make the logging of stacks in errors an opt-in behavior

go/vt/vterrors/errors_test.go

@@ -172,15 +172,16 @@ func TestStackFormat(t *testing.T) {
  err := outer()
  got := fmt.Sprintf("%v", err)
 
- assertStringContains(t, got, "innerMost")
- assertStringContains(t, got, "middle")
- assertStringContains(t, got, "outer")
-}
+ assertContains(t, got, "innerMost", false)
+ assertContains(t, got, "middle", false)
+ assertContains(t, got, "outer", false)
 
-func assertStringContains(t *testing.T, s, substring string) {
- if !strings.Contains(s, substring) {
- t.Errorf("string did not contain `%v`: \n %v", substring, s)
- }
+ LogErrStacks = true
+ defer func() { LogErrStacks = false }()
+ got = fmt.Sprintf("%v", err)
+ assertContains(t, got, "innerMost", true)
+ assertContains(t, got, "middle", true)
+ assertContains(t, got, "outer", true)
 }
 
 // errors.New, etc values are not expected to be compared by value
@@ -256,23 +257,34 @@ func TestWrapping(t *testing.T) {
  err1 := Errorf(vtrpcpb.Code_UNAVAILABLE, "foo")
  err2 := Wrapf(err1, "bar")
  err3 := Wrapf(err2, "baz")
+ errorWithoutStack := fmt.Sprintf("%v", err3)
+
+ LogErrStacks = true
  errorWithStack := fmt.Sprintf("%v", err3)
+ LogErrStacks = false
 
  assertEquals(t, err3.Error(), "baz: bar: foo")
- assertContains(t, errorWithStack, "foo")
- assertContains(t, errorWithStack, "bar")
- assertContains(t, errorWithStack, "baz")
- assertContains(t, errorWithStack, "TestWrapping")
+ assertContains(t, errorWithoutStack, "foo", true)
+ assertContains(t, errorWithoutStack, "bar", true)
+ assertContains(t, errorWithoutStack, "baz", true)
+ assertContains(t, errorWithoutStack, "TestWrapping", false)
+
+ assertContains(t, errorWithStack, "foo", true)
+ assertContains(t, errorWithStack, "bar", true)
+ assertContains(t, errorWithStack, "baz", true)
+ assertContains(t, errorWithStack, "TestWrapping", true)
+
 }
 
-func assertContains(t *testing.T, s, substring string) {
- if !strings.Contains(s, substring) {
- t.Fatalf("expected string that contains [%s] but got [%s]", substring, s)
+func assertContains(t *testing.T, s, substring string, contains bool) {
+ t.Helper()
+ if doesContain := strings.Contains(s, substring); doesContain != contains {
+ t.Errorf("string `%v` contains `%v`: %v, want %v", s, substring, doesContain, contains)
  }
 }
 
 func assertEquals(t *testing.T, a, b interface{}) {
  if a != b {
  t.Fatalf("expected [%s] to be equal to [%s]", a, b)
  }
-}
+}

go/vt/vterrors/vterrors.go

@@ -70,13 +70,22 @@
 package vterrors
 
 import (
+ "flag"
  "fmt"
  "io"
 
  "golang.org/x/net/context"
  vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
 )
 
+// LogErrStacks controls whether or not printing errors includes the
+// embedded stack trace in the output.
+var LogErrStacks bool
+
+func init() {
+ flag.BoolVar(&LogErrStacks, "LogErrStacks", false, "log stack traces in errors")
+}
+
 // New returns an error with the supplied message.
 // New also records the stack trace at the point it was called.
 func New(code vtrpcpb.Code, message string) error {
@@ -122,7 +131,9 @@ func (f *fundamental) Format(s fmt.State, verb rune) {
  case 'v':
  panicIfError(io.WriteString(s, "Code: "+f.code.String()+"\n"))
  panicIfError(io.WriteString(s, f.msg+"\n"))
- f.stack.Format(s, verb)
+ if LogErrStacks {
+ f.stack.Format(s, verb)
+ }
  return
  case 's':
  panicIfError(io.WriteString(s, f.msg))
@@ -198,7 +209,9 @@ func (w *wrapping) Format(s fmt.State, verb rune) {
  if rune('v') == verb {
  panicIfError(fmt.Fprintf(s, "%v\n", w.Cause()))
  panicIfError(io.WriteString(s, w.msg))
- w.stack.Format(s, verb)
+ if LogErrStacks {
+ w.stack.Format(s, verb)
+ }
  return
  }