perf(hass): ♻️ rework request logic

- response interface now expects to be able to represent an error
- responses can unmarshal a the raw response into their own error type for later usage
- update response structs to satisfy new response interface

internal/hass/config.go

@@ -3,6 +3,7 @@
 // This software is released under the MIT License.
 // https://opensource.org/licenses/MIT
 
+//nolint:errname // structs are dual-purpose response and error
 //revive:disable:unused-receiver
 package hass
 
@@ -20,7 +21,8 @@ var ErrLoadPrefsFailed = errors.New("could not load preferences")
 
 type Config struct {
 	Details *ConfigEntries
-	mu      sync.Mutex
+	*APIError
+	mu sync.Mutex
 }
 
 type ConfigEntries struct {
@@ -69,6 +71,19 @@ func (c *Config) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+func (c *Config) UnmarshalError(data []byte) error {
+	err := json.Unmarshal(data, c.APIError)
+	if err != nil {
+		return fmt.Errorf("could not unmarshal: %w", err)
+	}
+
+	return nil
+}
+
+func (c *Config) Error() string {
+	return c.APIError.Error()
+}
+
 type configRequest struct{}
 
 func (c *configRequest) RequestBody() json.RawMessage {

internal/hass/registration.go

@@ -3,6 +3,7 @@
 // This software is released under the MIT License.
 // https://opensource.org/licenses/MIT
 
+//nolint:errname // structs are dual-purpose response and error
 package hass
 
 import (
@@ -93,6 +94,7 @@ func newRegistrationRequest(info *DeviceInfo, token string) *registrationRequest
 
 type registrationResponse struct {
 	Details *RegistrationDetails
+	*APIError
 }
 
 func (r *registrationResponse) UnmarshalJSON(b []byte) error {
@@ -104,6 +106,19 @@ func (r *registrationResponse) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+func (r *registrationResponse) UnmarshalError(data []byte) error {
+	err := json.Unmarshal(data, r.APIError)
+	if err != nil {
+		return fmt.Errorf("could not unmarshal: %w", err)
+	}
+
+	return nil
+}
+
+func (r *registrationResponse) Error() string {
+	return r.APIError.Error()
+}
+
 //nolint:exhaustruct
 func newRegistrationResponse() *registrationResponse {
 	return &registrationResponse{}

internal/hass/registration_test.go

@@ -29,14 +29,24 @@ var mockDevInfo = &DeviceInfo{
 	SupportsEncryption: false,
 }
 
+//nolint:errname
 type failedResponse struct {
 	Details *RegistrationDetails
+	*APIError
 }
 
 func (r *failedResponse) UnmarshalJSON(b []byte) error {
 	return json.Unmarshal(b, &r.Details)
 }
 
+func (r *failedResponse) UnmarshalError(b []byte) error {
+	return json.Unmarshal(b, r.APIError)
+}
+
+func (r *failedResponse) Error() string {
+	return r.APIError.Error()
+}
+
 // setup creates a context using a test http client and server which will
 // return the given response when the ExecuteRequest function is called.
 var setupTestServer = func(t *testing.T, response Response) *httptest.Server {

internal/hass/request.go

@@ -23,9 +23,10 @@ var (
 	ErrInvalidURL        = errors.New("invalid URL")
 	ErrInvalidClient     = errors.New("invalid client")
 	ErrResponseMalformed = errors.New("malformed response")
-	ErrNoPrefs           = errors.New("loading preferences failed")
-	defaultTimeout       = 30 * time.Second
-	defaultRetry         = func(r *resty.Response, _ error) bool {
+	ErrUnknown           = errors.New("unknown error occurred")
+
+	defaultTimeout = 30 * time.Second
+	defaultRetry   = func(r *resty.Response, _ error) bool {
 		return r.StatusCode() == http.StatusTooManyRequests
 	}
 )
@@ -76,6 +77,8 @@ type Encrypted interface {
 //go:generate moq -out mock_Response_test.go . Response
 type Response interface {
 	json.Unmarshaler
+	UnmarshalError(data []byte) error
+	error
 }
 
 // ExecuteRequest sends an API request to Home Assistant. It supports either the
@@ -84,23 +87,17 @@ type Response interface {
 // satisfy the PostRequest interface. To add authentication where required,
 // satisfy the Auth interface. To send an encrypted request, satisfy the Secret
 // interface.
-//
-//nolint:exhaustruct
 func ExecuteRequest(ctx context.Context, client *resty.Client, url string, request any, response Response) error {
 	if client == nil {
 		return ErrInvalidClient
 	}
 
-	// ?: handle nil response here
-	var responseErr *APIError
-
 	var resp *resty.Response
 
 	var err error
 
 	webClient := client.R().
-		SetContext(ctx).
-		SetError(&responseErr)
+		SetContext(ctx)
 	if a, ok := request.(Authenticated); ok {
 		webClient = webClient.SetAuthToken(a.Auth())
 	}
@@ -123,6 +120,7 @@ func ExecuteRequest(ctx context.Context, client *resty.Client, url string, reque
 		resp, err = webClient.Get(url)
 	}
 
+	// If the client fails to send the request, return a wrapped error.
 	if err != nil {
 		return fmt.Errorf("could not send request: %w", err)
 	}
@@ -136,21 +134,20 @@ func ExecuteRequest(ctx context.Context, client *resty.Client, url string, reque
 		RawJSON("body", resp.Body()).
 		Msg("Response received.")
 
+	// If the response is an error code, unmarshal it with the error method.
 	if resp.IsError() {
-		if responseErr != nil {
-			responseErr.StatusCode = resp.StatusCode()
-
-			return responseErr
+		if err := response.UnmarshalError(resp.Body()); err != nil {
+			return ErrUnknown
 		}
 
-		return &APIError{
-			StatusCode: resp.StatusCode(),
-			Message:    resp.Status(),
-		}
+		return response
 	}
-
-	if err := response.UnmarshalJSON(resp.Body()); err != nil {
-		return errors.Join(ErrResponseMalformed, err)
+	// Otherwise for a successful response, if the response body is not an empty
+	// string, unmarshal it.
+	if string(resp.Body()) != "" {
+		if err := response.UnmarshalJSON(resp.Body()); err != nil {
+			return errors.Join(ErrResponseMalformed, err)
+		}
 	}
 
 	return nil

internal/hass/request_test.go

@@ -94,6 +94,10 @@ func TestExecuteRequest(t *testing.T) {
 	badPostReq := PostRequestMock{
 		RequestBodyFunc: func() json.RawMessage { return json.RawMessage(`{"field":"value"}`) },
 	}
+	badPostResp := &ResponseMock{
+		UnmarshalErrorFunc: func(_ []byte) error { return nil },
+		ErrorFunc:          func() string { return "400 Bad Request" },
+	}
 
 	// badPostResp := &APIError{
 	// 	StatusCode: 400,
@@ -133,19 +137,13 @@ func TestExecuteRequest(t *testing.T) {
 		},
 		{
 			name: "invalid post request",
-			args: args{ctx: context.TODO(), client: NewDefaultHTTPClient(mockServer.URL), url: "/badPost", request: badPostReq, response: &ResponseMock{}},
-			want: &APIError{
-				StatusCode: 400,
-				Message:    "400 Bad Request",
-			},
+			args: args{ctx: context.TODO(), client: NewDefaultHTTPClient(mockServer.URL), url: "/badPost", request: badPostReq, response: badPostResp},
+			want: badPostResp,
 		},
 		{
 			name: "invalid get request",
-			args: args{ctx: context.TODO(), client: NewDefaultHTTPClient(mockServer.URL), url: "/badGet", request: "anything", response: &ResponseMock{}},
-			want: &APIError{
-				StatusCode: 400,
-				Message:    "400 Bad Request",
-			},
+			args: args{ctx: context.TODO(), client: NewDefaultHTTPClient(mockServer.URL), url: "/badGet", request: "anything", response: badPostResp},
+			want: badPostResp,
 		},
 		// {
 		// 	name: "badData",