fix: Fix mcp console focus stealing (#396)

Author: Daniel McIlvaney

.vscode/mcp.json

@@ -3,17 +3,22 @@
         "azldev-mage-builder": {
             "type": "stdio",
             "command": "go",
-            "args": ["run", "-C", "./magefiles/magemcp/", "magemcp.go", "${workspaceFolder}"],
+            "args": [
+                "run",
+                "-C",
+                "./magefiles/magemcp/",
+                "magemcp.go",
+                "${workspaceFolder}"
+            ],
             "cwd": "${workspaceFolder}"
         },
         "run-azldev-from-out-bin": {
             "type": "stdio",
-            "command": "./out/bin/azldev",
-            "args": ["advanced", "mcp"],
-            "cwd": "${workspaceFolder}",
-            "dev": {
-                "watch": "out/bin/azldev"
-            }
+            "command": "bash",
+            "args": [
+                ".vscode/run-azldev-mcp.sh"
+            ],
+            "cwd": "${workspaceFolder}"
         }
     }
 }

.vscode/run-azldev-mcp.sh

@@ -0,0 +1,107 @@
+#!/usr/bin/env bash
+
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# Wrapper for the azldev MCP server with inotify-based auto-restart.
+#
+# - Uses out/bin/azldev if it exists, otherwise falls back to 'go run'.
+# - Watches for binary changes via inotifywait and restarts automatically.
+# - Falls back to plain exec (no auto-restart) if inotifywait is unavailable.
+#
+# A wrapper is needed instead of using vscode's "dev" flag directly because it triggers every time the binary
+# is built, and this causes the MCP server's output console to grab focus and interrupt the developer's workflow.
+#
+# Install inotify-tools for auto-restart:
+#   sudo dnf install inotify-tools    (Fedora/RHEL)
+#   sudo apt install inotify-tools    (Debian/Ubuntu)
+
+set -uo pipefail
+
+BINARY="./out/bin/azldev"
+BINARY_DIR="$(dirname "$BINARY")"
+SERVER_PID=""
+WATCH_PID=""
+
+# Save original stdin to fd 3. Bash redirects background processes' stdin to
+# /dev/null, so we need to explicitly restore it for the MCP server which
+# communicates over stdio.
+exec 3<&0
+
+cleanup() {
+    [[ -n "$SERVER_PID" ]] && kill "$SERVER_PID" 2>/dev/null
+    [[ -n "$WATCH_PID" ]] && kill "$WATCH_PID" 2>/dev/null
+    wait 2>/dev/null
+}
+trap cleanup EXIT SIGTERM SIGINT
+
+# Start the server in the background and save its PID.
+start_server() {
+    if [[ -x "$BINARY" ]]; then
+        echo "Starting azldev MCP server from $BINARY..." >&2
+        "$BINARY" advanced mcp 0<&3 &
+    else
+        echo "Binary not found; running azldev MCP server via 'go run'..." >&2
+        go run ./cmd/azldev advanced mcp 0<&3 &
+    fi
+    SERVER_PID=$!
+}
+
+# Completely replace the current process with the server (no auto-restart).
+replace_server() {
+    if [[ -x "$BINARY" ]]; then
+        echo "Starting azldev MCP server from $BINARY..." >&2
+        exec "$BINARY" advanced mcp 0<&3
+    else
+        echo "Binary not found; running azldev MCP server via 'go run'..." >&2
+        exec go run ./cmd/azldev advanced mcp 0<&3
+    fi
+     # No return expected since exec replaces the shell
+}
+
+# No inotifywait → run directly without auto-restart.
+if ! command -v inotifywait &>/dev/null; then
+    echo "inotifywait not found; running without auto-restart. Install inotify-tools for auto-restart." >&2
+    replace_server
+fi
+
+while true; do
+    start_server
+
+    # Watch the directory for the binary being created/replaced.
+    # go build writes to a temp file then renames, so watching the file
+    # directly misses the event (inode changes).
+    (
+        while true; do
+            while [[ ! -d "$BINARY_DIR" ]]; do sleep 2; done
+            inotifywait -qq -e close_write -e moved_to -e create "$BINARY_DIR" 2>/dev/null
+            # Only restart if the actual binary was affected.
+            if [[ -x "$BINARY" ]]; then
+                break
+            fi
+        done
+    ) &
+    WATCH_PID=$!
+
+    # Wait for either the server to exit or the file watcher to trigger.
+    wait -n "$SERVER_PID" "$WATCH_PID" 2>/dev/null || true
+
+    if ! kill -0 "$SERVER_PID" 2>/dev/null; then
+        # Server exited on its own → clean up watcher and exit.
+        kill "$WATCH_PID" 2>/dev/null || true
+        wait "$WATCH_PID" 2>/dev/null || true
+        echo "azldev MCP server exited" >&2
+        exit 1
+    fi
+
+    # Binary changed → kill server and restart after debounce.
+    kill "$WATCH_PID" 2>/dev/null || true
+    wait "$WATCH_PID" 2>/dev/null || true
+
+    # Debounce: wait for file activity to settle (go build does multiple ops).
+    sleep 1
+
+    kill "$SERVER_PID" 2>/dev/null || true
+    wait "$SERVER_PID" 2>/dev/null || true
+    echo "azldev MCP server restarted (binary changed)" >&2
+done