Organize composer into its own module

packages/app/src/composer/draft/workspace-tab.test.ts

@@ -0,0 +1,51 @@
+import { describe, expect, test } from "vitest";
+
+import { validateDraftSubmission } from "./workspace-tab-core";
+
+const baseComposerState = {
+  providerDefinitions: [{ id: "deepseek-tui" }],
+  selectedProvider: "deepseek-tui",
+  isModelLoading: false,
+  effectiveModelId: "",
+  availableModels: [],
+};
+
+function validate(overrides = {}) {
+  return validateDraftSubmission({
+    text: "hello",
+    allowsEmptyAutoSubmit: false,
+    composerState: baseComposerState,
+    autoSubmitConfig: null,
+    workspaceDirectory: "/tmp/project",
+    hasClient: true,
+    ...overrides,
+  });
+}
+
+describe("workspace draft agent model validation", () => {
+  test("allows a ready provider with no models to submit without a selected model", () => {
+    expect(validate({})).toBeNull();
+  });
+
+  test("keeps waiting while model defaults are loading", () => {
+    expect(
+      validate({
+        composerState: {
+          ...baseComposerState,
+          isModelLoading: true,
+        },
+      }),
+    ).toBe("Model defaults are still loading");
+  });
+
+  test("still requires a selected model when the provider exposes models", () => {
+    expect(
+      validate({
+        composerState: {
+          ...baseComposerState,
+          availableModels: [{ id: "deepseek/deepseek-v4-pro" }],
+        },
+      }),
+    ).toBe("No model is available for the selected provider");
+  });
+});