tests: add more testing to the errors package

server/rosetta/lib/errors/errors.go

@@ -38,17 +38,13 @@ func (e *Error) Error() string {
 // Is implements errors.Is for *Error, two errors are considered equal
 // if their error codes are identical
 func (e *Error) Is(err error) bool {
-	// check if one is nil and the other isn't
-	if (e == nil && err != nil) || (err == nil && e != nil) {
-		return false
-	}
 	// assert it can be casted
 	rosErr, ok := err.(*Error)
-	if !ok {
+	if rosErr == nil || !ok {
 		return false
 	}
 	// check that both *Error's are correctly initialized to avoid dereference panics
-	if (rosErr.rosErr == nil && e.rosErr != nil) || (e.rosErr == nil && rosErr.rosErr != nil) {
+	if rosErr.rosErr == nil || e.rosErr == nil {
 		return false
 	}
 	// messages are equal if their error codes match
@@ -71,12 +67,10 @@ func WrapError(err *Error, msg string) *Error {
 // ToRosetta attempts to converting an error into a rosetta
 // error, if the error cannot be converted it will be parsed as unknown
 func ToRosetta(err error) *types.Error {
-	if err == nil {
-		return nil
-	}
+	// if it's null or not known
 	rosErr, ok := err.(*Error)
-	if !ok {
-		return ToRosetta(WrapError(ErrUnknown, err.Error()))
+	if rosErr == nil || !ok {
+		return ToRosetta(WrapError(ErrUnknown, ErrUnknown.Error()))
 	}
 	return rosErr.rosErr
 }

server/rosetta/lib/errors/errors_test.go

@@ -31,3 +31,38 @@ func TestRegisterError(t *testing.T) {
 	assert.NotNil(t, error)
 
 }
+
+func TestError_Error(t *testing.T) {
+	var error *Error
+	// nil cases
+	assert.False(t, ErrOffline.Is(error))
+	error = &Error{}
+	assert.False(t, ErrOffline.Is(error))
+	// wrong type
+	assert.False(t, ErrOffline.Is(&MyError{}))
+	// test with wrapping an error
+	error = WrapError(ErrOffline, "offline")
+	assert.True(t, ErrOffline.Is(error))
+
+	// test equality
+	assert.False(t, ErrOffline.Is(ErrBadGateway))
+	assert.True(t, ErrBadGateway.Is(ErrBadGateway))
+}
+
+func TestToRosetta(t *testing.T) {
+	var error *Error
+	// nil case
+	assert.NotNil(t, ToRosetta(error))
+	// wrong type
+	assert.NotNil(t, ToRosetta(&MyError{}))
+}
+
+type MyError struct {
+}
+
+func (e *MyError) Error() string {
+	return ""
+}
+func (e *MyError) Is(err error) bool {
+	return true
+}