cmd/go: convert tests using testdata/src/(xtestonly|cgotest) to script framework

Part of converting all tests to script framework to improve
test parallelism.

Updates #36320
Updates #17751

Change-Id: I3465cad1b0ba0d912067429146f1cb0668d5aa6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/214284
Reviewed-by: Jay Conrod <jayconrod@google.com>

src/cmd/go/go_test.go

@@ -1131,15 +1131,6 @@ func TestVersionControlErrorMessageIncludesCorrectDirectory(t *testing.T) {
 	tg.grepStderr(regexp.QuoteMeta(quoted), "go get -u error does not mention shadow/root1/src/foo")
 }
 
-func TestInstallFailsWithNoBuildableFiles(t *testing.T) {
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
-	tg.setenv("CGO_ENABLED", "0")
-	tg.runFail("install", "cgotest")
-	tg.grepStderr("build constraints exclude all Go files", "go install cgotest did not report 'build constraints exclude all Go files'")
-}
-
 // Issue 21895
 func TestMSanAndRaceRequireCgo(t *testing.T) {
 	if !canMSan && !canRace {
@@ -1254,19 +1245,6 @@ func TestGoListCmdOnlyShowsCommands(t *testing.T) {
 	}
 }
 
-func TestGoListDedupsPackages(t *testing.T) {
-	tg := testgo(t)
-	defer tg.cleanup()
-	// TODO: tg.parallel()
-	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
-	tg.run("list", "xtestonly", "./testdata/src/xtestonly/...")
-	got := strings.TrimSpace(tg.getStdout())
-	const want = "xtestonly"
-	if got != want {
-		t.Errorf("got %q; want %q", got, want)
-	}
-}
-
 func TestGoListDeps(t *testing.T) {
 	tg := testgo(t)
 	defer tg.cleanup()
@@ -2131,14 +2109,6 @@ func TestListTemplateContextFunction(t *testing.T) {
 	}
 }
 
-func TestGoTestXtestonlyWorks(t *testing.T) {
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
-	tg.run("clean", "-i", "xtestonly")
-	tg.run("test", "xtestonly")
-}
-
 func TestGoTestBuildsAnXtestContainingOnlyNonRunnableExamples(t *testing.T) {
 	tg := testgo(t)
 	defer tg.cleanup()

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

@@ -0,0 +1,11 @@
+env CGO_ENABLED=0
+
+! go install cgotest
+stderr 'build constraints exclude all Go files'
+
+-- cgotest/m.go --
+package cgotest
+
+import "C"
+
+var _ C.int

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

@@ -0,0 +1,30 @@
+# Setup
+mkdir $WORK/tmp/testdata/src/xtestonly
+cp f.go $WORK/tmp/testdata/src/xtestonly/f.go
+cp f_test.go $WORK/tmp/testdata/src/xtestonly/f_test.go
+env GOPATH=$WORK/tmp/testdata
+cd $WORK
+
+# Check output of go list to ensure no duplicates
+go list xtestonly ./testdata/src/xtestonly/...
+cmp stdout $WORK/gopath/src/wantstdout
+
+-- wantstdout --
+xtestonly
+-- 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)
+	}
+}

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

@@ -0,0 +1,23 @@
+[short] skip
+
+go test xtestonly
+! stdout '^ok.*\[no tests to run\]'
+stdout '^ok'
+
+-- xtestonly/f.go --
+package xtestonly
+
+func F() int { return 42 }
+-- xtestonly/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)
+	}
+}

src/cmd/go/testdata/src/cgotest/m.go

@@ -1,5 +0,0 @@
-package cgotest
-
-import "C"
-
-var _ C.int

src/cmd/go/testdata/src/xtestonly/f.go

@@ -1,3 +0,0 @@
-package xtestonly
-
-func F() int { return 42 }

src/cmd/go/testdata/src/xtestonly/f_test.go

@@ -1,12 +0,0 @@
-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)
-	}
-}