cmd/go: convert TestCoverageUses*Mode* to script tests

Updates #28387
Updates #30316

Change-Id: I5a1a7870928083a98a76225c428ad4d7263fd832
Reviewed-on: https://go-review.googlesource.com/c/go/+/207610
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/go/go_test.go

@@ -2376,57 +2376,6 @@ func TestCoverageDotImport(t *testing.T) {
 	checkCoverage(tg, data)
 }
 
-// Check that coverage analysis uses set mode.
-// Also check that coverage profiles merge correctly.
-func TestCoverageUsesSetMode(t *testing.T) {
-	skipIfGccgo(t, "gccgo has no cover tool")
-	tooSlow(t)
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.creatingTemp("testdata/cover.out")
-	tg.run("test", "-short", "-cover", "encoding/binary", "errors", "-coverprofile=testdata/cover.out")
-	data := tg.getStdout() + tg.getStderr()
-	if out, err := ioutil.ReadFile("testdata/cover.out"); err != nil {
-		t.Error(err)
-	} else {
-		if !bytes.Contains(out, []byte("mode: set")) {
-			t.Error("missing mode: set")
-		}
-		if !bytes.Contains(out, []byte("errors.go")) {
-			t.Error("missing errors.go")
-		}
-		if !bytes.Contains(out, []byte("binary.go")) {
-			t.Error("missing binary.go")
-		}
-		if bytes.Count(out, []byte("mode: set")) != 1 {
-			t.Error("too many mode: set")
-		}
-	}
-	checkCoverage(tg, data)
-}
-
-func TestCoverageUsesAtomicModeForRace(t *testing.T) {
-	tooSlow(t)
-	if !canRace {
-		t.Skip("skipping because race detector not supported")
-	}
-	skipIfGccgo(t, "gccgo has no cover tool")
-
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.creatingTemp("testdata/cover.out")
-	tg.run("test", "-short", "-race", "-cover", "encoding/binary", "-coverprofile=testdata/cover.out")
-	data := tg.getStdout() + tg.getStderr()
-	if out, err := ioutil.ReadFile("testdata/cover.out"); err != nil {
-		t.Error(err)
-	} else {
-		if !bytes.Contains(out, []byte("mode: atomic")) {
-			t.Error("missing mode: atomic")
-		}
-	}
-	checkCoverage(tg, data)
-}
-
 func TestCoverageSyncAtomicImport(t *testing.T) {
 	skipIfGccgo(t, "gccgo has no cover tool")
 	tooSlow(t)

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

+env GO111MODULE=off
+
+# Coverage analysis should use 'set' mode by default,
+# and should merge coverage profiles correctly.
+
+[short] skip
+[gccgo] skip # gccgo has no cover tool
+
+go test -short -cover encoding/binary errors -coverprofile=$WORK/cover.out
+! stderr '[^0-9]0\.0%'
+! stdout '[^0-9]0\.0%'
+
+grep -count=1 '^mode: set$' $WORK/cover.out
+grep 'errors\.go' $WORK/cover.out
+grep 'binary\.go' $WORK/cover.out
+
+[!race] stop
+
+go test -short -race -cover encoding/binary errors -coverprofile=$WORK/cover.out
+! stderr '[^0-9]0\.0%'
+! stdout '[^0-9]0\.0%'
+
+grep -count=1 '^mode: atomic$' $WORK/cover.out
+grep 'errors\.go' $WORK/cover.out
+grep 'binary\.go' $WORK/cover.out