
f(void)
{
}
*/
import "C"

# Relative imports in command line package

env GO111MODULE=off

# Run tests outside GOPATH.
env GOPATH=$WORK/tmp

go test ./testimport/p.go ./testimport/p_test.go ./testimport/x_test.go
stdout '^ok'

-- testimport/p.go --
package p

func F() int { return 1 }
-- testimport/p1/p1.go --
package p1

func F() int { return 1 }
-- testimport/p2/p2.go --
package p2

func F() int { return 1 }
-- testimport/p_test.go --

env GO111MODULE=off

[short] skip

go test -coverpkg=all -covermode=atomic x
stdout ok[\s\S]+?coverage

[!race] stop

go test -coverpkg=all -race x
stdout ok[\s\S]+?coverage

-- x/x.go --
package x

import _ "sync/atomic"

func F() {}

-- x/x_test.go --
package x

import "testing"

	f.writeCount = 0
	f.writeLimit = lim
	f.slws = slicewriter.WriteSeeker{}
}

func writeStressTest(tag string, testf func(testf *failingWriter) error) {
	// Invoke the function initially without the write limit
	// set, to capture the number of writes performed.
	fw := &failingWriter{writeLimit: -1}
	testf(fw)

	// Now that we know how many writes are going to happen, run the

[short] skip

go test xtestonly
! stdout '^ok.*\[no tests to run\]'
stdout '^ok'

-- go.mod --
module xtestonly

go 1.16
-- f.go --
package xtestonly

func F() int { return 42 }
-- f_test.go --
package xtestonly_test

import (
	"testing"
	"xtestonly"
)

func TestF(t *testing.T) {
	if x := xtestonly.F(); x != 42 {
		t.Errorf("f.F() = %d, want 42", x)
	}

env GO111MODULE=off

# Issue 23882

[short] skip

go test -coverpkg=all x
stdout ok[\s\S]+?coverage

[!race] stop

go test -coverpkg=all -race x
stdout ok[\s\S]+?coverage

-- x/x.go --
package x
import _ "runtime"
func F() {}

-- x/x_test.go --
package x
import "testing"

[short] skip
[!cgo] skip
[compiler:gccgo] skip # gccgo has no cover tool

# Test cgo coverage with an external test.

go test -short -cover cgocover2
stdout  'coverage:.*[1-9][0-9.]+%'
! stderr '[^0-9]0\.0%'

-- go.mod --
module cgocover2

go 1.16
-- p.go --
package p

/*
void
f(void)
{
}
*/
import "C"

var b bool

func F() {
	if b {
		for {
		}
	}
	C.f()
}

[short] skip
[!cgo] skip
[compiler:gccgo] skip # gccgo has no cover tool

# Test coverage on cgo code. This test case has an external
# test that tests the code and an in-package test file with
# no test cases.

go test -short -cover cgocover3
stdout  'coverage:.*[1-9][0-9.]+%'
! stderr '[^0-9]0\.0%'

-- go.mod --
module cgocover3

go 1.16
-- p.go --
package p

/*
void
f(void)
{
}
*/
import "C"