cmd/go: convert TestCoverageImportMainLoop and TestGoTestMain

Convert these two tests to the script framework.

Updates #17751
Updates #36320

Change-Id: I9cc14360fab949dab91f9e5e667be85002ef5926
Reviewed-on: https://go-review.googlesource.com/c/go/+/212811
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

src/cmd/go/go_test.go

@@ -2144,17 +2144,6 @@ func TestCoverageNoStatements(t *testing.T) {
 	tg.grepStdout("[no statements]", "expected [no statements] for pkg4")
 }
 
-func TestCoverageImportMainLoop(t *testing.T) {
-	skipIfGccgo(t, "gccgo has no cover tool")
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
-	tg.runFail("test", "importmain/test")
-	tg.grepStderr("not an importable package", "did not detect import main")
-	tg.runFail("test", "-cover", "importmain/test")
-	tg.grepStderr("not an importable package", "did not detect import main")
-}
-
 func TestCoverageErrorLine(t *testing.T) {
 	skipIfGccgo(t, "gccgo has no cover tool")
 	tooSlow(t)
@@ -2587,21 +2576,6 @@ func TestGoTestMainAsNormalTest(t *testing.T) {
 	tg.grepBoth(okPattern, "go test did not say ok")
 }
 
-func TestGoTestMainTwice(t *testing.T) {
-	if testing.Short() {
-		t.Skip("Skipping in short mode")
-	}
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.makeTempdir()
-	tg.setenv("GOCACHE", tg.tempdir)
-	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
-	tg.run("test", "-v", "multimain")
-	if strings.Count(tg.getStdout(), "notwithstanding") != 2 {
-		t.Fatal("tests did not run twice")
-	}
-}
-
 func TestGoTestXtestonlyWorks(t *testing.T) {
 	tg := testgo(t)
 	defer tg.cleanup()

src/cmd/go/testdata/script/cover_import_main_loop.txt

+[gccgo] skip # gccgo has no cover tool
+
+! go test -n importmain/test
+stderr 'not an importable package' # check that import main was detected
+! go test -n -cover importmain/test
+stderr 'not an importable package' # check that import main was detected
+
+-- importmain/ismain/main.go --
+package main
+
+import _ "importmain/test"
+
+func main() {}
+-- importmain/test/test.go --
+package test
+-- importmain/test/test_test.go --
+package test_test
+
+import "testing"
+import _ "importmain/ismain"
+
+func TestCase(t *testing.T) {}

src/cmd/go/testdata/src/multimain/multimain_test.go → src/cmd/go/testdata/script/test_main_twice.txt

+[short] skip
+
+env GOCACHE=$TMPDIR
+go test -v multimain
+stdout -count=2 notwithstanding # check tests ran twice
+
+-- multimain/multimain_test.go --
 package multimain_test
 
 import "testing"

src/cmd/go/testdata/src/importmain/ismain/main.go

-package main
-
-import _ "importmain/test"
-
-func main() {}

src/cmd/go/testdata/src/importmain/test/test.go

-package test

src/cmd/go/testdata/src/importmain/test/test_test.go

-package test_test
-
-import "testing"
-import _ "importmain/ismain"
-
-func TestCase(t *testing.T) {}