testing: stream log output in verbose mode

Fixes #24929

Change-Id: Icc426068cd73b75b78001f55e1e5d81ccebbe854
Reviewed-on: https://go-review.googlesource.com/c/go/+/127120
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

Author: jeanbza

src/cmd/go/go_test.go

@@ -4938,35 +4938,31 @@ func TestTestRegexps(t *testing.T) {
 	//	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
-    x_test.go:6: LOG: X running
-        x_test.go:8: LOG: Y running
+    TestX/Y: x_test.go:8: LOG: Y running
 === RUN   TestXX
-    z_test.go:10: LOG: XX running
+    TestXX: z_test.go:10: LOG: XX running
 === RUN   TestX
+    TestX: x_test.go:6: LOG: X running
 === RUN   TestX/Y
-    x_test.go:6: LOG: X running
-        x_test.go:8: LOG: Y running
+    TestX/Y: x_test.go:8: LOG: Y running
 === RUN   TestXX
-    z_test.go:10: LOG: XX running
---- BENCH: BenchmarkX/Y
-    x_test.go:15: LOG: Y running N=1
-    x_test.go:15: LOG: Y running N=100
-    x_test.go:15: LOG: Y running N=10000
-    x_test.go:15: LOG: Y running N=1000000
-    x_test.go:15: LOG: Y running N=100000000
-    x_test.go:15: LOG: Y running N=1000000000
---- BENCH: BenchmarkX/Y
-    x_test.go:15: LOG: Y running N=1
-    x_test.go:15: LOG: Y running N=100
-    x_test.go:15: LOG: Y running N=10000
-    x_test.go:15: LOG: Y running N=1000000
-    x_test.go:15: LOG: Y running N=100000000
-    x_test.go:15: LOG: Y running N=1000000000
---- BENCH: BenchmarkX
-    x_test.go:13: LOG: X running N=1
---- BENCH: BenchmarkXX
-    z_test.go:18: LOG: XX running N=1
+    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, "")

src/testing/benchmark.go

@@ -545,7 +545,11 @@ func (ctx *benchContext) processBench(b *B) {
 		for j := uint(0); j < *count; j++ {
 			runtime.GOMAXPROCS(procs)
 			benchName := benchmarkName(b.name, procs)
-			fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
+
+			// If it's chatty, we've already printed this information.
+			if !b.chatty {
+				fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
+			}
 			// Recompute the running time for all but the first iteration.
 			if i > 0 || j > 0 {
 				b = &B{
@@ -569,6 +573,9 @@ func (ctx *benchContext) processBench(b *B) {
 				continue
 			}
 			results := r.String()
+			if b.chatty {
+				fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
+			}
 			if *benchmarkMemory || b.showAllocResult {
 				results += "\t" + r.MemString()
 			}
@@ -627,6 +634,19 @@ func (b *B) Run(name string, f func(b *B)) bool {
 		// Only process sub-benchmarks, if any.
 		atomic.StoreInt32(&sub.hasSub, 1)
 	}
+
+	if b.chatty {
+		labelsOnce.Do(func() {
+			fmt.Printf("goos: %s\n", runtime.GOOS)
+			fmt.Printf("goarch: %s\n", runtime.GOARCH)
+			if b.importPath != "" {
+				fmt.Printf("pkg: %s\n", b.importPath)
+			}
+		})
+
+		fmt.Println(benchName)
+	}
+
 	if sub.run1() {
 		sub.run()
 	}

src/testing/sub_test.go

@@ -434,6 +434,31 @@ func TestTRun(t *T) {
 			<-ch
 			t.Errorf("error")
 		},
+	}, {
+		// A chatty test should always log with fmt.Print, even if the
+		// parent test has completed.
+		// TODO(deklerk) Capture the log of fmt.Print and assert that the
+		// subtest message is not lost.
+		desc:   "log in finished sub test with chatty",
+		ok:     false,
+		chatty: true,
+		output: `
+		--- FAIL: log in finished sub test with chatty (N.NNs)`,
+		maxPar: 1,
+		f: func(t *T) {
+			ch := make(chan bool)
+			t.Run("sub", func(t2 *T) {
+				go func() {
+					<-ch
+					t2.Log("message1")
+					ch <- true
+				}()
+			})
+			t.Log("message2")
+			ch <- true
+			<-ch
+			t.Errorf("error")
+		},
 	}}
 	for _, tc := range testCases {
 		ctx := newTestContext(tc.maxPar, newMatcher(regexp.MatchString, "", ""))
@@ -521,13 +546,6 @@ func TestBRun(t *T) {
 		chatty: true,
 		output: "--- SKIP: root",
 		f:      func(b *B) { b.SkipNow() },
-	}, {
-		desc:   "skipping with message, chatty",
-		chatty: true,
-		output: `
---- SKIP: root
-    sub_test.go:NNN: skipping`,
-		f: func(b *B) { b.Skip("skipping") },
 	}, {
 		desc:   "chatty with recursion",
 		chatty: true,

src/testing/testing.go

@@ -479,6 +479,9 @@ func (c *common) decorate(s string, skip int) string {
 	buf := new(strings.Builder)
 	// Every line is indented at least 4 spaces.
 	buf.WriteString("    ")
+	if c.chatty {
+		fmt.Fprintf(buf, "%s: ", c.name)
+	}
 	fmt.Fprintf(buf, "%s:%d: ", file, line)
 	lines := strings.Split(s, "\n")
 	if l := len(lines); l > 1 && lines[l-1] == "" {
@@ -662,9 +665,7 @@ func (c *common) log(s string) {
 func (c *common) logDepth(s string, depth int) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	if !c.done {
-		c.output = append(c.output, c.decorate(s, depth+1)...)
-	} else {
+	if c.done {
 		// This test has already finished. Try and log this message
 		// with our parent. If we don't have a parent, panic.
 		for parent := c.parent; parent != nil; parent = parent.parent {
@@ -676,6 +677,12 @@ func (c *common) logDepth(s string, depth int) {
 			}
 		}
 		panic("Log in goroutine after " + c.name + " has completed")
+	} else {
+		if c.chatty {
+			fmt.Print(c.decorate(s, depth+1))
+			return
+		}
+		c.output = append(c.output, c.decorate(s, depth+1)...)
 	}
 }