Merge pull request #91 from AutoMaker-Org/new-fixes-terminal

feat: enhance terminal functionality with debouncing and resize valid…

apps/server/src/index.ts

@@ -190,6 +190,18 @@ wss.on("connection", (ws: WebSocket) => {
 
 // Track WebSocket connections per session
 const terminalConnections: Map<string, Set<WebSocket>> = new Map();
+// Track last resize dimensions per session to deduplicate resize messages
+const lastResizeDimensions: Map<string, { cols: number; rows: number }> = new Map();
+// Track last resize timestamp to rate-limit resize operations (prevents resize storm)
+const lastResizeTime: Map<string, number> = new Map();
+const RESIZE_MIN_INTERVAL_MS = 100; // Minimum 100ms between resize operations
+
+// Clean up resize tracking when sessions actually exit (not just when connections close)
+terminalService.onExit((sessionId) => {
+  lastResizeDimensions.delete(sessionId);
+  lastResizeTime.delete(sessionId);
+  terminalConnections.delete(sessionId);
+});
 
 // Terminal WebSocket connection handler
 terminalWss.on(
@@ -241,7 +253,29 @@ terminalWss.on(
     }
     terminalConnections.get(sessionId)!.add(ws);
 
-    // Subscribe to terminal data
+    // Send initial connection success FIRST
+    ws.send(
+      JSON.stringify({
+        type: "connected",
+        sessionId,
+        shell: session.shell,
+        cwd: session.cwd,
+      })
+    );
+
+    // Send scrollback buffer BEFORE subscribing to prevent race condition
+    // Also clear pending output buffer to prevent duplicates from throttled flush
+    const scrollback = terminalService.getScrollbackAndClearPending(sessionId);
+    if (scrollback && scrollback.length > 0) {
+      ws.send(
+        JSON.stringify({
+          type: "scrollback",
+          data: scrollback,
+        })
+      );
+    }
+
+    // NOW subscribe to terminal data (after scrollback is sent)
     const unsubscribeData = terminalService.onData((sid, data) => {
       if (sid === sessionId && ws.readyState === WebSocket.OPEN) {
         ws.send(JSON.stringify({ type: "data", data }));
@@ -268,9 +302,33 @@ terminalWss.on(
             break;
 
           case "resize":
-            // Resize terminal
+            // Resize terminal with deduplication and rate limiting
             if (msg.cols && msg.rows) {
-              terminalService.resize(sessionId, msg.cols, msg.rows);
+              const now = Date.now();
+              const lastTime = lastResizeTime.get(sessionId) || 0;
+              const lastDimensions = lastResizeDimensions.get(sessionId);
+
+              // Skip if resized too recently (prevents resize storm during splits)
+              if (now - lastTime < RESIZE_MIN_INTERVAL_MS) {
+                break;
+              }
+
+              // Check if dimensions are different from last resize
+              if (
+                !lastDimensions ||
+                lastDimensions.cols !== msg.cols ||
+                lastDimensions.rows !== msg.rows
+              ) {
+                // Only suppress output on subsequent resizes, not the first one
+                // The first resize happens on terminal open and we don't want to drop the initial prompt
+                const isFirstResize = !lastDimensions;
+                terminalService.resize(sessionId, msg.cols, msg.rows, !isFirstResize);
+                lastResizeDimensions.set(sessionId, {
+                  cols: msg.cols,
+                  rows: msg.rows,
+                });
+                lastResizeTime.set(sessionId, now);
+              }
             }
             break;
 
@@ -300,6 +358,10 @@ terminalWss.on(
         connections.delete(ws);
         if (connections.size === 0) {
           terminalConnections.delete(sessionId);
+          // DON'T delete lastResizeDimensions/lastResizeTime here!
+          // The session still exists, and reconnecting clients need to know
+          // this isn't the "first resize" to prevent duplicate prompts.
+          // These get cleaned up when the session actually exits.
         }
       }
     });
@@ -309,27 +371,6 @@ terminalWss.on(
       unsubscribeData();
       unsubscribeExit();
     });
-
-    // Send initial connection success
-    ws.send(
-      JSON.stringify({
-        type: "connected",
-        sessionId,
-        shell: session.shell,
-        cwd: session.cwd,
-      })
-    );
-
-    // Send scrollback buffer to replay previous output
-    const scrollback = terminalService.getScrollback(sessionId);
-    if (scrollback && scrollback.length > 0) {
-      ws.send(
-        JSON.stringify({
-          type: "scrollback",
-          data: scrollback,
-        })
-      );
-    }
   }
 );
 

apps/server/src/services/terminal-service.ts

@@ -26,6 +26,8 @@ export interface TerminalSession {
   scrollbackBuffer: string; // Store recent output for replay on reconnect
   outputBuffer: string; // Pending output to be flushed
   flushTimeout: NodeJS.Timeout | null; // Throttle timer
+  resizeInProgress: boolean; // Flag to suppress scrollback during resize
+  resizeDebounceTimeout: NodeJS.Timeout | null; // Resize settle timer
 }
 
 export interface TerminalOptions {
@@ -213,6 +215,8 @@ export class TerminalService extends EventEmitter {
       scrollbackBuffer: "",
       outputBuffer: "",
       flushTimeout: null,
+      resizeInProgress: false,
+      resizeDebounceTimeout: null,
     };
 
     this.sessions.set(id, session);
@@ -239,6 +243,13 @@ export class TerminalService extends EventEmitter {
 
     // Forward data events with throttling
     ptyProcess.onData((data) => {
+      // Skip ALL output during resize/reconnect to prevent prompt redraw duplication
+      // This drops both scrollback AND live output during the suppression window
+      // Without this, prompt redraws from SIGWINCH go to live clients causing duplicates
+      if (session.resizeInProgress) {
+        return;
+      }
+
       // Append to scrollback buffer
       session.scrollbackBuffer += data;
       // Trim if too large (keep the most recent data)
@@ -246,7 +257,7 @@ export class TerminalService extends EventEmitter {
         session.scrollbackBuffer = session.scrollbackBuffer.slice(-MAX_SCROLLBACK_SIZE);
       }
 
-      // Buffer output for throttled delivery
+      // Buffer output for throttled live delivery
       session.outputBuffer += data;
 
       // Schedule flush if not already scheduled
@@ -282,18 +293,40 @@ export class TerminalService extends EventEmitter {
 
   /**
    * Resize a terminal session
+   * @param suppressOutput - If true, suppress output during resize to prevent duplicate prompts.
+   *                         Should be false for the initial resize so the first prompt isn't dropped.
    */
-  resize(sessionId: string, cols: number, rows: number): boolean {
+  resize(sessionId: string, cols: number, rows: number, suppressOutput: boolean = true): boolean {
     const session = this.sessions.get(sessionId);
     if (!session) {
       console.warn(`[Terminal] Session ${sessionId} not found for resize`);
       return false;
     }
     try {
+      // Only suppress output on subsequent resizes, not the initial one
+      // This prevents the shell's first prompt from being dropped
+      if (suppressOutput) {
+        session.resizeInProgress = true;
+        if (session.resizeDebounceTimeout) {
+          clearTimeout(session.resizeDebounceTimeout);
+        }
+      }
+
       session.pty.resize(cols, rows);
+
+      // Clear resize flag after a delay (allow prompt to settle)
+      // 150ms is enough for most prompts - longer causes sluggish feel
+      if (suppressOutput) {
+        session.resizeDebounceTimeout = setTimeout(() => {
+          session.resizeInProgress = false;
+          session.resizeDebounceTimeout = null;
+        }, 150);
+      }
+
       return true;
     } catch (error) {
       console.error(`[Terminal] Error resizing session ${sessionId}:`, error);
+      session.resizeInProgress = false; // Clear flag on error
       return false;
     }
   }
@@ -312,6 +345,11 @@ export class TerminalService extends EventEmitter {
         clearTimeout(session.flushTimeout);
         session.flushTimeout = null;
       }
+      // Clean up resize debounce timeout
+      if (session.resizeDebounceTimeout) {
+        clearTimeout(session.resizeDebounceTimeout);
+        session.resizeDebounceTimeout = null;
+      }
       session.pty.kill();
       this.sessions.delete(sessionId);
       console.log(`[Terminal] Session ${sessionId} killed`);
@@ -337,6 +375,30 @@ export class TerminalService extends EventEmitter {
     return session?.scrollbackBuffer || null;
   }
 
+  /**
+   * Get scrollback buffer and clear pending output buffer to prevent duplicates
+   * Call this when establishing a new WebSocket connection
+   * This prevents data that's already in scrollback from being sent again via data callback
+   */
+  getScrollbackAndClearPending(sessionId: string): string | null {
+    const session = this.sessions.get(sessionId);
+    if (!session) return null;
+
+    // Clear any pending output that hasn't been flushed yet
+    // This data is already in scrollbackBuffer
+    session.outputBuffer = "";
+    if (session.flushTimeout) {
+      clearTimeout(session.flushTimeout);
+      session.flushTimeout = null;
+    }
+
+    // NOTE: Don't set resizeInProgress here - it causes blank terminals
+    // if the shell hasn't output its prompt yet when WebSocket connects.
+    // The resize() method handles suppression during actual resize events.
+
+    return session.scrollbackBuffer || null;
+  }
+
   /**
    * Get all active sessions
    */