Squashed 'third_party/pi/' content from commit d981de122

git-subtree-dir: third_party/pi
git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

packages/agent/test/harness/context.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import {
+	BACKGROUND_CONTEXT,
+	getTelemetryContext,
+	TODO_CONTEXT,
+	withTelemetryContext,
+} from "../../src/harness/context.ts";
+import { InMemoryTelemetryContext, NOOP_TELEMETRY_CONTEXT } from "../../src/index.ts";
+
+describe("harness Context telemetry", () => {
+	it("uses no-op telemetry when none is attached", () => {
+		expect(getTelemetryContext(BACKGROUND_CONTEXT)).toBe(NOOP_TELEMETRY_CONTEXT);
+		expect(getTelemetryContext(TODO_CONTEXT)).toBe(NOOP_TELEMETRY_CONTEXT);
+	});
+
+	it("carries telemetry as an ordinary context value", async () => {
+		const telemetry = new InMemoryTelemetryContext();
+		const context = withTelemetryContext(telemetry, BACKGROUND_CONTEXT);
+
+		await getTelemetryContext(context).startSpan({ name: "parent" }, async (span) => {
+			const childContext = withTelemetryContext(span, context);
+			await getTelemetryContext(childContext).startSpan({ name: "child" }, () => undefined);
+		});
+
+		const spans = telemetry.getSpans();
+		expect(spans.map((span) => span.name)).toEqual(["parent", "child"]);
+		expect(spans[1]?.parentId).toBe(spans[0]?.id);
+	});
+});