Initial Commit

packages/api-stack/api/api-migrations/tests/setup/polyfills.ts

@@ -0,0 +1,39 @@
+/**
+ * Test-environment setup for @suaveplan/api-migrations.
+ *
+ * Wires a real in-memory OpenTelemetry MeterProvider BEFORE any source
+ * module is imported, so the meter resolved at module load is the real
+ * provider's meter — not the noop fallback. Tests that inspect emitted
+ * metrics (counter `migrations.applied_total`, histogram
+ * `migrations.apply_duration_ms`) read them out of
+ * `testInMemoryMetricExporter`.
+ *
+ * Node ≥18 exposes `crypto.subtle` globally, so no crypto polyfill is
+ * required. Server-tier: `node:fs/promises` is available natively.
+ */
+import { metrics } from "@opentelemetry/api";
+import {
+    AggregationTemporality,
+    InMemoryMetricExporter,
+    MeterProvider,
+    PeriodicExportingMetricReader,
+} from "@opentelemetry/sdk-metrics";
+
+export const testInMemoryMetricExporter = new InMemoryMetricExporter(
+    AggregationTemporality.CUMULATIVE
+);
+
+const reader = new PeriodicExportingMetricReader({
+    exporter: testInMemoryMetricExporter,
+    exportIntervalMillis: 60_000,
+});
+
+export const testMeterProvider = new MeterProvider({ readers: [reader] });
+metrics.setGlobalMeterProvider(testMeterProvider);
+
+export async function flushTestMetrics() {
+    await testMeterProvider.forceFlush();
+    const collected = testInMemoryMetricExporter.getMetrics();
+    testInMemoryMetricExporter.reset();
+    return collected;
+}