feat: enforce web vitals performance budgets

2026-07-25 21:26:51 +09:00
parent 9d40724ab2
commit b1625252d5
11 changed files with 624 additions and 1 deletions
@@ -0,0 +1,102 @@
+import { mkdir, readFile, writeFile } from "node:fs/promises";
+
+import {
+  evaluateFieldBudget,
+  percentile75,
+} from "../src/application/policies/performance-budgets.js";
+
+const inputPath =
+  process.env.FIELD_WEB_VITALS_INPUT ??
+  "config/performance/field-input.example.json";
+const input =
+  /** @type {{
+   *   releaseId: string,
+   *   samples: Array<{
+   *     timestamp: string,
+   *     consent: boolean,
+   *     releaseId: string,
+   *     routeId: string,
+   *     lcpMs: number,
+   *     cls: number,
+   *     inpMs: number
+   *   }>
+   * }} */ (JSON.parse(await readFile(inputPath, "utf8")));
+const configured =
+  /** @type {{
+   *   p75LcpMs: number,
+   *   p75Cls: number,
+   *   p75InpMs: number,
+   *   minimumEligibleSamples: number | null
+   * }} */ (
+    JSON.parse(await readFile("config/performance/budgets.json", "utf8")).field
+  );
+const minimumEligibleSamples = process.env.MIN_ELIGIBLE_SAMPLES
+  ? Number(process.env.MIN_ELIGIBLE_SAMPLES)
+  : configured.minimumEligibleSamples;
+const end = new Date();
+const start = new Date(end);
+start.setUTCDate(start.getUTCDate() - 28);
+const eligible = input.samples.filter((sample) => {
+  const timestamp = new Date(sample.timestamp);
+  return (
+    sample.consent === true &&
+    sample.releaseId === input.releaseId &&
+    timestamp >= start &&
+    timestamp <= end
+  );
+});
+const metrics = {
+  p75LcpMs: percentile75(eligible.map((sample) => sample.lcpMs)),
+  p75Cls: percentile75(eligible.map((sample) => sample.cls)),
+  p75InpMs: percentile75(eligible.map((sample) => sample.inpMs)),
+};
+const thresholds = { ...configured, minimumEligibleSamples };
+const result = evaluateFieldBudget(
+  { metrics, eligibleSamples: eligible.length },
+  thresholds,
+);
+const routeSamples = Object.fromEntries(
+  Object.entries(
+    eligible.reduce(
+      (counts, sample) => {
+        counts[sample.routeId] = (counts[sample.routeId] ?? 0) + 1;
+        return counts;
+      },
+      /** @type {Record<string, number>} */ ({}),
+    ),
+  ).sort(([left], [right]) => left.localeCompare(right)),
+);
+const report = {
+  schemaVersion: 1,
+  generatedAt: end.toISOString(),
+  window: { days: 28, start: start.toISOString(), end: end.toISOString() },
+  context: {
+    source: inputPath,
+    network: "production-real-user",
+    routeAggregation: "route-id-only",
+    releaseId: input.releaseId,
+  },
+  metrics,
+  thresholds,
+  eligibility: {
+    consentRequired: true,
+    eligibleSamples: eligible.length,
+    minimumEligibleSamples,
+    routeSamples,
+  },
+  status: result.status,
+  passed: result.passed,
+};
+
+await mkdir("artifacts/performance", { recursive: true });
+await writeFile(
+  "artifacts/performance/field-web-vitals.json",
+  `${JSON.stringify(report, null, 2)}\n`,
+);
+if (!result.passed) {
+  process.stderr.write(
+    `Field Web Vitals: ${result.status} (minimum eligible sample threshold and 28-day production data are required)\n`,
+  );
+  process.exit(1);
+}
+process.stdout.write("Field Web Vitals: PASS\n");