style: refactor Desktop client for readability and maintainability

internal/desktop/client.go

@@ -53,11 +53,10 @@ func NewClient(apiEndpoint string) *Client {
 	}
 	transport = otelhttp.NewTransport(transport)
 
-	c := &Client{
+	return &Client{
 		apiEndpoint: apiEndpoint,
 		client:      &http.Client{Transport: transport},
 	}
-	return c
 }
 
 func (c *Client) Endpoint() string {
@@ -76,18 +75,17 @@ type PingResponse struct {
 
 // Ping is a minimal API used to ensure that the server is available.
 func (c *Client) Ping(ctx context.Context) (*PingResponse, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, backendURL("/ping"), http.NoBody)
+	req, err := c.newRequest(ctx, http.MethodGet, "/ping", http.NoBody)
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		_ = resp.Body.Close()
-	}()
+	defer resp.Body.Close()
+
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
 	}
@@ -106,18 +104,17 @@ type FeatureFlagValue struct {
 }
 
 func (c *Client) FeatureFlags(ctx context.Context) (FeatureFlagResponse, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, backendURL("/features"), http.NoBody)
+	req, err := c.newRequest(ctx, http.MethodGet, "/features", http.NoBody)
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		_ = resp.Body.Close()
-	}()
+	defer resp.Body.Close()
+
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
 	}
@@ -137,18 +134,16 @@ type GetFileSharesConfigResponse struct {
 }
 
 func (c *Client) GetFileSharesConfig(ctx context.Context) (*GetFileSharesConfigResponse, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, backendURL("/mutagen/file-shares/config"), http.NoBody)
+	req, err := c.newRequest(ctx, http.MethodGet, "/mutagen/file-shares/config", http.NoBody)
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		_ = resp.Body.Close()
-	}()
+	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, newHTTPStatusCodeError(resp)
@@ -171,25 +166,28 @@ type CreateFileShareResponse struct {
 }
 
 func (c *Client) CreateFileShare(ctx context.Context, r CreateFileShareRequest) (*CreateFileShareResponse, error) {
-	rawBody, _ := json.Marshal(r)
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, backendURL("/mutagen/file-shares"), bytes.NewReader(rawBody))
+	rawBody, err := json.Marshal(r)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal request: %w", err)
+	}
+
+	req, err := c.newRequest(ctx, http.MethodPost, "/mutagen/file-shares", bytes.NewReader(rawBody))
 	if err != nil {
 		return nil, err
 	}
 	req.Header.Set("Content-Type", "application/json")
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		_ = resp.Body.Close()
-	}()
+	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
 		errBody, _ := io.ReadAll(resp.Body)
 		return nil, fmt.Errorf("unexpected status code %d: %s", resp.StatusCode, string(errBody))
 	}
+
 	var ret CreateFileShareResponse
 	if err := json.NewDecoder(resp.Body).Decode(&ret); err != nil {
 		return nil, err
@@ -216,18 +214,16 @@ type FileShareSession struct {
 }
 
 func (c *Client) ListFileShares(ctx context.Context) ([]FileShareSession, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, backendURL("/mutagen/file-shares"), http.NoBody)
+	req, err := c.newRequest(ctx, http.MethodGet, "/mutagen/file-shares", http.NoBody)
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		_ = resp.Body.Close()
-	}()
+	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
 		return nil, newHTTPStatusCodeError(resp)
@@ -241,18 +237,17 @@ func (c *Client) ListFileShares(ctx context.Context) ([]FileShareSession, error)
 }
 
 func (c *Client) DeleteFileShare(ctx context.Context, id string) error {
-	req, err := http.NewRequestWithContext(ctx, http.MethodDelete, backendURL("/mutagen/file-shares/"+id), http.NoBody)
+	req, err := c.newRequest(ctx, http.MethodDelete, "/mutagen/file-shares/"+id, http.NoBody)
 	if err != nil {
 		return err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return err
 	}
-	defer func() {
-		_ = resp.Body.Close()
-	}()
+	defer resp.Body.Close()
+
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		return newHTTPStatusCodeError(resp)
 	}
@@ -274,30 +269,25 @@ func newHTTPStatusCodeError(resp *http.Response) error {
 }
 
 func (c *Client) StreamFileShares(ctx context.Context) (<-chan EventMessage[[]FileShareSession], error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, backendURL("/mutagen/file-shares/stream"), http.NoBody)
+	req, err := c.newRequest(ctx, http.MethodGet, "/mutagen/file-shares/stream", http.NoBody)
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
 	resp, err := c.client.Do(req)
 	if err != nil {
 		return nil, err
 	}
 
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		defer func() {
-			_ = resp.Body.Close()
-		}()
+		_ = resp.Body.Close()
 		return nil, newHTTPStatusCodeError(resp)
 	}
 
 	events := make(chan EventMessage[[]FileShareSession])
 	go func(ctx context.Context) {
 		defer func() {
 			_ = resp.Body.Close()
-			for range events {
-				// drain the channel
-			}
 			close(events)
 		}()
 		if err := readEvents(ctx, resp.Body, events); err != nil {
@@ -334,6 +324,15 @@ func readEvents[T any](ctx context.Context, r io.Reader, events chan<- EventMess
 	}
 }
 
+func (c *Client) newRequest(ctx context.Context, method, path string, body io.Reader) (*http.Request, error) {
+	req, err := http.NewRequestWithContext(ctx, method, backendURL(path), body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("User-Agent", userAgent)
+	return req, nil
+}
+
 // backendURL generates a URL for the given API path.
 //
 // NOTE: Custom transport handles communication. The host is to create a valid