🤖 refactor: simplify ssh runtime scaling flow

Author: ammar-agent

src/node/runtime/RemoteRuntime.test.ts

@@ -33,8 +33,7 @@ class TestRemoteRuntime extends RemoteRuntime {
   constructor(
     private readonly childProcess: FakeChildProcess,
     private readonly onExitCalls: Array<[number, string]>,
-    private readonly onCloseCalls: number[],
-    private readonly onExitCodeCalls: number[]
+    private readonly onCloseCalls: number[]
   ) {
     super();
   }
@@ -66,10 +65,6 @@ class TestRemoteRuntime extends RemoteRuntime {
     return `cd ${cwd}`;
   }
 
-  protected override onExitCode(exitCode: number): void {
-    this.onExitCodeCalls.push(exitCode);
-  }
-
   resolvePath(targetPath: string): Promise<string> {
     return Promise.resolve(targetPath);
   }
@@ -108,8 +103,7 @@ describe("RemoteRuntime synthetic exit handling", () => {
     const childProcess = new FakeChildProcess();
     const onExitCalls: Array<[number, string]> = [];
     const onCloseCalls: number[] = [];
-    const onExitCodeCalls: number[] = [];
-    const runtime = new TestRemoteRuntime(childProcess, onExitCalls, onCloseCalls, onExitCodeCalls);
+    const runtime = new TestRemoteRuntime(childProcess, onExitCalls, onCloseCalls);
     const controller = new AbortController();
 
     const stream = await runtime.exec("echo ok", { cwd: "/tmp", abortSignal: controller.signal });
@@ -119,15 +113,13 @@ describe("RemoteRuntime synthetic exit handling", () => {
     expect(await stream.exitCode).toBe(EXIT_CODE_ABORTED);
     expect(onExitCalls).toEqual([]);
     expect(onCloseCalls).toEqual([1]);
-    expect(onExitCodeCalls).toEqual([EXIT_CODE_ABORTED]);
   });
 
   test("does not forward timed-out exits to transport onExit hooks", async () => {
     const childProcess = new FakeChildProcess();
     const onExitCalls: Array<[number, string]> = [];
     const onCloseCalls: number[] = [];
-    const onExitCodeCalls: number[] = [];
-    const runtime = new TestRemoteRuntime(childProcess, onExitCalls, onCloseCalls, onExitCodeCalls);
+    const runtime = new TestRemoteRuntime(childProcess, onExitCalls, onCloseCalls);
 
     const stream = await runtime.exec("echo ok", { cwd: "/tmp", timeout: 0.01 });
     await new Promise((resolve) => setTimeout(resolve, 20));
@@ -136,6 +128,5 @@ describe("RemoteRuntime synthetic exit handling", () => {
     expect(await stream.exitCode).toBe(EXIT_CODE_TIMEOUT);
     expect(onExitCalls).toEqual([]);
     expect(onCloseCalls).toEqual([1]);
-    expect(onExitCodeCalls).toEqual([EXIT_CODE_TIMEOUT]);
   });
 });

src/node/runtime/RemoteRuntime.ts

@@ -11,7 +11,6 @@
  * - spawnRemoteProcess() - how to spawn the external process (ssh/docker)
  * - getBasePath() - base directory for workspace operations
  * - quoteForRemote() - path quoting strategy
- * - onExitCode() - optional exit code handling (SSH connection pool)
  */
 
 import type { ChildProcess } from "child_process";
@@ -45,8 +44,6 @@ import { getAtomicWriteTempPath } from "./atomicWriteTempPath";
 export interface SpawnResult {
   /** The spawned child process */
   process: ChildProcess;
-  /** Optional async work to do before exec (e.g., acquire connection) */
-  preExec?: Promise<void>;
   /** Optional transport-scoped exit handling (e.g., master-pool health accounting). */
   onExit?: (exitCode: number, stderr: string) => void;
   /** Optional close handling that must run even for synthetic abort/timeout exits. */
@@ -65,7 +62,7 @@ export abstract class RemoteRuntime implements Runtime {
    *
    * @param fullCommand The full shell command to execute (already wrapped in bash -c)
    * @param options Original exec options
-   * @returns The spawned process and optional pre-exec work
+   * @returns The spawned process and optional transport lifecycle hooks
    */
   protected abstract spawnRemoteProcess(
     fullCommand: string,
@@ -90,15 +87,6 @@ export abstract class RemoteRuntime implements Runtime {
    */
   protected abstract cdCommand(cwd: string): string;
 
-  /**
-   * Called when exec completes with an exit code.
-   * Subclasses can use this for connection pool health tracking.
-   * @param stderr - Captured stderr for error reporting (e.g., SSH connection failures)
-   */
-  protected onExitCode(_exitCode: number, _options: ExecOptions, _stderr: string): void {
-    // Default: no-op. SSH overrides to report to connection pool.
-  }
-
   /**
    * Command prefix (e.g., "SSH" or "Docker") for logging.
    */
@@ -185,8 +173,6 @@ export abstract class RemoteRuntime implements Runtime {
           spawnResult.onExit?.(finalExitCode, stderrForErrorReporting);
         }
         spawnResult.onClose?.();
-        // Let subclass handle exit code (e.g., SSH connection pool)
-        this.onExitCode(finalExitCode, options, stderrForErrorReporting);
 
         resolve(finalExitCode);
       });