analysis/passes: report testing.Fatal* FailNow Skip* misuse in gorout…

…ines

Adds an analyzer to report an error if any tests or benchmarks
have any *Fatal, FailNow, Skip* misuses in goroutines which are
forbidden by the package testing, since those functions terminate
the entire benchmark/test yet ideally one goroutine exiting shouldn't
affect the entire benchmark/test.

This first pass only works for plain goroutines and doesn't yet work
with b.RunParallel. That'll be added in a subsequent CL after this
one is reviewed and merged.

Updates #5746

Change-Id: Ia47e5c9fd96ceced1ae9834b94f529f6ae2edaaa
Reviewed-on: https://go-review.googlesource.com/c/tools/+/212920
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>

go/analysis/passes/testinggoroutine/testdata/src/a/a.go

@@ -0,0 +1,261 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+import (
+	"log"
+	"sync"
+	"testing"
+)
+
+func TestBadFatalf(t *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			t.Fatalf("TestFailed: id = %v\n", id) // want "call to .+T.+Fatalf from a non-test goroutine"
+		}(i)
+	}
+}
+
+func TestOKErrorf(t *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			t.Errorf("TestFailed: id = %v\n", id)
+		}(i)
+	}
+}
+
+func BenchmarkBadFatalf(b *testing.B) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < b.N; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			b.Fatalf("TestFailed: id = %v\n", id) // want "call to .+B.+Fatalf from a non-test goroutine"
+		}(i)
+	}
+}
+
+func TestBadFatal(t *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			t.Fatal("TestFailed") // want "call to .+T.+Fatal from a non-test goroutine"
+		}(i)
+	}
+}
+
+func BenchmarkBadFatal(b *testing.B) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < b.N; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			b.Fatal("TestFailed") // want "call to .+B.+Fatal from a non-test goroutine"
+		}(i)
+	}
+}
+
+func BenchmarkOKErrorf(b *testing.B) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < b.N; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+			b.Errorf("TestFailed: %d", i)
+		}(i)
+	}
+}
+
+func BenchmarkBadFatalGoGo(b *testing.B) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < b.N; i++ {
+		wg.Add(1)
+		go func(id int) {
+			go func() {
+				defer wg.Done()
+				b.Fatal("TestFailed") // want "call to .+B.+Fatal from a non-test goroutine"
+			}()
+		}(i)
+	}
+
+	if false {
+		defer b.Fatal("here")
+	}
+
+	if true {
+		go func() {
+			b.Fatal("in here") // want "call to .+B.+Fatal from a non-test goroutine"
+		}()
+	}
+
+	func() {
+		func() {
+			func() {
+				func() {
+					go func() {
+						b.Fatal("Here") // want "call to .+B.+Fatal from a non-test goroutine"
+					}()
+				}()
+			}()
+		}()
+	}()
+
+	_ = 10 * 10
+	_ = func() bool {
+		go b.Fatal("Failed") // want "call to .+B.+Fatal from a non-test goroutine"
+		return true
+	}
+
+	defer func() {
+		go b.Fatal("Here") // want "call to .+B.+Fatal from a non-test goroutine"
+	}()
+}
+
+func BenchmarkBadSkip(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		if i == 100 {
+			go b.Skip("Skipping") // want "call to .+B.+Skip from a non-test goroutine"
+		}
+		if i == 22 {
+			go func() {
+				go func() {
+					b.Skip("Skipping now") // want "call to .+B.+Skip from a non-test goroutine"
+				}()
+			}()
+		}
+	}
+}
+
+func TestBadSkip(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		if i == 100 {
+			go t.Skip("Skipping") // want "call to .+T.+Skip from a non-test goroutine"
+		}
+		if i == 22 {
+			go func() {
+				go func() {
+					t.Skip("Skipping now") // want "call to .+T.+Skip from a non-test goroutine"
+				}()
+			}()
+		}
+	}
+}
+
+func BenchmarkBadFailNow(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		if i == 100 {
+			go b.FailNow() // want "call to .+B.+FailNow from a non-test goroutine"
+		}
+		if i == 22 {
+			go func() {
+				go func() {
+					b.FailNow() // want "call to .+B.+FailNow from a non-test goroutine"
+				}()
+			}()
+		}
+	}
+}
+
+func TestBadFailNow(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		if i == 100 {
+			go t.FailNow() // want "call to .+T.+FailNow from a non-test goroutine"
+		}
+		if i == 22 {
+			go func() {
+				go func() {
+					t.FailNow() // want "call to .+T.+FailNow from a non-test goroutine"
+				}()
+			}()
+		}
+	}
+}
+
+func TestBadWithLoopCond(ty *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer ty.Fatalf("Why") // want "call to .+T.+Fatalf from a non-test goroutine"
+			go func() {
+				for j := 0; j < 2; ty.FailNow() { // want "call to .+T.+FailNow from"
+					j++
+					ty.Errorf("Done here")
+				}
+			}()
+		}(i)
+	}
+}
+
+type customType int
+
+func (ct *customType) Fatalf(fmtSpec string, args ...interface{}) {
+	if fmtSpec == "" {
+		panic("empty format specifier")
+	}
+}
+
+func (ct *customType) FailNow() {}
+func (ct *customType) Skip()    {}
+
+func TestWithLogFatalf(t *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func(id int) {
+			go func() {
+				for j := 0; j < 2; j++ {
+					log.Fatal("Done here")
+				}
+			}()
+		}(i)
+	}
+}
+
+func TestWithCustomType(t *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	ct := new(customType)
+	defer ct.FailNow()
+	defer ct.Skip()
+
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func(id int) {
+			go func() {
+				for j := 0; j < 2; j++ {
+					ct.Fatalf("Done here: %d", i)
+				}
+			}()
+		}(i)
+	}
+}