Improve API errors message

Include details and optional cause error in the message

fixes #4256

Co-authored-by: Georgi Sabev <[email protected]>

Author: danail-branekov

api/errors/errors.go

@@ -47,11 +47,16 @@ type apiError struct {
 }
 
 func (e apiError) Error() string {
-	if e.cause == nil {
-		return "unknown"
+	detail := e.Detail()
+	if e.cause != nil {
+		return fmt.Sprintf("%s: %s", detail, e.cause.Error())
 	}
 
-	return e.cause.Error()
+	if detail != "" {
+		return detail
+	}
+
+	return "unknown"
 }
 
 func (e apiError) Unwrap() error {

api/errors/errors_test.go

@@ -288,7 +288,7 @@ var _ = Describe("LogAndReturn", func() {
 			Expect(logEntry["level"]).To(Equal("info"))
 			Expect(logEntry["msg"]).To(Equal("some message"))
 			Expect(logEntry["some-key"]).To(Equal("some-value"))
-			Expect(logEntry["reason"]).To(Equal("cause-err"))
+			Expect(logEntry["reason"]).To(ContainSubstring("cause-err"))
 		})
 	})
 
@@ -301,7 +301,7 @@ var _ = Describe("LogAndReturn", func() {
 			Expect(logEntry["level"]).To(Equal("info"))
 			Expect(logEntry["msg"]).To(Equal("some message"))
 			Expect(logEntry["some-key"]).To(Equal("some-value"))
-			Expect(logEntry["reason"]).To(Equal("wrapping: cause-err"))
+			Expect(logEntry["reason"]).To(MatchRegexp("wrapping:.*cause-err"))
 		})
 	})
 })
@@ -355,14 +355,35 @@ var _ = Describe("invalid lists", func() {
 	})
 })
 
-type testApiError struct {
-	apierrors.ApiError
-}
+var _ = Describe("Error", func() {
+	var (
+		err         apierrors.ApiError
+		errorString string
+	)
 
-func (e testApiError) Error() string {
-	return ""
-}
+	BeforeEach(func() {
+		err = apierrors.NewUnknownError(errors.New("oops"))
+	})
+
+	JustBeforeEach(func() {
+		errorString = err.Error()
+	})
 
-func (e testApiError) Unwrap() error {
-	return nil
+	It("returns error details and cause", func() {
+		Expect(errorString).To(Equal("An unknown error occurred.: oops"))
+	})
+
+	When("the error has no cause", func() {
+		BeforeEach(func() {
+			err = apierrors.NewUnknownError(nil)
+		})
+
+		It("returns details only", func() {
+			Expect(errorString).To(Equal("An unknown error occurred."))
+		})
+	})
+})
+
+type testApiError struct {
+	apierrors.ApiError
 }