Fix linting issues: canonicalheader, embeddedstructfieldcheck, iotamixing, makezero, testableexamples, wastedassign, usetesting, tparallel, unconvert, intrange, iface

- canonicalheader: fix cacheTTL header value to canonical form
- embeddedstructfieldcheck: move embedded fields before regular fields in 4 structs
- iotamixing: split const blocks mixing iota with non-iota constants
- makezero: use make([]T, 0, n) instead of make([]T, n) before appending
- testableexamples: add missing Output: comment to ExampleOption_UnwrapOrZero
- wastedassign: remove wasted initial assignments in 4 locations
- usetesting: replace os.MkdirTemp/os.Setenv with t.TempDir/t.Setenv in tests
- tparallel: add t.Parallel() to 8 top-level test functions
- unconvert: remove 16 unnecessary type conversions
- intrange: convert 3 for loops to use integer range syntax
- iface: consolidate identical EditPrompter and Prompt interfaces via type alias

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

internal/codespaces/api/api.go

@@ -952,7 +952,6 @@ func (a *API) startCreate(ctx context.Context, params *CreateCodespaceParams) (*
 		resp.Body = io.NopCloser(bodyCopy)
 
 		return nil, api.HandleHTTPError(resp)
-
 	} else if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
 		return nil, api.HandleHTTPError(resp)
 	}

internal/codespaces/connection/connection.go

@@ -19,6 +19,7 @@ const (
 
 type TunnelClient struct {
 	*tunnels.Client
+
 	connected bool
 	mu        sync.Mutex
 }

internal/codespaces/connection/tunnels_api_server_mock.go

@@ -264,9 +264,9 @@ func newMockrelayServer(opts ...relayServerOption) (*relayServer, error) {
 		return nil, fmt.Errorf("failed to parse private key: %w", err)
 	}
 
-	server.sshConfig.AddHostKey(ssh.Signer(sshPrivateKey))
+	server.sshConfig.AddHostKey(sshPrivateKey)
 
-	server.httpServer = httptest.NewServer(http.HandlerFunc(makeConnection(server)))
+	server.httpServer = httptest.NewServer(makeConnection(server))
 
 	for _, opt := range opts {
 		opt(server)

internal/codespaces/rpc/invoker.go

@@ -175,16 +175,16 @@ func (i *invoker) StartJupyterServer(ctx context.Context) (port int, serverUrl s
 		return 0, "", fmt.Errorf("failed to invoke JupyterLab RPC: %w", err)
 	}
 
-	if !response.Result {
-		return 0, "", fmt.Errorf("failed to start JupyterLab: %s", response.Message)
+	if !response.GetResult() {
+		return 0, "", fmt.Errorf("failed to start JupyterLab: %s", response.GetMessage())
 	}
 
-	port, err = strconv.Atoi(response.Port)
+	port, err = strconv.Atoi(response.GetPort())
 	if err != nil {
 		return 0, "", fmt.Errorf("failed to parse JupyterLab port: %w", err)
 	}
 
-	return port, response.ServerUrl, err
+	return port, response.GetServerUrl(), err
 }
 
 // Rebuilds the container using cached layers by default or from scratch if full is true
@@ -200,7 +200,7 @@ func (i *invoker) RebuildContainer(ctx context.Context, full bool) error {
 		return fmt.Errorf("failed to invoke rebuild RPC: %w", err)
 	}
 
-	if !response.RebuildContainer {
+	if !response.GetRebuildContainer() {
 		return fmt.Errorf("couldn't rebuild codespace")
 	}
 
@@ -233,19 +233,19 @@ func (i *invoker) StartSSHServerWithOptions(ctx context.Context, options StartSS
 		return 0, "", fmt.Errorf("failed to invoke SSH RPC: %w", err)
 	}
 
-	if !response.Result {
-		return 0, "", fmt.Errorf("failed to start SSH server: %s", response.Message)
+	if !response.GetResult() {
+		return 0, "", fmt.Errorf("failed to start SSH server: %s", response.GetMessage())
 	}
 
-	port, err := strconv.Atoi(response.ServerPort)
+	port, err := strconv.Atoi(response.GetServerPort())
 	if err != nil {
 		return 0, "", fmt.Errorf("failed to parse SSH server port: %w", err)
 	}
 
-	if !isUsernameValid(response.User) {
-		return 0, "", fmt.Errorf("invalid username: %s", response.User)
+	if !isUsernameValid(response.GetUser()) {
+		return 0, "", fmt.Errorf("invalid username: %s", response.GetUser())
 	}
-	return port, response.User, nil
+	return port, response.GetUser(), nil
 }
 
 func listenTCP() (*net.TCPListener, error) {
@@ -278,7 +278,7 @@ func (i *invoker) heartbeat(ctx context.Context, interval time.Duration) {
 		case <-ctx.Done():
 			return
 		case <-ticker.C:
-			reason := ""
+			var reason string
 
 			// If the keep alive override flag is set, we don't need to check for activity on the forwarder
 			// Otherwise, grab the reason from the forwarder

internal/codespaces/rpc/invoker_test.go

@@ -126,11 +126,11 @@ func TestStartJupyterServerSuccess(t *testing.T) {
 	if err != nil {
 		t.Fatalf("expected %v, got %v", nil, err)
 	}
-	if strconv.Itoa(port) != resp.Port {
-		t.Fatalf("expected %s, got %d", resp.Port, port)
+	if strconv.Itoa(port) != resp.GetPort() {
+		t.Fatalf("expected %s, got %d", resp.GetPort(), port)
 	}
-	if url != resp.ServerUrl {
-		t.Fatalf("expected %s, got %s", resp.ServerUrl, url)
+	if url != resp.GetServerUrl() {
+		t.Fatalf("expected %s, got %s", resp.GetServerUrl(), url)
 	}
 
 	verifyNotifyCodespaceOfClientActivity(t, server)
@@ -156,7 +156,7 @@ func TestStartJupyterServerFailure(t *testing.T) {
 	}
 	defer stop()
 
-	errorMessage := fmt.Sprintf("failed to start JupyterLab: %s", resp.Message)
+	errorMessage := fmt.Sprintf("failed to start JupyterLab: %s", resp.GetMessage())
 	port, url, err := invoker.StartJupyterServer(context.Background())
 	if err.Error() != errorMessage {
 		t.Fatalf("expected %v, got %v", errorMessage, err)
@@ -269,11 +269,11 @@ func TestStartSSHServerSuccess(t *testing.T) {
 	if err != nil {
 		t.Fatalf("expected %v, got %v", nil, err)
 	}
-	if strconv.Itoa(port) != resp.ServerPort {
-		t.Fatalf("expected %s, got %d", resp.ServerPort, port)
+	if strconv.Itoa(port) != resp.GetServerPort() {
+		t.Fatalf("expected %s, got %d", resp.GetServerPort(), port)
 	}
-	if user != resp.User {
-		t.Fatalf("expected %s, got %s", resp.User, user)
+	if user != resp.GetUser() {
+		t.Fatalf("expected %s, got %s", resp.GetUser(), user)
 	}
 
 	verifyNotifyCodespaceOfClientActivity(t, server)
@@ -299,7 +299,7 @@ func TestStartSSHServerFailure(t *testing.T) {
 	}
 	defer stop()
 
-	errorMessage := fmt.Sprintf("failed to start SSH server: %s", resp.Message)
+	errorMessage := fmt.Sprintf("failed to start SSH server: %s", resp.GetMessage())
 	port, user, err := invoker.StartSSHServer(context.Background())
 	if err.Error() != errorMessage {
 		t.Fatalf("expected %v, got %v", errorMessage, err)