fix(tui): open workflow children as full pages

extensions/shared/agent-session-page.test.ts

@@ -0,0 +1,83 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import type {
+  KeybindingsManager,
+  Theme,
+} from "@earendil-works/pi-coding-agent";
+import { initTheme } from "@earendil-works/pi-coding-agent";
+import { visibleWidth, type TUI } from "@earendil-works/pi-tui";
+import {
+  AgentSessionPage,
+  type AgentSessionPageState,
+} from "./agent-session-page.ts";
+
+initTheme("dark", false);
+
+const theme = {
+  fg: (_color: string, text: string) => text,
+  bold: (text: string) => text,
+  italic: (text: string) => text,
+} as Theme;
+
+const keybindings = {
+  matches(data: string, binding: string) {
+    return data === binding.replace("tui.editor.cursor", "").toLowerCase();
+  },
+  getKeys(binding: string) {
+    return [binding.split(".").at(-1)?.toLowerCase() ?? binding];
+  },
+} as unknown as KeybindingsManager;
+
+function tui(rows: number) {
+  return { terminal: { rows }, requestRender() {} } as unknown as TUI;
+}
+
+function state(): AgentSessionPageState {
+  return {
+    id: "child-1",
+    title: "child session",
+    status: "running",
+    metadata: ["model", "12%/100k"],
+    document: {
+      items: [
+        { kind: "user", text: "Inspect the page" },
+        { kind: "assistant", parts: [{ type: "text", text: "## Result" }] },
+      ],
+    },
+  };
+}
+
+test("writable and read-only children use one full-terminal page", () => {
+  const direct = new AgentSessionPage(tui(18), theme, keybindings, {
+    getState: state,
+    close() {},
+    send() {},
+  });
+  const workflow = new AgentSessionPage(tui(18), theme, keybindings, {
+    getState: state,
+    close() {},
+  });
+
+  const directLines = direct.render(60);
+  const workflowLines = workflow.render(60);
+  for (const lines of [directLines, workflowLines]) {
+    assert.equal(lines.length, 18);
+    assert.ok(lines.every((line) => visibleWidth(line) <= 60));
+    assert.match(lines.join("\n"), /> Inspect the page/);
+    assert.match(lines.join("\n"), /Result/);
+    assert.doesNotMatch(lines.join("\n"), /╭|╮|Transcript/);
+  }
+});
+
+test("a read-only Workflow child returns left without stealing a parent session", () => {
+  let closed = 0;
+  const page = new AgentSessionPage(tui(18), theme, keybindings, {
+    getState: state,
+    close: () => {
+      closed += 1;
+    },
+  });
+
+  page.handleInput("left");
+  assert.equal(closed, 1);
+});