fix(plugins): enhance error handling in checkErr function

Improved the error handling logic in the checkErr function to map specific error strings to their corresponding API error constants. This change ensures that errors from plugins are correctly identified and returned, enhancing the robustness of error reporting.

Signed-off-by: Deluan <deluan@navidrome.org>

plugins/base_capability_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 
+	"github.com/navidrome/navidrome/plugins/api"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -34,7 +35,16 @@ var _ = Describe("baseCapability", func() {
 
 var _ = Describe("checkErr", func() {
 	Context("when resp is nil", func() {
-		It("should return the original error unchanged", func() {
+		It("should return nil error when both resp and err are nil", func() {
+			var resp *testErrorResponse
+
+			result, err := checkErr(resp, nil)
+
+			Expect(result).To(BeNil())
+			Expect(err).To(BeNil())
+		})
+
+		It("should return original error unchanged for non-API errors", func() {
 			var resp *testErrorResponse
 			originalErr := errors.New("original error")
 
@@ -44,13 +54,24 @@ var _ = Describe("checkErr", func() {
 			Expect(err).To(Equal(originalErr))
 		})
 
-		It("should return nil error when both resp and err are nil", func() {
+		It("should return mapped API error for ErrNotImplemented", func() {
 			var resp *testErrorResponse
+			err := errors.New("plugin:not_implemented")
 
-			result, err := checkErr(resp, nil)
+			result, mappedErr := checkErr(resp, err)
 
 			Expect(result).To(BeNil())
-			Expect(err).To(BeNil())
+			Expect(mappedErr).To(Equal(api.ErrNotImplemented))
+		})
+
+		It("should return mapped API error for ErrNotFound", func() {
+			var resp *testErrorResponse
+			err := errors.New("plugin:not_found")
+
+			result, mappedErr := checkErr(resp, err)
+
+			Expect(result).To(BeNil())
+			Expect(mappedErr).To(Equal(api.ErrNotFound))
 		})
 	})
 
@@ -94,7 +115,49 @@ var _ = Describe("checkErr", func() {
 			result, err := checkErr(resp, originalErr)
 
 			Expect(result).To(Equal(resp))
-			Expect(err).To(MatchError("plugin error: original error"))
+			Expect(err).To(HaveOccurred())
+			// Check that both error messages are present in the joined error
+			errStr := err.Error()
+			Expect(errStr).To(ContainSubstring("plugin error"))
+			Expect(errStr).To(ContainSubstring("original error"))
+		})
+
+		It("should return mapped API error for ErrNotImplemented when no original error", func() {
+			resp := &testErrorResponse{errorMsg: "plugin:not_implemented"}
+
+			result, err := checkErr(resp, nil)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotImplemented))
+		})
+
+		It("should return mapped API error for ErrNotFound when no original error", func() {
+			resp := &testErrorResponse{errorMsg: "plugin:not_found"}
+
+			result, err := checkErr(resp, nil)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotFound))
+		})
+
+		It("should return mapped API error for ErrNotImplemented even with original error", func() {
+			resp := &testErrorResponse{errorMsg: "plugin:not_implemented"}
+			originalErr := errors.New("original error")
+
+			result, err := checkErr(resp, originalErr)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotImplemented))
+		})
+
+		It("should return mapped API error for ErrNotFound even with original error", func() {
+			resp := &testErrorResponse{errorMsg: "plugin:not_found"}
+			originalErr := errors.New("original error")
+
+			result, err := checkErr(resp, originalErr)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotFound))
 		})
 	})
 
@@ -106,7 +169,7 @@ var _ = Describe("checkErr", func() {
 			result, err := checkErr(resp, originalErr)
 
 			Expect(result).To(Equal(resp))
-			Expect(err).To(Equal(originalErr))
+			Expect(err).To(MatchError(originalErr))
 		})
 
 		It("should return nil error when both are empty/nil", func() {
@@ -117,6 +180,16 @@ var _ = Describe("checkErr", func() {
 			Expect(result).To(Equal(resp))
 			Expect(err).To(BeNil())
 		})
+
+		It("should map original API error when response error is empty", func() {
+			resp := &testErrorResponse{errorMsg: ""}
+			originalErr := errors.New("plugin:not_implemented")
+
+			result, err := checkErr(resp, originalErr)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotImplemented))
+		})
 	})
 
 	Context("when resp does not implement errorResponse", func() {
@@ -138,6 +211,16 @@ var _ = Describe("checkErr", func() {
 			Expect(result).To(Equal(resp))
 			Expect(err).To(BeNil())
 		})
+
+		It("should map original API error when response doesn't implement errorResponse", func() {
+			resp := &testNonErrorResponse{data: "some data"}
+			originalErr := errors.New("plugin:not_found")
+
+			result, err := checkErr(resp, originalErr)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotFound))
+		})
 	})
 
 	Context("when resp is a value type (not pointer)", func() {
@@ -148,7 +231,11 @@ var _ = Describe("checkErr", func() {
 			result, err := checkErr(resp, originalErr)
 
 			Expect(result).To(Equal(resp))
-			Expect(err).To(MatchError("value error: original error"))
+			Expect(err).To(HaveOccurred())
+			// Check that both error messages are present in the joined error
+			errStr := err.Error()
+			Expect(errStr).To(ContainSubstring("value error"))
+			Expect(errStr).To(ContainSubstring("original error"))
 		})
 
 		It("should handle value types with empty error", func() {
@@ -158,7 +245,17 @@ var _ = Describe("checkErr", func() {
 			result, err := checkErr(resp, originalErr)
 
 			Expect(result).To(Equal(resp))
-			Expect(err).To(Equal(originalErr))
+			Expect(err).To(MatchError(originalErr))
+		})
+
+		It("should handle value types with API error", func() {
+			resp := testValueErrorResponse{errorMsg: "plugin:not_implemented"}
+			originalErr := errors.New("original error")
+
+			result, err := checkErr(resp, originalErr)
+
+			Expect(result).To(Equal(resp))
+			Expect(err).To(MatchError(api.ErrNotImplemented))
 		})
 	})
 })