Squashed 'third_party/pi/' content from commit d981de122

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

packages/telemetry/test/conformance.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, it } from "vitest";
+import { InMemoryTelemetryContext, type SpanAttributes } from "../src/index.ts";
+import { createTelemetryAdapterConformance, type TelemetryAdapterFixture } from "../src/testing/index.ts";
+
+const conformance = createTelemetryAdapterConformance(() => {
+	const context = new InMemoryTelemetryContext();
+	return Promise.resolve<TelemetryAdapterFixture>({
+		context,
+		getSpans: () => Promise.resolve(context.getSpans()),
+		[Symbol.asyncDispose]: () => Promise.resolve(),
+	});
+});
+
+describe("InMemoryTelemetryContext conformance", () => {
+	for (const group of new Set(conformance.map((testCase) => testCase.group))) {
+		describe(group, () => {
+			for (const testCase of conformance.filter((candidate) => candidate.group === group)) {
+				it(testCase.name, () => testCase.run());
+			}
+		});
+	}
+
+	it("returns detached snapshots without exposing mutable recording state", async () => {
+		const context = new InMemoryTelemetryContext();
+		let openSettled: boolean | undefined;
+		let openEndSequence: number | undefined;
+		await context.startSpan({ name: "snapshot", attributes: { tags: ["initial"] } }, (span) => {
+			span.addEvent("event", { value: 1 });
+			const [open] = context.getSpans();
+			openSettled = open?.settled;
+			openEndSequence = open?.endSequence;
+		});
+
+		expect(openSettled).toBe(false);
+		expect(openEndSequence).toBeUndefined();
+		const [first] = context.getSpans();
+		expect(first?.settled).toBe(true);
+		expect(first?.endSequence).toBe(1);
+		(first?.attributes as SpanAttributes).tags = ["mutated"];
+		(first?.events[0]?.attributes as SpanAttributes).value = 2;
+
+		const [second] = context.getSpans();
+		expect(second?.attributes).toEqual({ tags: ["initial"] });
+		expect(second?.events).toEqual([{ name: "event", attributes: { value: 1 } }]);
+	});
+});