workspace: retry ready after failed connect

Clear the cached ready promise when a connection attempt rejects so later ready, push, pull, or exec calls can rebuild the backend session. Add a regression test for a flaky backend that succeeds after an initial failure.

Author: aron-cf

packages/workspace/src/workspace.test.ts

@@ -154,6 +154,28 @@ describe("Workspace backend fallback", () => {
     await expect(ws.ready()).rejects.toThrow(/boom[\s\S]*kaboom/);
   });
 
+  it("does not cache a failed ready() attempt", async () => {
+    let attempts = 0;
+    const backend: WorkspaceBackend = {
+      id: "flaky",
+      async connect() {
+        attempts++;
+        if (attempts === 1) throw new Error("temporary container disconnect");
+        return {
+          rpc: composite(fakeRpc()),
+          close: async () => {},
+        };
+      },
+    };
+    const ws = new Workspace({ storage: makeStorage(), backends: [backend] });
+
+    await expect(ws.ready()).rejects.toThrow(/temporary container disconnect/);
+    await ws.ready();
+
+    expect(attempts).toBe(2);
+    expect(ws.shell).toBeDefined();
+  });
+
   it("ready() is idempotent — subsequent calls reuse the same connection", async () => {
     const backend = makeBackend("only");
     const spy = vi.spyOn(backend, "connect");

packages/workspace/src/workspace.ts

@@ -219,14 +219,21 @@ export class Workspace {
   // the same in-flight connection attempt.
   ready(): Promise<void> {
     if (this.#readyPromise) return this.#readyPromise;
-    this.#readyPromise = (async () => {
+    const ready = (async () => {
       await this.#connect();
       // Index after the backend is wired so reads of mounted paths
       // are populated before the first push() inside an exec()
       // bracket can ship them.
       await this.#mountIndex.ensureIndexed();
     })();
-    return this.#readyPromise;
+    this.#readyPromise = ready;
+    ready.catch(() => {
+      // A failed connection attempt must not poison this Workspace forever.
+      // The next ready()/push()/pull()/exec should re-enter #connect(), giving
+      // backend factories a chance to pick a fresh transport.
+      if (this.#readyPromise === ready) this.#readyPromise = undefined;
+    });
+    return ready;
   }
 
   // Wrap this workspace in a WorkspaceStub so it can be handed