Fix memory leak in dev server

src/commands/start/index.ts

@@ -7,9 +7,8 @@ import { existsSync, rmSync } from "fs";
 
 const { BUNX_BUNDLER_ERROR_EXIT_FILE } = grabDirNames();
 
-let retries = 0;
-let timeout: any;
 const MAX_RETRIES = 5;
+const RETRY_RESET_AFTER_MS = 10000;
 
 export default function () {
     return new Command("start")
@@ -24,59 +23,60 @@ export default function () {
 }
 
 async function start() {
-    clearTimeout(timeout);
+    // A loop, not recursion: each restart would otherwise keep the previous
+    // call (and its subprocess) alive for the supervisor's whole lifetime.
+    let retries = 0;
 
-    if (retries >= MAX_RETRIES) {
-        console.error(
-            `Production server crashed ${MAX_RETRIES} times. Exiting.`,
-        );
-        process.exit(1);
+    while (true) {
+        if (retries >= MAX_RETRIES) {
+            console.error(
+                `Production server crashed ${MAX_RETRIES} times. Exiting.`,
+            );
+            process.exit(1);
+        }
+
+        const prod_spawn_file = path.resolve(__dirname, "prod-spawn.ts");
+        const prod_spawn_js_file = path.resolve(__dirname, "prod-spawn.js");
+
+        const final_spawn_file = existsSync(prod_spawn_js_file)
+            ? prod_spawn_js_file
+            : prod_spawn_file;
+
+        const spawn_options: BunSpawnOptions = {
+            cmd: ["bun", final_spawn_file],
+            stdio: ["inherit", "inherit", "inherit"],
+            onExit(subprocess, exitCode, signalCode, error) {
+                writeErrorFile({ exitCode, error });
+            },
+            env: {
+                ...process.env,
+                NODE_ENV: "production",
+            },
+        };
+
+        const started_at = Date.now();
+
+        let child_process;
+        try {
+            child_process = Bun.spawn(spawn_options);
+        } catch (error) {
+            console.error(`Failed to start production process:`, error);
+            retries++;
+            continue;
+        }
+
+        const exited = await child_process.exited;
+
+        // A null exit means the child was killed by a signal (e.g. Ctrl+C
+        // in the shared terminal), which we must not restart.
+        if (exited == null) {
+            return;
+        }
+
+        // Restart on any numeric exit (0 included: the server should never
+        // exit cleanly). Only consecutive quick crashes count toward the
+        // limit; a child that ran for a while starts the count over.
+        retries =
+            Date.now() - started_at >= RETRY_RESET_AFTER_MS ? 1 : retries + 1;
     }
-
-    const prod_spawn_file = path.resolve(__dirname, "prod-spawn.ts");
-    const prod_spawn_js_file = path.resolve(__dirname, "prod-spawn.js");
-
-    const final_spawn_file = existsSync(prod_spawn_js_file)
-        ? prod_spawn_js_file
-        : prod_spawn_file;
-
-    const spawn_options: BunSpawnOptions = {
-        cmd: ["bun", final_spawn_file],
-        stdio: ["inherit", "inherit", "inherit"],
-        onExit(subprocess, exitCode, signalCode, error) {
-            writeErrorFile({ exitCode, error });
-        },
-        env: {
-            ...process.env,
-            NODE_ENV: "production",
-        },
-    };
-
-    let dev_process;
-    try {
-        dev_process = Bun.spawn(spawn_options);
-    } catch (error) {
-        console.error(`Failed to start production process:`, error);
-        retries++;
-        timeout = setTimeout(() => {
-            retries = 0;
-        }, 10000);
-        return await start();
-    }
-
-    const exited = await dev_process.exited;
-
-    // Restart on any numeric exit (0 included). A null exit means the child
-    // was killed by a signal, which we must not restart.
-    if (exited != null) {
-        retries++;
-        timeout = setTimeout(() => {
-            retries = 0;
-        }, 10000);
-        return await start();
-    }
-
-    timeout = setTimeout(() => {
-        retries = 0;
-    }, 10000);
 }