Fixed pkg#102, a message formatting bug.

mrhwick · May 4, 2017 · a77ef41 · a77ef41
1 parent ff09b13
commit a77ef41
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Showing 2 changed files with 40 additions and 32 deletions.
diff --git a/errors.go b/errors.go
@@ -182,8 +182,9 @@ func Wrap(err error, message string) error {
 		return nil
 	}
 	err = &withMessage{
-		cause: err,
-		msg:   message,
+		cause:              err,
+		msg:                message,
+		stackedOnWithStack: true,
 	}
 	return &withStack{
 		err,
@@ -199,8 +200,9 @@ func Wrapf(err error, format string, args ...interface{}) error {
 		return nil
 	}
 	err = &withMessage{
-		cause: err,
-		msg:   fmt.Sprintf(format, args...),
+		cause:              err,
+		msg:                fmt.Sprintf(format, args...),
+		stackedOnWithStack: true,
 	}
 	return &withStack{
 		err,
@@ -215,14 +217,16 @@ func WithMessage(err error, message string) error {
 		return nil
 	}
 	return &withMessage{
-		cause: err,
-		msg:   message,
+		cause:              err,
+		msg:                message,
+		stackedOnWithStack: false,
 	}
 }
 
 type withMessage struct {
-	cause error
-	msg   string
+	cause              error
+	msg                string
+	stackedOnWithStack bool
 }
 
 func (w *withMessage) Error() string { return w.msg + ": " + w.cause.Error() }
@@ -232,8 +236,13 @@ func (w *withMessage) Format(s fmt.State, verb rune) {
 	switch verb {
 	case 'v':
 		if s.Flag('+') {
-			fmt.Fprintf(s, "%+v\n", w.Cause())
-			io.WriteString(s, w.msg)
+			if w.stackedOnWithStack {
+				fmt.Fprintf(s, "%+v\n", w.Cause())
+				io.WriteString(s, w.msg)
+			} else {
+				io.WriteString(s, w.msg+": ")
+				fmt.Fprintf(s, "%+v", w.Cause())
+			}
 			return
 		}
 		fallthrough

diff --git a/format_test.go b/format_test.go
@@ -244,10 +244,9 @@ func TestFormatWithMessage(t *testing.T) {
 		WithMessage(New("error"), "error2"),
 		"%+v",
 		[]string{
-			"error",
+			"error2: error",
 			"github.com/pkg/errors.TestFormatWithMessage\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:244",
-			"error2"},
+				"\t.+/github.com/pkg/errors/format_test.go:244"},
 	}, {
 		WithMessage(io.EOF, "addition1"),
 		"%s",
@@ -259,47 +258,45 @@ func TestFormatWithMessage(t *testing.T) {
 	}, {
 		WithMessage(io.EOF, "addition1"),
 		"%+v",
-		[]string{"EOF", "addition1"},
+		[]string{"addition1: EOF"},
 	}, {
 		WithMessage(WithMessage(io.EOF, "addition1"), "addition2"),
 		"%v",
 		[]string{"addition2: addition1: EOF"},
 	}, {
 		WithMessage(WithMessage(io.EOF, "addition1"), "addition2"),
 		"%+v",
-		[]string{"EOF", "addition1", "addition2"},
+		[]string{"addition2: addition1: EOF"},
 	}, {
 		Wrap(WithMessage(io.EOF, "error1"), "error2"),
 		"%+v",
-		[]string{"EOF", "error1", "error2",
+		[]string{"error1: EOF",
+			"error2",
 			"github.com/pkg/errors.TestFormatWithMessage\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:272"},
+				"\t.+/github.com/pkg/errors/format_test.go:271"},
 	}, {
 		WithMessage(Errorf("error%d", 1), "error2"),
 		"%+v",
-		[]string{"error1",
+		[]string{"error2: error1",
 			"github.com/pkg/errors.TestFormatWithMessage\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:278",
-			"error2"},
+				"\t.+/github.com/pkg/errors/format_test.go:278"},
 	}, {
 		WithMessage(WithStack(io.EOF), "error"),
 		"%+v",
 		[]string{
-			"EOF",
+			"error: EOF",
 			"github.com/pkg/errors.TestFormatWithMessage\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:285",
-			"error"},
+				"\t.+/github.com/pkg/errors/format_test.go:284"},
 	}, {
 		WithMessage(Wrap(WithStack(io.EOF), "inside-error"), "outside-error"),
 		"%+v",
 		[]string{
-			"EOF",
+			"outside-error: EOF",
 			"github.com/pkg/errors.TestFormatWithMessage\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:293",
+				"\t.+/github.com/pkg/errors/format_test.go:291",
 			"inside-error",
 			"github.com/pkg/errors.TestFormatWithMessage\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:293",
-			"outside-error"},
+				"\t.+/github.com/pkg/errors/format_test.go:291"},
 	}}
 
 	for i, tt := range tests {
@@ -315,11 +312,11 @@ func TestFormatGeneric(t *testing.T) {
 		{New("new-error"), []string{
 			"new-error",
 			"github.com/pkg/errors.TestFormatGeneric\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:315"},
+				"\t.+/github.com/pkg/errors/format_test.go:312"},
 		}, {Errorf("errorf-error"), []string{
 			"errorf-error",
 			"github.com/pkg/errors.TestFormatGeneric\n" +
-				"\t.+/github.com/pkg/errors/format_test.go:319"},
+				"\t.+/github.com/pkg/errors/format_test.go:316"},
 		}, {errors.New("errors-new-error"), []string{
 			"errors-new-error"},
 		},
@@ -333,21 +330,21 @@ func TestFormatGeneric(t *testing.T) {
 			func(err error) error { return WithStack(err) },
 			[]string{
 				"github.com/pkg/errors.(func·002|TestFormatGeneric.func2)\n\t" +
-					".+/github.com/pkg/errors/format_test.go:333",
+					".+/github.com/pkg/errors/format_test.go:330",
 			},
 		}, {
 			func(err error) error { return Wrap(err, "wrap-error") },
 			[]string{
 				"wrap-error",
 				"github.com/pkg/errors.(func·003|TestFormatGeneric.func3)\n\t" +
-					".+/github.com/pkg/errors/format_test.go:339",
+					".+/github.com/pkg/errors/format_test.go:336",
 			},
 		}, {
 			func(err error) error { return Wrapf(err, "wrapf-error%d", 1) },
 			[]string{
 				"wrapf-error1",
 				"github.com/pkg/errors.(func·004|TestFormatGeneric.func4)\n\t" +
-					".+/github.com/pkg/errors/format_test.go:346",
+					".+/github.com/pkg/errors/format_test.go:343",
 			},
 		},
 	}
@@ -523,6 +520,8 @@ func testGenericRecursive(t *testing.T, beforeErr error, beforeWant []string, li
 		// Merge two stacks behind each other.
 		if strings.ContainsAny(beforeWant[last], "\n") && strings.ContainsAny(w.want[0], "\n") {
 			want = append(beforeWant[:last], append([]string{beforeWant[last] + "((?s).*)" + w.want[0]}, w.want[1:]...)...)
+		} else if len(w.want) == 1 && !strings.ContainsAny(w.want[0], "\n") {
+			want = append([]string{w.want[0] + ": " + beforeWant[0]}, beforeWant[1:]...)
 		} else {
 			want = append(beforeWant, w.want...)
 		}