Merge pull request #15 from m-mizutani/fix/printable-msg

fix: cause of printable

errors.go

@@ -94,40 +94,40 @@ func (x *Error) copy(dst *Error) {
 }
 
 // Printable returns printable object
-func (x *Error) Printable() *printable {
-	e := &printable{
+func (x *Error) Printable() *Printable {
+	e := &Printable{
 		Message:    x.msg,
 		ID:         x.id,
 		StackTrace: x.Stacks(),
-		Cause:      x.cause,
 		Values:     make(map[string]any),
 	}
 	for k, v := range x.values {
 		e.Values[k] = v
 	}
+
+	if cause := Unwrap(x.cause); cause != nil {
+		e.Cause = cause.Printable()
+	} else if x.cause != nil {
+		e.Cause = x.cause.Error()
+	}
 	return e
 }
 
-type printable struct {
+type Printable struct {
 	Message    string         `json:"message"`
 	ID         string         `json:"id"`
 	StackTrace []*Stack       `json:"stacktrace"`
-	Cause      error          `json:"cause"`
+	Cause      any            `json:"cause"`
 	Values     map[string]any `json:"values"`
 }
 
 // Error returns error message for error interface
 func (x *Error) Error() string {
-	s := x.msg
-	cause := x.cause
-
-	if cause == nil {
-		return s
+	if x.cause == nil {
+		return x.msg
 	}
 
-	s = fmt.Sprintf("%s: %v", s, cause.Error())
-
-	return s
+	return fmt.Sprintf("%s: %v", x.msg, x.cause.Error())
 }
 
 // Format returns:

errors_test.go

@@ -107,7 +107,7 @@ func TestErrorCode(t *testing.T) {
 	}
 }
 
-func TestPrintable(t *testing.T) {
+func TestPrintableWithGoErr(t *testing.T) {
 	cause := errors.New("test")
 	err := goerr.Wrap(cause, "oops").ID("E001").With("blue", "five")
 
@@ -118,8 +118,31 @@ func TestPrintable(t *testing.T) {
 	if p.ID != "E001" {
 		t.Errorf("Expected ID to be 'E001', got '%s'", p.ID)
 	}
-	if p.Cause != cause {
-		t.Errorf("Expected cause to be '%v', got '%v'", cause, p.Cause)
+	if s, ok := p.Cause.(string); !ok {
+		t.Errorf("Expected cause is string, got '%t'", p.Cause)
+	} else if s != "test" {
+		t.Errorf("Expected message is 'test', got '%s'", s)
+	}
+	if p.Values["blue"] != "five" {
+		t.Errorf("Expected value for 'blue' to be 'five', got '%v'", p.Values["blue"])
+	}
+}
+
+func TestPrintableWithError(t *testing.T) {
+	cause := goerr.New("test")
+	err := goerr.Wrap(cause, "oops").ID("E001").With("blue", "five")
+
+	p := err.Printable()
+	if p.Message != "oops" {
+		t.Errorf("Expected message to be 'oops', got '%s'", p.Message)
+	}
+	if p.ID != "E001" {
+		t.Errorf("Expected ID to be 'E001', got '%s'", p.ID)
+	}
+	if cp, ok := p.Cause.(*goerr.Printable); !ok {
+		t.Errorf("Expected cause is goerr.Printable, got '%t'", p.Cause)
+	} else if cp.Message != "test" {
+		t.Errorf("Expected message is 'test', got '%s'", cp.Message)
 	}
 	if p.Values["blue"] != "five" {
 		t.Errorf("Expected value for 'blue' to be 'five', got '%v'", p.Values["blue"])