cmd/go: convert TestTestRegexps to the script framework

It's hard to convert this one exactly because I don't think
we can guarantee that the grep command exists to filter stdout,
so I've tried to replicate the intent of the test.

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

Updates #36320
Updates #17751

Change-Id: Ib593799ef7634ce12efb3ff357eb34475e2ea321
Reviewed-on: https://go-review.googlesource.com/c/go/+/213130
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

src/cmd/go/go_test.go

@@ -4086,60 +4086,6 @@ func main() {}`)
 	}))
 }
 
-func TestTestRegexps(t *testing.T) {
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
-	tg.run("test", "-cpu=1", "-run=X/Y", "-bench=X/Y", "-count=2", "-v", "testregexp")
-	var lines []string
-	for _, line := range strings.SplitAfter(tg.getStdout(), "\n") {
-		if strings.Contains(line, "=== RUN") || strings.Contains(line, "--- BENCH") || strings.Contains(line, "LOG") {
-			lines = append(lines, line)
-		}
-	}
-
-	// Important parts:
-	//	TestX is run, twice
-	//	TestX/Y is run, twice
-	//	TestXX is run, twice
-	//	TestZ is not run
-	//	BenchmarkX is run but only with N=1, once
-	//	BenchmarkXX is run but only with N=1, once
-	//	BenchmarkX/Y is run in full, twice
-	want := `=== RUN   TestX
-    TestX: x_test.go:6: LOG: X running
-=== RUN   TestX/Y
-    TestX/Y: x_test.go:8: LOG: Y running
-=== RUN   TestXX
-    TestXX: z_test.go:10: LOG: XX running
-=== RUN   TestX
-    TestX: x_test.go:6: LOG: X running
-=== RUN   TestX/Y
-    TestX/Y: x_test.go:8: LOG: Y running
-=== RUN   TestXX
-    TestXX: z_test.go:10: LOG: XX running
-    BenchmarkX: x_test.go:13: LOG: X running N=1
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=10000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100000000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=10000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100000000
-    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000000
-    BenchmarkXX: z_test.go:18: LOG: XX running N=1
-`
-
-	have := strings.Join(lines, "")
-	if have != want {
-		t.Errorf("reduced output:<<<\n%s>>> want:<<<\n%s>>>", have, want)
-	}
-}
-
 func TestListTests(t *testing.T) {
 	tooSlow(t)
 	var tg *testgoData

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

+go test -cpu=1 -run=X/Y -bench=X/Y -count=2 -v testregexp
+
+# Test the following:
+
+#	TestX is run, twice
+stdout -count=2 '^=== RUN   TestX$'
+stdout -count=2 '^    TestX: x_test.go:6: LOG: X running$'
+
+#	TestX/Y is run, twice
+stdout -count=2 '^=== RUN   TestX/Y$'
+stdout -count=2 '^    TestX/Y: x_test.go:8: LOG: Y running$'
+
+#	TestXX is run, twice
+stdout -count=2 '^=== RUN   TestXX$'
+stdout -count=2 '^    TestXX: z_test.go:10: LOG: XX running'
+
+#	TestZ is not run
+! stdout '^=== RUN   TestZ$'
+
+#	BenchmarkX is run but only with N=1, once
+stdout -count=1 '^    BenchmarkX: x_test.go:13: LOG: X running N=1$'
+! stdout '^    BenchmarkX: x_test.go:13: LOG: X running N=10$'
+
+#	BenchmarkXX is run but only with N=1, once
+stdout -count=1 '^    BenchmarkXX: z_test.go:18: LOG: XX running N=1$'
+! stdout  '^    BenchmarkXX: z_test.go:18: LOG: XX running N=10$'
+
+#	BenchmarkX/Y is run in full, twice
+stdout -count=2 '    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=10000\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=100000000\n    BenchmarkX/Y: x_test.go:15: LOG: Y running N=1000000000'
+
+-- testregexp/x_test.go --
+package x
+
+import "testing"
+
+func TestX(t *testing.T) {
+	t.Logf("LOG: X running")
+	t.Run("Y", func(t *testing.T) {
+		t.Logf("LOG: Y running")
+	})
+}
+
+func BenchmarkX(b *testing.B) {
+	b.Logf("LOG: X running N=%d", b.N)
+	b.Run("Y", func(b *testing.B) {
+		b.Logf("LOG: Y running N=%d", b.N)
+	})
+}
+-- testregexp/z_test.go --
+package x
+
+import "testing"
+
+func TestZ(t *testing.T) {
+	t.Logf("LOG: Z running")
+}
+
+func TestXX(t *testing.T) {
+	t.Logf("LOG: XX running")
+}
+
+func BenchmarkZ(b *testing.B) {
+	b.Logf("LOG: Z running N=%d", b.N)
+}
+
+func BenchmarkXX(b *testing.B) {
+	b.Logf("LOG: XX running N=%d", b.N)
+}
\ No newline at end of file

src/cmd/go/testdata/src/testregexp/x_test.go

-package x
-
-import "testing"
-
-func TestX(t *testing.T) {
-	t.Logf("LOG: X running")
-	t.Run("Y", func(t *testing.T) {
-		t.Logf("LOG: Y running")
-	})
-}
-
-func BenchmarkX(b *testing.B) {
-	b.Logf("LOG: X running N=%d", b.N)
-	b.Run("Y", func(b *testing.B) {
-		b.Logf("LOG: Y running N=%d", b.N)
-	})
-}

src/cmd/go/testdata/src/testregexp/z_test.go

-package x
-
-import "testing"
-
-func TestZ(t *testing.T) {
-	t.Logf("LOG: Z running")
-}
-
-func TestXX(t *testing.T) {
-	t.Logf("LOG: XX running")
-}
-
-func BenchmarkZ(b *testing.B) {
-	b.Logf("LOG: Z running N=%d", b.N)
-}
-
-func BenchmarkXX(b *testing.B) {
-	b.Logf("LOG: XX running N=%d", b.N)
-}