feat(context): add GetError and GetErrorSlice methods for error retrieval (#4502)

Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>

context.go

@@ -386,6 +386,11 @@ func (c *Context) GetDuration(key any) time.Duration {
 	return getTyped[time.Duration](c, key)
 }
 
+// GetError returns the value associated with the key as an error.
+func (c *Context) GetError(key any) error {
+	return getTyped[error](c, key)
+}
+
 // GetIntSlice returns the value associated with the key as a slice of integers.
 func (c *Context) GetIntSlice(key any) []int {
 	return getTyped[[]int](c, key)
@@ -451,6 +456,11 @@ func (c *Context) GetStringSlice(key any) []string {
 	return getTyped[[]string](c, key)
 }
 
+// GetErrorSlice returns the value associated with the key as a slice of errors.
+func (c *Context) GetErrorSlice(key any) []error {
+	return getTyped[[]error](c, key)
+}
+
 // GetStringMap returns the value associated with the key as a map of interfaces.
 func (c *Context) GetStringMap(key any) map[string]any {
 	return getTyped[map[string]any](c, key)

context_test.go

@@ -516,6 +516,14 @@ func TestContextGetDuration(t *testing.T) {
 	assert.Equal(t, time.Second, c.GetDuration("duration"))
 }
 
+func TestContextGetError(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	key := "error"
+	value := errors.New("test error")
+	c.Set(key, value)
+	assert.Equal(t, value, c.GetError(key))
+}
+
 func TestContextGetIntSlice(t *testing.T) {
 	c, _ := CreateTestContext(httptest.NewRecorder())
 	key := "int-slice"
@@ -618,6 +626,14 @@ func TestContextGetStringSlice(t *testing.T) {
 	assert.Equal(t, []string{"foo"}, c.GetStringSlice("slice"))
 }
 
+func TestContextGetErrorSlice(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	key := "error-slice"
+	value := []error{errors.New("error1"), errors.New("error2")}
+	c.Set(key, value)
+	assert.Equal(t, value, c.GetErrorSlice(key))
+}
+
 func TestContextGetStringMap(t *testing.T) {
 	c, _ := CreateTestContext(httptest.NewRecorder())
 	m := make(map[string]any)