feat: Enhance NodeCG process management and add IPC security tests

src/main/nodecg/process-manager.ts

@@ -32,12 +32,14 @@ type NodecgProcessManagerDeps = {
 };
 
 export type NodecgProcessManager = {
-  startNodecgProcess: () => Promise<ChildProcess>;
+  startNodecgProcess: () => Promise<void>;
   waitForNodecgReady: (startTime: number) => Promise<void>;
   stopNodecgProcessGracefully: () => Promise<void>;
-  getProcess: () => ChildProcess | null;
+  getState: () => NodecgProcessState;
 };
 
+export type NodecgProcessState = "idle" | "starting" | "running" | "stopping" | "stopped" | "failed";
+
 export function createNodecgProcessManager({
   isDev,
   nodecgRootPath,
@@ -49,64 +51,97 @@ export function createNodecgProcessManager({
   const resolvedDeps = resolveDeps(deps);
 
   let nodecgProcess: ChildProcess | null = null;
+  let nodecgState: NodecgProcessState = "idle";
+  let startNodecgPromise: Promise<void> | null = null;
   let stopNodecgPromise: Promise<void> | null = null;
   let lastExit: { code: number | null; signal: NodeJS.Signals | null } | null = null;
   let lastStderrLine: string | null = null;
 
-  const startNodecgProcess = async (): Promise<ChildProcess> => {
-    // Fail fast with actionable errors before spawning child processes.
-    validateNodecgInstall(
-      nodecgRootPath,
-      appConfig.bundleName,
-      resolvedDeps.pathExists,
-      resolvedDeps.hasReadWriteAccess,
-    );
-
-    const portAsNumber = Number.parseInt(appConfig.nodecgPort, 10);
-    const isPortAvailable = await resolvedDeps.probePortAvailable(portAsNumber);
-    if (!isPortAvailable) {
-      throw new Error(
-        `Port ${appConfig.nodecgPort} is already in use. Stop the process using it or set NODECG_PORT before starting.`,
-      );
+  const startNodecgProcess = (): Promise<void> => {
+    if (nodecgProcess && nodecgState === "running") {
+      return Promise.resolve();
     }
 
-    const indexPath = path.join(nodecgRootPath, "index.js");
-    const child = resolvedDeps.spawnProcess(resolvedDeps.execPath, [indexPath], {
-      cwd: nodecgRootPath,
-      env: {
-        ...resolvedDeps.env,
-        NODE_ENV: isDev ? "development" : "production",
-        NODECG_PORT: appConfig.nodecgPort,
-        ELECTRON_RUN_AS_NODE: "1",
-      },
-      stdio: ["ignore", "pipe", "pipe"],
-      detached: resolvedDeps.platform !== "win32",
-      shell: false,
-      windowsHide: true,
-    });
+    if (startNodecgPromise) {
+      return startNodecgPromise;
+    }
 
-    child.stdout?.on("data", (chunk) => {
-      resolvedDeps.stdoutWrite(String(chunk));
-    });
+    if (nodecgState === "stopping") {
+      return Promise.reject(new Error("Cannot start NodeCG while shutdown is in progress."));
+    }
 
-    child.stderr?.on("data", (chunk) => {
-      const line = String(chunk);
-      lastStderrLine = line.trim().length > 0 ? line.trim() : lastStderrLine;
-      resolvedDeps.stderrWrite(line);
-    });
+    nodecgState = "starting";
+    startNodecgPromise = (async () => {
+      // Fail fast with actionable errors before spawning child processes.
+      validateNodecgInstall(
+        nodecgRootPath,
+        appConfig.bundleName,
+        resolvedDeps.pathExists,
+        resolvedDeps.hasReadWriteAccess,
+      );
 
-    log(`NodeCG started with pid=${child.pid} using ${NODE_RUNTIME_NAME}`);
+      const portAsNumber = Number.parseInt(appConfig.nodecgPort, 10);
+      const isPortAvailable = await resolvedDeps.probePortAvailable(portAsNumber);
+      if (!isPortAvailable) {
+        throw new Error(
+          `Port ${appConfig.nodecgPort} is already in use. Stop the process using it or set NODECG_PORT before starting.`,
+        );
+      }
 
-    child.on("exit", (code, signal) => {
-      log(`NodeCG exited code=${code} signal=${signal ?? "none"}`);
-      lastExit = { code, signal };
-      nodecgProcess = null;
-    });
+      const indexPath = path.join(nodecgRootPath, "index.js");
+      const child = resolvedDeps.spawnProcess(resolvedDeps.execPath, [indexPath], {
+        cwd: nodecgRootPath,
+        env: {
+          ...resolvedDeps.env,
+          NODE_ENV: isDev ? "development" : "production",
+          NODECG_PORT: appConfig.nodecgPort,
+          ELECTRON_RUN_AS_NODE: "1",
+        },
+        stdio: ["ignore", "pipe", "pipe"],
+        detached: resolvedDeps.platform !== "win32",
+        shell: false,
+        windowsHide: true,
+      });
 
-    lastExit = null;
-    lastStderrLine = null;
-    nodecgProcess = child;
-    return child;
+      child.stdout?.on("data", (chunk) => {
+        resolvedDeps.stdoutWrite(String(chunk));
+      });
+
+      child.stderr?.on("data", (chunk) => {
+        const line = String(chunk);
+        lastStderrLine = line.trim().length > 0 ? line.trim() : lastStderrLine;
+        resolvedDeps.stderrWrite(line);
+      });
+
+      log(`NodeCG started with pid=${child.pid} using ${NODE_RUNTIME_NAME}`);
+
+      child.on("exit", (code, signal) => {
+        log(`NodeCG exited code=${code} signal=${signal ?? "none"}`);
+        lastExit = { code, signal };
+
+        if (nodecgProcess === child) {
+          nodecgProcess = null;
+        }
+
+        if (nodecgState !== "stopping") {
+          nodecgState = code === 0 ? "stopped" : "failed";
+        }
+      });
+
+      lastExit = null;
+      lastStderrLine = null;
+      nodecgProcess = child;
+      nodecgState = "running";
+    })()
+      .catch((error: unknown) => {
+        nodecgState = "failed";
+        throw error;
+      })
+      .finally(() => {
+        startNodecgPromise = null;
+      });
+
+    return startNodecgPromise;
   };
 
   const waitForNodecgReady = async (startTime: number): Promise<void> => {
@@ -150,6 +185,7 @@ export function createNodecgProcessManager({
     }
 
     if (!nodecgProcess || nodecgProcess.killed) {
+      nodecgState = "stopped";
       return Promise.resolve();
     }
 
@@ -158,9 +194,12 @@ export function createNodecgProcessManager({
 
     if (typeof pid !== "number") {
       log("NodeCG pid unavailable, skipping graceful stop");
+      nodecgProcess = null;
+      nodecgState = "stopped";
       return Promise.resolve();
     }
 
+    nodecgState = "stopping";
     log(`Stopping NodeCG pid=${pid}`);
     killProcessTree(pid, "SIGTERM", {
       platform: resolvedDeps.platform,
@@ -183,6 +222,7 @@ export function createNodecgProcessManager({
           nodecgProcess = null;
         }
 
+        nodecgState = "stopped";
         stopNodecgPromise = null;
         resolve();
       };
@@ -215,7 +255,7 @@ export function createNodecgProcessManager({
     startNodecgProcess,
     waitForNodecgReady,
     stopNodecgProcessGracefully,
-    getProcess: () => nodecgProcess,
+    getState: () => nodecgState,
   };
 }