feat: add plugin-backed canvases (#3111)

apps/web/scripts/vitest-worker-budget.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import { resolveMaxWorkers } from "./vitest-worker-budget";
+
+describe("resolveMaxWorkers", () => {
+  it("uses the twenty-percent local default when no override is set", () => {
+    expect(resolveMaxWorkers(undefined, false, false, 10)).toBe("20%");
+  });
+
+  it("caps an unsafe local percentage override", () => {
+    expect(resolveMaxWorkers("100%", false, false, 10)).toBe("20%");
+  });
+
+  it("caps an unsafe local numeric override to available capacity", () => {
+    expect(resolveMaxWorkers("10", false, false, 10)).toBe(2);
+  });
+
+  it("keeps a safe local percentage override", () => {
+    expect(resolveMaxWorkers("10%", false, false, 10)).toBe("10%");
+  });
+
+  it("falls back for an invalid zero-worker percentage", () => {
+    expect(resolveMaxWorkers("0%", false, false, 10)).toBe("20%");
+  });
+
+  it("requires an explicit opt-in for unsafe local capacity", () => {
+    expect(resolveMaxWorkers("100%", false, true, 10)).toBe("100%");
+    expect(resolveMaxWorkers("100%", true, false, 10)).toBe("100%");
+  });
+});

apps/web/scripts/vitest-worker-budget.ts

@@ -0,0 +1,41 @@
+import os from "node:os";
+
+const LOCAL_WORKER_PERCENT = 20;
+
+export function resolveMaxWorkers(
+  value: string | undefined,
+  isCI: boolean,
+  allowUnsafe: boolean,
+  availableParallelism = os.availableParallelism(),
+): string | number | undefined {
+  const normalized = value?.trim();
+  if (isCI || allowUnsafe) return parseConfiguredWorkers(normalized);
+  if (!normalized) return `${LOCAL_WORKER_PERCENT}%`;
+
+  const percentage = parsePercentage(normalized);
+  if (percentage !== null) {
+    return percentage <= LOCAL_WORKER_PERCENT ? normalized : `${LOCAL_WORKER_PERCENT}%`;
+  }
+
+  const requestedWorkers = Number(normalized);
+  if (Number.isInteger(requestedWorkers) && requestedWorkers > 0) {
+    return Math.min(requestedWorkers, localWorkerBudget(availableParallelism));
+  }
+  return `${LOCAL_WORKER_PERCENT}%`;
+}
+
+function parseConfiguredWorkers(value: string | undefined): string | number | undefined {
+  if (!value) return undefined;
+  if (/^[1-9]\d*%$/.test(value)) return value;
+  const workers = Number(value);
+  return Number.isInteger(workers) && workers > 0 ? workers : undefined;
+}
+
+function parsePercentage(value: string): number | null {
+  if (!/^[1-9]\d*%$/.test(value)) return null;
+  return Number(value.slice(0, -1));
+}
+
+function localWorkerBudget(availableParallelism: number): number {
+  return Math.max(1, Math.floor(availableParallelism * (LOCAL_WORKER_PERCENT / 100)));
+}