Refactor: use var for local variable type inference

Apply Java var (local variable type inference) across the codebase where
the type is obvious from the right-hand side expression:
- Constructor calls: Type x = new Type() -> var x = new Type()
- Diamond operator fill: List<X> x = new ArrayList<>() -> var x = new ArrayList<X>()
- Cast expressions: Type x = (Type) expr -> var x = (Type) expr

Modified 3 main source files and 14 test files (17 files total).

Author: brunoborges

src/main/java/com/github/copilot/sdk/CopilotClient.java

@@ -281,14 +281,13 @@ private void handleToolCall(JsonRpcClient rpc, String requestId, JsonNode params
 
                 ToolDefinition tool = session.getTool(toolName);
                 if (tool == null || tool.getHandler() == null) {
-                    ToolResultObject result = new ToolResultObject()
-                            .setTextResultForLlm("Tool '" + toolName + "' is not supported.").setResultType("failure")
-                            .setError("tool '" + toolName + "' not supported");
+                    var result = new ToolResultObject().setTextResultForLlm("Tool '" + toolName + "' is not supported.")
+                            .setResultType("failure").setError("tool '" + toolName + "' not supported");
                     rpc.sendResponse(Long.parseLong(requestId), Map.of("result", result));
                     return;
                 }
 
-                ToolInvocation invocation = new ToolInvocation().setSessionId(sessionId).setToolCallId(toolCallId)
+                var invocation = new ToolInvocation().setSessionId(sessionId).setToolCallId(toolCallId)
                         .setToolName(toolName).setArguments(arguments);
 
                 tool.getHandler().invoke(invocation).thenAccept(result -> {
@@ -306,7 +305,7 @@ private void handleToolCall(JsonRpcClient rpc, String requestId, JsonNode params
                     }
                 }).exceptionally(ex -> {
                     try {
-                        ToolResultObject result = new ToolResultObject()
+                        var result = new ToolResultObject()
                                 .setTextResultForLlm(
                                         "Invoking this tool produced an error. Detailed information is not available.")
                                 .setResultType("failure").setError(ex.getMessage());
@@ -335,7 +334,7 @@ private void handlePermissionRequest(JsonRpcClient rpc, String requestId, JsonNo
 
                 CopilotSession session = sessions.get(sessionId);
                 if (session == null) {
-                    PermissionRequestResult result = new PermissionRequestResult()
+                    var result = new PermissionRequestResult()
                             .setKind("denied-no-approval-rule-and-could-not-request-from-user");
                     rpc.sendResponse(Long.parseLong(requestId), Map.of("result", result));
                     return;
@@ -349,7 +348,7 @@ private void handlePermissionRequest(JsonRpcClient rpc, String requestId, JsonNo
                     }
                 }).exceptionally(ex -> {
                     try {
-                        PermissionRequestResult result = new PermissionRequestResult()
+                        var result = new PermissionRequestResult()
                                 .setKind("denied-no-approval-rule-and-could-not-request-from-user");
                         rpc.sendResponse(Long.parseLong(requestId), Map.of("result", result));
                     } catch (IOException e) {
@@ -381,10 +380,9 @@ private void handleUserInputRequest(JsonRpcClient rpc, String requestId, JsonNod
                     return;
                 }
 
-                com.github.copilot.sdk.json.UserInputRequest request = new com.github.copilot.sdk.json.UserInputRequest()
-                        .setQuestion(question);
+                var request = new com.github.copilot.sdk.json.UserInputRequest().setQuestion(question);
                 if (choicesNode != null && choicesNode.isArray()) {
-                    List<String> choices = new ArrayList<>();
+                    var choices = new ArrayList<String>();
                     for (JsonNode choice : choicesNode) {
                         choices.add(choice.asText());
                     }
@@ -461,7 +459,7 @@ private void handleHooksInvoke(JsonRpcClient rpc, String requestId, JsonNode par
 
     private void verifyProtocolVersion(Connection connection) throws Exception {
         int expectedVersion = SdkProtocolVersion.get();
-        Map<String, Object> params = new HashMap<>();
+        var params = new HashMap<String, Object>();
         params.put("message", null);
         PingResponse pingResponse = connection.rpc.invoke("ping", params, PingResponse.class).get(30, TimeUnit.SECONDS);
 
@@ -484,7 +482,7 @@ private void verifyProtocolVersion(Connection connection) throws Exception {
      * @return A future that completes when the client is stopped
      */
     public CompletableFuture<Void> stop() {
-        List<CompletableFuture<Void>> closeFutures = new ArrayList<>();
+        var closeFutures = new ArrayList<CompletableFuture<Void>>();
 
         for (CopilotSession session : new ArrayList<>(sessions.values())) {
             closeFutures.add(CompletableFuture.runAsync(() -> {
@@ -555,7 +553,7 @@ private CompletableFuture<Void> cleanupConnection() {
      */
     public CompletableFuture<CopilotSession> createSession(SessionConfig config) {
         return ensureConnected().thenCompose(connection -> {
-            CreateSessionRequest request = new CreateSessionRequest();
+            var request = new CreateSessionRequest();
             if (config != null) {
                 request.setModel(config.getModel());
                 request.setSessionId(config.getSessionId());
@@ -585,8 +583,7 @@ public CompletableFuture<CopilotSession> createSession(SessionConfig config) {
             }
 
             return connection.rpc.invoke("session.create", request, CreateSessionResponse.class).thenApply(response -> {
-                CopilotSession session = new CopilotSession(response.getSessionId(), connection.rpc,
-                        response.getWorkspacePath());
+                var session = new CopilotSession(response.getSessionId(), connection.rpc, response.getWorkspacePath());
                 if (config != null && config.getTools() != null) {
                     session.registerTools(config.getTools());
                 }
@@ -632,7 +629,7 @@ public CompletableFuture<CopilotSession> createSession() {
      */
     public CompletableFuture<CopilotSession> resumeSession(String sessionId, ResumeSessionConfig config) {
         return ensureConnected().thenCompose(connection -> {
-            ResumeSessionRequest request = new ResumeSessionRequest();
+            var request = new ResumeSessionRequest();
             request.setSessionId(sessionId);
             if (config != null) {
                 request.setReasoningEffort(config.getReasoningEffort());
@@ -655,8 +652,7 @@ public CompletableFuture<CopilotSession> resumeSession(String sessionId, ResumeS
             }
 
             return connection.rpc.invoke("session.resume", request, ResumeSessionResponse.class).thenApply(response -> {
-                CopilotSession session = new CopilotSession(response.getSessionId(), connection.rpc,
-                        response.getWorkspacePath());
+                var session = new CopilotSession(response.getSessionId(), connection.rpc, response.getWorkspacePath());
                 if (config != null && config.getTools() != null) {
                     session.registerTools(config.getTools());
                 }
@@ -960,7 +956,7 @@ private CompletableFuture<Connection> ensureConnected() {
 
     private ProcessInfo startCliServer() throws IOException, InterruptedException {
         String cliPath = options.getCliPath() != null ? options.getCliPath() : "copilot";
-        List<String> args = new ArrayList<>();
+        var args = new ArrayList<String>();
 
         if (options.getCliArgs() != null) {
             args.addAll(Arrays.asList(options.getCliArgs()));
@@ -993,7 +989,7 @@ private ProcessInfo startCliServer() throws IOException, InterruptedException {
 
         List<String> command = resolveCliCommand(cliPath, args);
 
-        ProcessBuilder pb = new ProcessBuilder(command);
+        var pb = new ProcessBuilder(command);
         pb.redirectErrorStream(false);
 
         if (options.getCwd() != null) {
@@ -1014,7 +1010,7 @@ private ProcessInfo startCliServer() throws IOException, InterruptedException {
         Process process = pb.start();
 
         // Forward stderr to logger in background
-        Thread stderrThread = new Thread(() -> {
+        var stderrThread = new Thread(() -> {
             try (BufferedReader reader = new BufferedReader(
                     new InputStreamReader(process.getErrorStream(), StandardCharsets.UTF_8))) {
                 String line;
@@ -1063,7 +1059,7 @@ private List<String> resolveCliCommand(String cliPath, List<String> args) {
         boolean isJsFile = cliPath.toLowerCase().endsWith(".js");
 
         if (isJsFile) {
-            List<String> result = new ArrayList<>();
+            var result = new ArrayList<String>();
             result.add("node");
             result.add(cliPath);
             result.addAll(args);
@@ -1073,15 +1069,15 @@ private List<String> resolveCliCommand(String cliPath, List<String> args) {
         // On Windows, use cmd /c to resolve the executable
         String os = System.getProperty("os.name").toLowerCase();
         if (os.contains("win") && !new File(cliPath).isAbsolute()) {
-            List<String> result = new ArrayList<>();
+            var result = new ArrayList<String>();
             result.add("cmd");
             result.add("/c");
             result.add(cliPath);
             result.addAll(args);
             return result;
         }
 
-        List<String> result = new ArrayList<>();
+        var result = new ArrayList<String>();
         result.add(cliPath);
         result.addAll(args);
         return result;

src/main/java/com/github/copilot/sdk/CopilotSession.java

@@ -13,7 +13,6 @@
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicReference;
@@ -196,7 +195,7 @@ public CompletableFuture<AssistantMessageEvent> sendAndWait(String prompt) {
      * @see #send(String)
      */
     public CompletableFuture<String> send(MessageOptions options) {
-        SendMessageRequest request = new SendMessageRequest();
+        var request = new SendMessageRequest();
         request.setSessionId(sessionId);
         request.setPrompt(options.getPrompt());
         request.setAttachments(options.getAttachments());
@@ -225,8 +224,8 @@ public CompletableFuture<String> send(MessageOptions options) {
      * @see #send(MessageOptions)
      */
     public CompletableFuture<AssistantMessageEvent> sendAndWait(MessageOptions options, long timeoutMs) {
-        CompletableFuture<AssistantMessageEvent> future = new CompletableFuture<>();
-        AtomicReference<AssistantMessageEvent> lastAssistantMessage = new AtomicReference<>();
+        var future = new CompletableFuture<AssistantMessageEvent>();
+        var lastAssistantMessage = new AtomicReference<AssistantMessageEvent>();
 
         Consumer<AbstractSessionEvent> handler = evt -> {
             if (evt instanceof AssistantMessageEvent msg) {
@@ -252,8 +251,8 @@ public CompletableFuture<AssistantMessageEvent> sendAndWait(MessageOptions optio
         });
 
         // Set up timeout with daemon thread so it doesn't prevent JVM exit
-        ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor(r -> {
-            Thread t = new Thread(r, "sendAndWait-timeout");
+        var scheduler = Executors.newSingleThreadScheduledExecutor(r -> {
+            var t = new Thread(r, "sendAndWait-timeout");
             t.setDaemon(true);
             return t;
         });
@@ -444,7 +443,7 @@ CompletableFuture<PermissionRequestResult> handlePermissionRequest(JsonNode perm
 
         try {
             PermissionRequest request = MAPPER.treeToValue(permissionRequestData, PermissionRequest.class);
-            PermissionInvocation invocation = new PermissionInvocation();
+            var invocation = new PermissionInvocation();
             invocation.setSessionId(sessionId);
             return handler.handle(request, invocation).exceptionally(ex -> {
                 LOG.log(Level.SEVERE, "Permission handler threw an exception", ex);
@@ -489,7 +488,7 @@ CompletableFuture<UserInputResponse> handleUserInputRequest(UserInputRequest req
         }
 
         try {
-            UserInputInvocation invocation = new UserInputInvocation().setSessionId(sessionId);
+            var invocation = new UserInputInvocation().setSessionId(sessionId);
             return handler.handle(request, invocation).exceptionally(ex -> {
                 LOG.log(Level.SEVERE, "User input handler threw an exception", ex);
                 throw new RuntimeException("User input handler error", ex);
@@ -529,7 +528,7 @@ CompletableFuture<Object> handleHooksInvoke(String hookType, JsonNode input) {
             return CompletableFuture.completedFuture(null);
         }
 
-        HookInvocation invocation = new HookInvocation().setSessionId(sessionId);
+        var invocation = new HookInvocation().setSessionId(sessionId);
 
         try {
             switch (hookType) {
@@ -592,7 +591,7 @@ CompletableFuture<Object> handleHooksInvoke(String hookType, JsonNode input) {
     public CompletableFuture<List<AbstractSessionEvent>> getMessages() {
         return rpc.invoke("session.getMessages", Map.of("sessionId", sessionId), GetMessagesResponse.class)
                 .thenApply(response -> {
-                    List<AbstractSessionEvent> events = new ArrayList<>();
+                    var events = new ArrayList<AbstractSessionEvent>();
                     if (response.getEvents() != null) {
                         for (JsonNode eventNode : response.getEvents()) {
                             try {

src/main/java/com/github/copilot/sdk/JsonRpcClient.java

@@ -66,7 +66,7 @@ private JsonRpcClient(InputStream inputStream, OutputStream outputStream, Socket
     }
 
     static ObjectMapper createObjectMapper() {
-        ObjectMapper mapper = new ObjectMapper();
+        var mapper = new ObjectMapper();
         mapper.registerModule(new JavaTimeModule());
         mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
         mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
@@ -105,10 +105,10 @@ public void registerMethodHandler(String method, BiConsumer<String, JsonNode> ha
      */
     public <T> CompletableFuture<T> invoke(String method, Object params, Class<T> responseType) {
         long id = requestIdCounter.incrementAndGet();
-        CompletableFuture<JsonNode> future = new CompletableFuture<>();
+        var future = new CompletableFuture<JsonNode>();
         pendingRequests.put(id, future);
 
-        JsonRpcRequest request = new JsonRpcRequest();
+        var request = new JsonRpcRequest();
         request.setJsonrpc("2.0");
         request.setId(id);
         request.setMethod(method);
@@ -137,7 +137,7 @@ public <T> CompletableFuture<T> invoke(String method, Object params, Class<T> re
      * Sends a JSON-RPC notification (no response expected).
      */
     public void notify(String method, Object params) throws IOException {
-        JsonRpcRequest notification = new JsonRpcRequest();
+        var notification = new JsonRpcRequest();
         notification.setJsonrpc("2.0");
         notification.setMethod(method);
         notification.setParams(params);
@@ -148,7 +148,7 @@ public void notify(String method, Object params) throws IOException {
      * Sends a JSON-RPC response to a server request.
      */
     public void sendResponse(Object id, Object result) throws IOException {
-        JsonRpcResponse response = new JsonRpcResponse();
+        var response = new JsonRpcResponse();
         response.setJsonrpc("2.0");
         response.setId(id);
         response.setResult(result);
@@ -159,10 +159,10 @@ public void sendResponse(Object id, Object result) throws IOException {
      * Sends a JSON-RPC error response to a server request.
      */
     public void sendErrorResponse(Object id, int code, String message) throws IOException {
-        JsonRpcResponse response = new JsonRpcResponse();
+        var response = new JsonRpcResponse();
         response.setJsonrpc("2.0");
         response.setId(id);
-        JsonRpcError error = new JsonRpcError();
+        var error = new JsonRpcError();
         error.setCode(code);
         error.setMessage(message);
         response.setError(error);
@@ -186,12 +186,12 @@ private void startReader() {
             try {
                 // We need to read bytes because Content-Length specifies bytes, not characters.
                 // Using BufferedReader would cause issues with multi-byte UTF-8 characters.
-                BufferedInputStream bis = new BufferedInputStream(inputStream);
+                var bis = new BufferedInputStream(inputStream);
 
                 while (running) {
                     // Read headers line by line
                     int contentLength = -1;
-                    StringBuilder headerLine = new StringBuilder();
+                    var headerLine = new StringBuilder();
                     boolean lastWasCR = false;
                     boolean inHeaders = true;
 

src/test/java/com/github/copilot/sdk/AskUserTest.java

@@ -7,7 +7,6 @@
 import static org.junit.jupiter.api.Assertions.*;
 
 import java.util.ArrayList;
-import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 
@@ -54,10 +53,10 @@ static void teardown() throws Exception {
     void testShouldInvokeUserInputHandlerWhenModelUsesAskUserTool() throws Exception {
         ctx.configureForTest("ask_user", "should_invoke_user_input_handler_when_model_uses_ask_user_tool");
 
-        List<UserInputRequest> userInputRequests = new ArrayList<>();
+        var userInputRequests = new ArrayList<UserInputRequest>();
         final String[] sessionIdHolder = new String[1];
 
-        SessionConfig config = new SessionConfig().setOnUserInputRequest((request, invocation) -> {
+        var config = new SessionConfig().setOnUserInputRequest((request, invocation) -> {
             userInputRequests.add(request);
             assertEquals(sessionIdHolder[0], invocation.getSessionId());
 
@@ -97,9 +96,9 @@ void testShouldInvokeUserInputHandlerWhenModelUsesAskUserTool() throws Exception
     void testShouldReceiveChoicesInUserInputRequest() throws Exception {
         ctx.configureForTest("ask_user", "should_receive_choices_in_user_input_request");
 
-        List<UserInputRequest> userInputRequests = new ArrayList<>();
+        var userInputRequests = new ArrayList<UserInputRequest>();
 
-        SessionConfig config = new SessionConfig().setOnUserInputRequest((request, invocation) -> {
+        var config = new SessionConfig().setOnUserInputRequest((request, invocation) -> {
             userInputRequests.add(request);
 
             // Pick the first choice
@@ -135,10 +134,10 @@ void testShouldReceiveChoicesInUserInputRequest() throws Exception {
     void testShouldHandleFreeformUserInputResponse() throws Exception {
         ctx.configureForTest("ask_user", "should_handle_freeform_user_input_response");
 
-        final List<UserInputRequest> userInputRequests = new ArrayList<>();
+        final var userInputRequests = new ArrayList<UserInputRequest>();
         String freeformAnswer = "This is my custom freeform answer that was not in the choices";
 
-        SessionConfig config = new SessionConfig().setOnUserInputRequest((request, invocation) -> {
+        var config = new SessionConfig().setOnUserInputRequest((request, invocation) -> {
             userInputRequests.add(request);
 
             // Return a freeform answer (not from choices)

src/test/java/com/github/copilot/sdk/CapiProxy.java

@@ -89,7 +89,7 @@ public String start() throws IOException, InterruptedException {
         }
 
         // Start the harness server using npx tsx
-        ProcessBuilder pb = new ProcessBuilder("npx", "tsx", "server.ts");
+        var pb = new ProcessBuilder("npx", "tsx", "server.ts");
         pb.directory(harnessDir.toFile());
         pb.redirectErrorStream(false);