WithCause

Author: marrow16

error.go

@@ -69,11 +69,8 @@ func (e *err) Cause() error {
 }
 
 func (e *err) WithCause(cause error) StackError {
-	return &err{
-		message: e.message,
-		stack:   e.stack,
-		cause:   cause,
-	}
+	e.cause = cause
+	return e
 }
 
 func (e *err) StackInfo() StackInfo {

error_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/stretchr/testify/require"
+	"runtime"
 	"strings"
 	"testing"
 )
@@ -25,6 +26,7 @@ func TestWrap(t *testing.T) {
 	defer func() {
 		DefaultPackageName = ""
 	}()
+	ln := lineNumber() + 1
 	e := Wrap(errors.New("cause"), "fooey")
 	require.Error(t, e)
 	require.Equal(t, "fooey", e.Error())
@@ -34,7 +36,7 @@ func TestWrap(t *testing.T) {
 
 	si := e.StackInfo()
 	require.Len(t, si, 1)
-	require.Equal(t, 28, si[0].Line)
+	require.Equal(t, ln, si[0].Line)
 
 	require.NoError(t, Wrap(nil, "fooey"))
 }
@@ -67,39 +69,42 @@ func TestError_StackInfo(t *testing.T) {
 		defer func() {
 			DefaultPackageName = ""
 		}()
+		ln := lineNumber() + 1
 		e := New("fooey")
 		require.Error(t, e)
 		si := e.StackInfo()
 		require.Len(t, si, 1)
 		require.True(t, strings.HasPrefix(si[0].Function, "github.com/go-andiamo/stackerr"))
 		require.Contains(t, si[0].Function, "TestError_StackInfo")
-		require.Equal(t, 70, si[0].Line)
+		require.Equal(t, ln, si[0].Line)
 	})
 	t.Run("with DefaultPackageFilter", func(t *testing.T) {
 		DefaultPackageFilter = &testPackageFilter{}
 		defer func() {
 			DefaultPackageFilter = nil
 		}()
+		ln := lineNumber() + 1
 		e := New("fooey")
 		require.Error(t, e)
 		si := e.StackInfo()
 		require.Len(t, si, 1)
 		require.True(t, strings.HasPrefix(si[0].Function, "github.com/go-andiamo/stackerr"))
 		require.Contains(t, si[0].Function, "TestError_StackInfo")
-		require.Equal(t, 83, si[0].Line)
+		require.Equal(t, ln, si[0].Line)
 	})
 	t.Run("with SetDefaultPackageFilter", func(t *testing.T) {
 		SetDefaultPackageFilter("github.com/go-andiamo/stackerr")
 		defer func() {
 			DefaultPackageFilter = nil
 		}()
+		ln := lineNumber() + 1
 		e := New("fooey")
 		require.Error(t, e)
 		si := e.StackInfo()
 		require.Len(t, si, 1)
 		require.True(t, strings.HasPrefix(si[0].Function, "github.com/go-andiamo/stackerr"))
 		require.Contains(t, si[0].Function, "TestError_StackInfo")
-		require.Equal(t, 96, si[0].Line)
+		require.Equal(t, ln, si[0].Line)
 	})
 }
 
@@ -127,6 +132,7 @@ func TestError_Format(t *testing.T) {
 		defer func() {
 			DefaultPackageName = ""
 		}()
+		ln := lineNumber() + 1
 		e := New("fooey")
 		require.Error(t, e)
 		out := fmt.Sprintf("%+v", e)
@@ -136,13 +142,14 @@ func TestError_Format(t *testing.T) {
 		require.Equal(t, "Stack:", lines[1])
 		require.True(t, strings.HasPrefix(lines[2], "\tgithub.com/go-andiamo/stackerr."))
 		require.Contains(t, lines[2], ".TestError_Format.")
-		require.True(t, strings.HasSuffix(lines[2], ":130"))
+		require.True(t, strings.HasSuffix(lines[2], fmt.Sprintf(":%d", ln)))
 	})
 	t.Run("+v with cause", func(t *testing.T) {
 		DefaultPackageName = "stackerr"
 		defer func() {
 			DefaultPackageName = ""
 		}()
+		ln := lineNumber() + 1
 		e := New("fooey").WithCause(errors.New("cause"))
 		require.Error(t, e)
 		out := fmt.Sprintf("%+v", e)
@@ -152,7 +159,7 @@ func TestError_Format(t *testing.T) {
 		require.Equal(t, "Stack:", lines[1])
 		require.True(t, strings.HasPrefix(lines[2], "\tgithub.com/go-andiamo/stackerr."))
 		require.Contains(t, lines[2], ".TestError_Format.")
-		require.True(t, strings.HasSuffix(lines[2], ":146"))
+		require.True(t, strings.HasSuffix(lines[2], fmt.Sprintf(":%d", ln)))
 	})
 	t.Run("s", func(t *testing.T) {
 		e := New("fooey")
@@ -180,3 +187,11 @@ func TestPackageFromFunction(t *testing.T) {
 	require.Equal(t, "stackerr", full)
 	require.Equal(t, "stackerr", short)
 }
+
+func lineNumber() int {
+	const skip = 2
+	pc := make([]uintptr, 1)
+	n := runtime.Callers(skip, pc)
+	frame, _ := runtime.CallersFrames(pc[:n]).Next()
+	return frame.Line
+}