Replace errors.Is with IsNotFoundError utility function across handlers and tests for improved readability and consistency. Remove redundant errors imports.

internal/capability/handler.go

@@ -3,7 +3,6 @@ package capability
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"log/slog"
 	"net/http"
 	"products/internal"
@@ -51,7 +50,7 @@ func (h *handler) GetCapability(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	capability, err := h.service.GetCapability(ctxWithTimeout, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Capability not found"}, http.StatusNotFound)
 			return
 		}
@@ -72,7 +71,7 @@ func (h *handler) GetCapabilitiesByFlow(w http.ResponseWriter, r *http.Request)
 	defer cancel()
 	capabilities, err := h.service.GetCapabilitiesByFlow(ctxWithTimeout, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Flow not found"}, http.StatusNotFound)
 			return
 		}
@@ -93,7 +92,7 @@ func (h *handler) GetCapabilitiesByProduct(w http.ResponseWriter, r *http.Reques
 	defer cancel()
 	capabilities, err := h.service.GetCapabilitiesByProduct(ctxWithTimeout, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Product not found"}, http.StatusNotFound)
 			return
 		}
@@ -124,7 +123,7 @@ func (h *handler) UpdateCapability(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	capability, err := h.service.UpdateCapability(ctxWithTimeout, *req)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Capability not found"}, http.StatusNotFound)
 			return
 		}
@@ -145,7 +144,7 @@ func (h *handler) DeleteCapability(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	err := h.service.DeleteCapability(ctxWithTimout, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Capability not found"}, http.StatusNotFound)
 			return
 		}
@@ -171,10 +170,10 @@ func (h *handler) CreateCapabilityStep(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	capStep, err := h.service.CreateCapabilityStep(ctxWithTimeout, *req)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error()}, http.StatusNotFound)
 			return
-		} else if errors.Is(err, internal.ValidationError{}) {
+		} else if internal.IsValidationError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error()}, http.StatusBadRequest)
 			return
 		}
@@ -195,7 +194,7 @@ func (h *handler) DeleteCapabilityStep(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	err := h.service.DeleteCapabilityStep(ctxWithTimeout, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Capability step not found", Instance: strconv.Itoa(id)}, http.StatusNotFound)
 			return
 		}
@@ -216,7 +215,7 @@ func (h *handler) GetCapabilitySteps(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	steps, err := h.service.GetCapabilitySteps(ctxWithTimeout, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Capability not found"}, http.StatusNotFound)
 			return
 		}

internal/capability/service_capability_test.go

@@ -151,7 +151,7 @@ func TestService_CreateCapability(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},
@@ -169,7 +169,7 @@ func TestService_CreateCapability(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},
@@ -269,7 +269,7 @@ func TestService_GetCapability(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},
@@ -366,7 +366,7 @@ func TestService_GetCapabilitiesByProduct(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},
@@ -476,7 +476,7 @@ func TestService_GetCapabilitiesByFlow(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},
@@ -579,7 +579,7 @@ func TestService_UpdateCapability(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},
@@ -675,7 +675,7 @@ func TestService_DeleteCapability(t *testing.T) {
 				}
 			},
 			checkError: func(t *testing.T, err error) {
-				if !errors.Is(err, internal.NotFoundError{}) {
+				if !internal.IsNotFoundError(err) {
 					t.Errorf("expected NotFoundError, got %T", err)
 				}
 			},

internal/errors.go

@@ -1,6 +1,7 @@
 package internal
 
 import (
+	"errors"
 	"strconv"
 )
 
@@ -13,11 +14,6 @@ func (e NotFoundError) Error() string {
 	return e.itemType + " not found with ID: " + strconv.Itoa(e.id)
 }
 
-func (e NotFoundError) Is(target error) bool {
-	_, ok := target.(NotFoundError)
-	return ok
-}
-
 type ValidationError struct {
 	msg string
 }
@@ -26,11 +22,6 @@ func (e ValidationError) Error() string {
 	return e.msg
 }
 
-func (e ValidationError) Is(target error) bool {
-	_, ok := target.(ValidationError)
-	return ok
-}
-
 func NewValidationErr(message string) ValidationError {
 	return ValidationError{
 		msg: message,
@@ -40,3 +31,13 @@ func NewValidationErr(message string) ValidationError {
 func NewNotFoundError(id int, itemType string) NotFoundError {
 	return NotFoundError{id: id, itemType: itemType}
 }
+
+func IsNotFoundError(err error) bool {
+	_, ok := errors.AsType[NotFoundError](err)
+	return ok
+}
+
+func IsValidationError(err error) bool {
+	_, ok := errors.AsType[ValidationError](err)
+	return ok
+}

internal/errors_test.go

@@ -0,0 +1,77 @@
+package internal
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+)
+
+func TestIsNotFoundError(t *testing.T) {
+	t.Run("returns true for NotFoundError", func(t *testing.T) {
+		err := NewNotFoundError(1, "Product")
+		if !IsNotFoundError(err) {
+			t.Errorf("IsNotFoundError(err) = false; want true")
+		}
+	})
+
+	t.Run("returns true for wrapped NotFoundError", func(t *testing.T) {
+		err := fmt.Errorf("wrapped: %w", NewNotFoundError(1, "Product"))
+		if !IsNotFoundError(err) {
+			t.Errorf("IsNotFoundError(err) = false; want true")
+		}
+	})
+
+	t.Run("returns false for other errors", func(t *testing.T) {
+		err := errors.New("some other error")
+		if IsNotFoundError(err) {
+			t.Errorf("IsNotFoundError(err) = true; want false")
+		}
+	})
+
+	t.Run("returns false for nil error", func(t *testing.T) {
+		if IsNotFoundError(nil) {
+			t.Errorf("IsNotFoundError(nil) = true; want false")
+		}
+	})
+}
+
+func TestIsValidationError(t *testing.T) {
+	t.Run("returns true for ValidationError", func(t *testing.T) {
+		err := NewValidationErr("invalid input")
+		if !IsValidationError(err) {
+			t.Errorf("IsValidationError(err) = false; want true")
+		}
+	})
+
+	t.Run("returns true for wrapped ValidationError", func(t *testing.T) {
+		err := fmt.Errorf("wrapped: %w", NewValidationErr("invalid input"))
+		if !IsValidationError(err) {
+			t.Errorf("IsValidationError(err) = false; want true")
+		}
+	})
+
+	t.Run("returns false for other errors", func(t *testing.T) {
+		err := errors.New("some other error")
+		if IsValidationError(err) {
+			t.Errorf("IsValidationError(err) = true; want false")
+		}
+	})
+
+	t.Run("returns false for nil error", func(t *testing.T) {
+		if IsValidationError(nil) {
+			t.Errorf("IsValidationError(nil) = true; want false")
+		}
+	})
+}
+
+func TestNotFoundError(t *testing.T) {
+	err := NewNotFoundError(123, "Product")
+
+	t.Run("Error message", func(t *testing.T) {
+		expected := "Product not found with ID: 123"
+		if err.Error() != expected {
+			t.Errorf("expected %q, got %q", expected, err.Error())
+		}
+	})
+
+}

internal/flow/handler.go

@@ -41,7 +41,7 @@ func (h *handler) CreateFlow(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	flow, err := h.flowService.CreateFlow(contextWithTimeOut, *req, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error()}, http.StatusNotFound)
 			return
 		}
@@ -61,7 +61,7 @@ func (h *handler) GetFlowById(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	flow, err := h.flowService.GetFlowById(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -81,7 +81,7 @@ func (h *handler) GetFlowsByProduct(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	flows, err := h.flowService.GetFlowsByProduct(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -114,7 +114,7 @@ func (h *handler) UpdateFlow(w http.ResponseWriter, r *http.Request) {
 
 	flow, err := h.flowService.UpdateFlow(contextWithTimeOut, *req, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -137,7 +137,7 @@ func (h *handler) DeleteFlow(w http.ResponseWriter, r *http.Request) {
 
 	err := h.flowService.DeleteFlow(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -179,7 +179,7 @@ func (h *handler) CreateFlowStep(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	flowStep, err := h.flowService.CreateFlowStep(contextWithTimeOut, *req)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -214,7 +214,7 @@ func (h *handler) DeleteFlowStep(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	err := h.flowService.DeleteFlowStep(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -238,7 +238,7 @@ func (h *handler) GetFlowSteps(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	flowSteps, err := h.flowService.GetFlowSteps(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}
@@ -258,7 +258,7 @@ func (h *handler) GetFlowPath(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	flowPath, err := h.flowService.GetFlowPath(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: err.Error(), Instance: r.URL.Path}, http.StatusNotFound)
 			return
 		}

internal/platform/handler.go

@@ -3,7 +3,6 @@ package platform
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"net/http"
 	"products/internal"
 	"products/internal/platform/db"
@@ -67,7 +66,7 @@ func (h *handler) UpdatePlatform(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	_, err := h.service.UpdatePlatform(contextWithTimeOut, req, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Platform not found"}, http.StatusNotFound)
 			return
 		}
@@ -88,12 +87,11 @@ func (h *handler) DeletePlatform(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	_, err := h.service.DeletePlatform(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Platform not found"}, http.StatusNotFound)
 			return
 		}
-		logger := internal.LoggerFromContext(r.Context())
-		logger.Error("Failed to delete platform", "error", err, "platform_id", id)
+		internal.LoggerFromContext(r.Context()).Error("Failed to delete platform", "error", err, "platform_id", id)
 		internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Internal server error"}, http.StatusInternalServerError)
 		return
 	}
@@ -125,7 +123,7 @@ func (h *handler) GetPlatform(w http.ResponseWriter, r *http.Request) {
 	defer cancel()
 	platform, err := h.service.GetPlatform(contextWithTimeOut, id)
 	if err != nil {
-		if errors.Is(err, internal.NotFoundError{}) {
+		if internal.IsNotFoundError(err) {
 			internal.HandleHttpError(w, internal.ErrorEnvelope{Detail: "Platform not found"}, http.StatusNotFound)
 			return
 		}