refactor: detect session changes by identity and queue re-fetches

Address round 3 review feedback on the session-state architecture:

- Drop the revision counter and the lean WorkspaceSessionSnapshot
  projection in favor of comparing SessionData by identity; every
  sign-in/sign-out already creates a new object, so the revision
  tracked the same information twice.
- Move the session-state contract into the deployment layer
  (SessionState in sessionStore.ts) and expose it through
  deploymentManager.sessionState, so the workspace tree depends on
  deployment state rather than the other way around.
- Replace the bounded in-fetch retry loop with a queued re-fetch:
  fetchAndRefresh() calls that land mid-flight (session changes,
  manual refreshes) mark a pending re-fetch that runs once the current
  fetch settles. Stale results are dropped instead of retried inline,
  requests never run in parallel, and a fetch that fails after a
  session change is now retried instead of leaving the tree empty.

Author: EhabY

src/deployment/deploymentManager.ts

@@ -17,7 +17,11 @@ import { type OAuthSessionManager } from "../oauth/sessionManager";
 import { getAuthConfigWatchSettings } from "../settings/authConfig";
 import { type TelemetryService } from "../telemetry/service";
 
-import { SessionStore, type SessionData } from "./sessionStore";
+import {
+	SessionStore,
+	type SessionData,
+	type SessionState,
+} from "./sessionStore";
 import {
 	DeploymentSchema,
 	type Deployment,
@@ -27,11 +31,6 @@ import {
 import type { User } from "coder/site/src/api/typesGenerated";
 import type * as vscode from "vscode";
 
-import type {
-	WorkspaceSessionSnapshot,
-	WorkspaceSessionState,
-} from "../workspace/session";
-
 /**
  * Manages deployment state for the extension.
  *
@@ -43,9 +42,7 @@ import type {
  * - Context updates (coder.authenticated, coder.isOwner)
  * - Cross-window sync handling
  */
-export class DeploymentManager
-	implements vscode.Disposable, WorkspaceSessionState
-{
+export class DeploymentManager implements vscode.Disposable {
 	private readonly secretsManager: SecretsManager;
 	private readonly mementoManager: MementoManager;
 	private readonly contextManager: ContextManager;
@@ -54,7 +51,8 @@ export class DeploymentManager
 	private readonly deploymentTelemetry: DeploymentTelemetry;
 
 	readonly #sessionStore = new SessionStore();
-	public readonly onDidChange = this.#sessionStore.onDidChange;
+	/** Read-only session view for consumers that track auth changes. */
+	public readonly sessionState: SessionState = this.#sessionStore;
 	#disposed = false;
 	#authListenerDisposable: vscode.Disposable | undefined;
 	#authConfigDisposable: vscode.Disposable | undefined;
@@ -97,10 +95,6 @@ export class DeploymentManager
 		return this.#sessionStore.current.deployment;
 	}
 
-	public getSnapshot(): WorkspaceSessionSnapshot {
-		return this.#sessionStore.getSnapshot();
-	}
-
 	/**
 	 * Check if we have an authenticated deployment (does not guarantee that the current auth data is valid).
 	 */

src/deployment/sessionStore.ts

@@ -2,11 +2,6 @@ import * as vscode from "vscode";
 
 import type { User } from "coder/site/src/api/typesGenerated";
 
-import type {
-	WorkspaceSessionSnapshot,
-	WorkspaceSessionState,
-} from "../workspace/session";
-
 import type { Deployment } from "./types";
 
 /**
@@ -25,36 +20,31 @@ export type SessionData =
 	  };
 
 /**
- * Owns the deployment session. State changes only through signIn()/signOut(),
- * each of which bumps the revision and notifies listeners.
+ * Read-only session access: the current data plus change notifications.
  *
- * Consumers that only need auth status (like the workspace tree) take the lean
- * WorkspaceSessionState projection instead of the full session.
+ * To detect a change across an await, keep the SessionData read before the
+ * await and compare it by identity afterward; sign-in and sign-out always
+ * replace the object.
  */
-export class SessionStore implements WorkspaceSessionState {
+export interface SessionState {
+	readonly current: SessionData;
+	readonly onDidChange: vscode.Event<SessionData>;
+}
+
+/**
+ * Owns the deployment session. State changes only through signIn()/signOut(),
+ * each of which replaces the session object and notifies listeners.
+ */
+export class SessionStore implements SessionState {
 	#data: SessionData = { kind: "signedOut", deployment: null };
-	#revision = 0;
-	readonly #onDidChange = new vscode.EventEmitter<WorkspaceSessionSnapshot>();
+	readonly #onDidChange = new vscode.EventEmitter<SessionData>();
 
 	public readonly onDidChange = this.#onDidChange.event;
 
-	/** Full session state, including deployment and user. */
 	public get current(): SessionData {
 		return this.#data;
 	}
 
-	/** Lean projection for consumers that only track auth status and revision. */
-	public getSnapshot(): WorkspaceSessionSnapshot {
-		if (this.#data.kind === "signedIn") {
-			return {
-				kind: "signedIn",
-				revision: this.#revision,
-				userId: this.#data.user.id,
-			};
-		}
-		return { kind: "signedOut", revision: this.#revision };
-	}
-
 	public signIn(deployment: Deployment, user: User): SessionData {
 		return this.transition({ kind: "signedIn", deployment, user });
 	}
@@ -65,8 +55,7 @@ export class SessionStore implements WorkspaceSessionState {
 
 	private transition(data: SessionData): SessionData {
 		this.#data = data;
-		this.#revision++;
-		this.#onDidChange.fire(this.getSnapshot());
+		this.#onDidChange.fire(data);
 		return data;
 	}
 

src/extension.ts

@@ -166,7 +166,7 @@ async function doActivate(
 		WorkspaceQuery.Mine,
 		client,
 		output,
-		deploymentManager,
+		deploymentManager.sessionState,
 		{ refreshIntervalMs: 5_000 },
 	);
 	ctx.subscriptions.push(myWorkspacesProvider);
@@ -175,15 +175,15 @@ async function doActivate(
 		WorkspaceQuery.All,
 		client,
 		output,
-		deploymentManager,
+		deploymentManager.sessionState,
 	);
 	ctx.subscriptions.push(allWorkspacesProvider);
 
 	const sharedWorkspacesProvider = new WorkspaceProvider(
 		WorkspaceQuery.Shared,
 		client,
 		output,
-		deploymentManager,
+		deploymentManager.sessionState,
 	);
 	ctx.subscriptions.push(sharedWorkspacesProvider);