release: subagent live progress + transcript (#594)

lib/agent/messageMetadata/__tests__/sumLanguageModelUsage.test.ts

@@ -0,0 +1,27 @@
+import { describe, it, expect } from "vitest";
+import { sumLanguageModelUsage } from "@/lib/agent/messageMetadata/sumLanguageModelUsage";
+
+describe("sumLanguageModelUsage", () => {
+  it("returns undefined when both inputs are undefined", () => {
+    expect(sumLanguageModelUsage(undefined, undefined)).toBeUndefined();
+  });
+
+  it("returns the second input when first is undefined", () => {
+    const u = { inputTokens: 100, outputTokens: 50 };
+    expect(sumLanguageModelUsage(undefined, u as never)).toBe(u);
+  });
+
+  it("returns the first input when second is undefined", () => {
+    const u = { inputTokens: 100, outputTokens: 50 };
+    expect(sumLanguageModelUsage(u as never, undefined)).toBe(u);
+  });
+
+  it("sums the two inputs pointwise when both are present", () => {
+    const result = sumLanguageModelUsage(
+      { inputTokens: 100, outputTokens: 50 } as never,
+      { inputTokens: 200, outputTokens: 75 } as never,
+    );
+    expect(result?.inputTokens).toBe(300);
+    expect(result?.outputTokens).toBe(125);
+  });
+});

lib/agent/messageMetadata/sumLanguageModelUsage.ts

@@ -0,0 +1,21 @@
+import type { LanguageModelUsage } from "ai";
+import { addLanguageModelUsage } from "@/lib/agent/messageMetadata/addLanguageModelUsage";
+
+/**
+ * Sum two optional `LanguageModelUsage` records. Returns the sum when
+ * both are defined, the defined one when only one is, or `undefined`
+ * when neither is. Mirrors open-agents' `sumLanguageModelUsage` in
+ * `packages/agent/usage.ts`.
+ *
+ * Used by the `task` tool's progress streaming to accumulate usage
+ * across subagent steps without introducing zero-tokens placeholders
+ * before the first step finishes.
+ */
+export function sumLanguageModelUsage(
+  a: LanguageModelUsage | undefined,
+  b: LanguageModelUsage | undefined,
+): LanguageModelUsage | undefined {
+  if (!a) return b;
+  if (!b) return a;
+  return addLanguageModelUsage(a, b);
+}

lib/agent/tools/__tests__/askUserQuestionTool.test.ts

@@ -81,14 +81,16 @@ describe("askUserQuestionTool — server-side wiring", () => {
 
 describe("askUserQuestionTool.toModelOutput", () => {
   it("returns a generic message when no output is present", () => {
-    expect(askUserQuestionTool.toModelOutput!(undefined as never)).toEqual({
+    expect(askUserQuestionTool.toModelOutput!({ output: undefined } as never)).toEqual({
       type: "text",
       value: "User did not respond to questions.",
     });
   });
 
   it("formats `declined: true` as a clear decline message", () => {
-    const result = askUserQuestionTool.toModelOutput!({ declined: true } as never);
+    const result = askUserQuestionTool.toModelOutput!({
+      output: { declined: true },
+    } as never);
     expect(result).toMatchObject({
       type: "text",
       value: expect.stringMatching(/declined to answer/i),
@@ -97,9 +99,11 @@ describe("askUserQuestionTool.toModelOutput", () => {
 
   it("formats answered questions as a parseable Q=A summary", () => {
     const result = askUserQuestionTool.toModelOutput!({
-      answers: {
-        "Which model do you want?": "Haiku",
-        "Which features?": ["Streaming", "Tools"],
+      output: {
+        answers: {
+          "Which model do you want?": "Haiku",
+          "Which features?": ["Streaming", "Tools"],
+        },
       },
     } as never);
     expect(result).toMatchObject({