fix(ci): skip the heavy job fan-out for draft pull requests

.github/workflows/ci.yml

@@ -2,6 +2,10 @@ name: CI
 
 on:
   pull_request:
+    # Explicit list because the default (opened/synchronize/reopened) omits ready_for_review -- once the
+    # heavy jobs below start skipping draft PRs, marking a PR ready must itself trigger a real CI run, not
+    # wait for the next push.
+    types: [opened, synchronize, reopened, ready_for_review]
   push:
     branches:
       - main
@@ -165,7 +169,9 @@ jobs:
   validate-code:
     name: validate-code
     needs: changes
-    if: ${{ github.event_name == 'push' || needs.changes.outputs.backend == 'true' || needs.changes.outputs.mcp == 'true' || needs.changes.outputs.engine == 'true' || needs.changes.outputs.miner == 'true' || needs.changes.outputs.rees == 'true' || needs.changes.outputs.ui == 'true' || needs.changes.outputs.observability == 'true' }}
+    # draft != true also gates push runs correctly: github.event.pull_request is unset there, so the
+    # property access evaluates to null, and null != true is true.
+    if: ${{ github.event_name == 'push' || (github.event.pull_request.draft != true && (needs.changes.outputs.backend == 'true' || needs.changes.outputs.mcp == 'true' || needs.changes.outputs.engine == 'true' || needs.changes.outputs.miner == 'true' || needs.changes.outputs.rees == 'true' || needs.changes.outputs.ui == 'true' || needs.changes.outputs.observability == 'true')) }}
     runs-on: ubuntu-latest
     timeout-minutes: 45
     env:
@@ -446,7 +452,7 @@ jobs:
   validate-tests:
     name: validate-tests
     needs: changes
-    if: ${{ github.event_name == 'push' || needs.changes.outputs.backend == 'true' }}
+    if: ${{ github.event_name == 'push' || (github.event.pull_request.draft != true && needs.changes.outputs.backend == 'true') }}
     runs-on: ubuntu-latest
     timeout-minutes: 20
     strategy:
@@ -627,7 +633,7 @@ jobs:
   validate-tests-merge:
     name: validate-tests-merge
     needs: [changes, validate-tests]
-    if: ${{ github.event_name == 'push' || needs.changes.outputs.backend == 'true' }}
+    if: ${{ github.event_name == 'push' || (github.event.pull_request.draft != true && needs.changes.outputs.backend == 'true') }}
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
@@ -678,7 +684,7 @@ jobs:
   # audit workflow, so one upstream CVE never blocks unrelated PRs.
   security:
     name: security
-    if: ${{ github.event_name == 'pull_request' }}
+    if: ${{ github.event_name == 'pull_request' && github.event.pull_request.draft != true }}
     # actions/dependency-review-action needs no self-hosted toolchain/cache (checkout + a lockfile diff), so
     # this always runs on ubuntu-latest -- keeping it self-hosted for same-repo PRs only competed for the
     # scarce self-hosted pool with validate-code, the one job that actually benefits from it (#2501).

test/unit/ci-skip-draft-prs.test.ts

@@ -0,0 +1,53 @@
+import { readFileSync } from "node:fs";
+import { parse } from "yaml";
+import { describe, expect, it } from "vitest";
+
+function readYaml(path: string): Record<string, unknown> {
+  return record(parse(readFileSync(path, "utf8")), path);
+}
+
+function record(value: unknown, label: string): Record<string, unknown> {
+  if (!value || typeof value !== "object" || Array.isArray(value)) {
+    throw new Error(`${label} must be an object`);
+  }
+  return value as Record<string, unknown>;
+}
+
+// Regression guard: draft PRs were consuming the exact same 11-job GitHub-hosted-runner fan-out as ready
+// PRs (validate-code, the 6-way validate-tests shard matrix, validate-tests-merge, security), which both
+// (a) let contributors farm bot labels/AI review/screenshots for free while sitting in draft, and (b)
+// materially worsened the account's shared-runner queue contention for every other PR in flight. The heavy
+// jobs now require the PR not be a draft; the cheap `changes` and `validate` (result-aggregation) jobs still
+// run unconditionally since `validate` already treats a skipped dependency as success.
+describe("ci.yml skips the heavy jobs for draft pull requests", () => {
+  const workflow = readYaml(".github/workflows/ci.yml");
+  const jobs = record(workflow.jobs, "workflow.jobs");
+
+  it("pull_request trigger explicitly includes ready_for_review (the default type list omits it)", () => {
+    const on = record(workflow.on, "workflow.on");
+    const pullRequest = record(on.pull_request, "workflow.on.pull_request");
+    expect(pullRequest.types).toEqual(["opened", "synchronize", "reopened", "ready_for_review"]);
+  });
+
+  it.each(["validate-code", "validate-tests", "validate-tests-merge"])(
+    "%s's if-condition requires github.event.pull_request.draft != true alongside the existing push/path-filter checks",
+    (jobName) => {
+      const job = record(jobs[jobName], `jobs.${jobName}`);
+      const condition = String(job.if);
+      expect(condition).toContain("github.event.pull_request.draft != true");
+      // Push runs (no PR context at all) must still be unaffected -- github.event_name == 'push' short-circuits first.
+      expect(condition).toContain("github.event_name == 'push'");
+    },
+  );
+
+  it("security's if-condition requires github.event.pull_request.draft != true", () => {
+    const job = record(jobs.security, "jobs.security");
+    expect(String(job.if)).toBe("${{ github.event_name == 'pull_request' && github.event.pull_request.draft != true }}");
+  });
+
+  it("validate still aggregates all four gated jobs and treats a skipped dependency as success", () => {
+    const job = record(jobs.validate, "jobs.validate");
+    expect(job.needs).toEqual(["changes", "validate-code", "validate-tests", "validate-tests-merge", "security"]);
+    expect(String(job.if)).toBe("${{ always() }}");
+  });
+});