New Error (#180)

* New Error can capture Stacktrace
* Intelligent ErrorWrap
* Review fixes

common/errors_test.go

@@ -0,0 +1,107 @@
+package common
+
+import (
+	fmt "fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestErrorPanic(t *testing.T) {
+	type pnk struct {
+		msg string
+	}
+
+	capturePanic := func() (err Error) {
+		defer func() {
+			if r := recover(); r != nil {
+				err = ErrorWrap(r, "This is the message in ErrorWrap(r, message).")
+			}
+			return
+		}()
+		panic(pnk{"something"})
+		return nil
+	}
+
+	var err = capturePanic()
+
+	assert.Equal(t, pnk{"something"}, err.Cause())
+	assert.Equal(t, pnk{"something"}, err.T())
+	assert.Equal(t, "This is the message in ErrorWrap(r, message).", err.Message())
+	assert.Equal(t, "Error{`This is the message in ErrorWrap(r, message).`}", fmt.Sprintf("%v", err))
+	assert.Contains(t, fmt.Sprintf("%#v", err), "Message: This is the message in ErrorWrap(r, message).")
+	assert.Contains(t, fmt.Sprintf("%#v", err), "Stack Trace:\n    0")
+}
+
+func TestErrorWrapSomething(t *testing.T) {
+
+	var err = ErrorWrap("something", "formatter%v%v", 0, 1)
+
+	assert.Equal(t, "something", err.Cause())
+	assert.Equal(t, "something", err.T())
+	assert.Equal(t, "formatter01", err.Message())
+	assert.Equal(t, "Error{`formatter01`}", fmt.Sprintf("%v", err))
+	assert.Regexp(t, `Message: formatter01\n`, fmt.Sprintf("%#v", err))
+	assert.Contains(t, fmt.Sprintf("%#v", err), "Stack Trace:\n    0")
+}
+
+func TestErrorWrapNothing(t *testing.T) {
+
+	var err = ErrorWrap(nil, "formatter%v%v", 0, 1)
+
+	assert.Equal(t, nil, err.Cause())
+	assert.Equal(t, nil, err.T())
+	assert.Equal(t, "formatter01", err.Message())
+	assert.Equal(t, "Error{`formatter01`}", fmt.Sprintf("%v", err))
+	assert.Regexp(t, `Message: formatter01\n`, fmt.Sprintf("%#v", err))
+	assert.Contains(t, fmt.Sprintf("%#v", err), "Stack Trace:\n    0")
+}
+
+func TestErrorNewError(t *testing.T) {
+
+	var err = NewError("formatter%v%v", 0, 1)
+
+	assert.Equal(t, nil, err.Cause())
+	assert.Equal(t, "formatter%v%v", err.T())
+	assert.Equal(t, "formatter01", err.Message())
+	assert.Equal(t, "Error{`formatter01`}", fmt.Sprintf("%v", err))
+	assert.Regexp(t, `Message: formatter01\n`, fmt.Sprintf("%#v", err))
+	assert.NotContains(t, fmt.Sprintf("%#v", err), "Stack Trace")
+}
+
+func TestErrorNewErrorWithStacktrace(t *testing.T) {
+
+	var err = NewError("formatter%v%v", 0, 1).Stacktrace()
+
+	assert.Equal(t, nil, err.Cause())
+	assert.Equal(t, "formatter%v%v", err.T())
+	assert.Equal(t, "formatter01", err.Message())
+	assert.Equal(t, "Error{`formatter01`}", fmt.Sprintf("%v", err))
+	assert.Regexp(t, `Message: formatter01\n`, fmt.Sprintf("%#v", err))
+	assert.Contains(t, fmt.Sprintf("%#v", err), "Stack Trace:\n    0")
+}
+
+func TestErrorNewErrorWithTrace(t *testing.T) {
+
+	var err = NewError("formatter%v%v", 0, 1)
+	err.Trace("trace %v", 1)
+	err.Trace("trace %v", 2)
+	err.Trace("trace %v", 3)
+
+	assert.Equal(t, nil, err.Cause())
+	assert.Equal(t, "formatter%v%v", err.T())
+	assert.Equal(t, "formatter01", err.Message())
+	assert.Equal(t, "Error{`formatter01`}", fmt.Sprintf("%v", err))
+	assert.Regexp(t, `Message: formatter01\n`, fmt.Sprintf("%#v", err))
+	dump := fmt.Sprintf("%#v", err)
+	assert.NotContains(t, dump, "Stack Trace")
+	assert.Regexp(t, `common/errors_test\.go:[0-9]+ - trace 1`, dump)
+	assert.Regexp(t, `common/errors_test\.go:[0-9]+ - trace 2`, dump)
+	assert.Regexp(t, `common/errors_test\.go:[0-9]+ - trace 3`, dump)
+}
+
+func TestErrorWrapError(t *testing.T) {
+	var err1 error = NewError("my message")
+	var err2 error = ErrorWrap(err1, "another message")
+	assert.Equal(t, err1, err2)
+}