sim/.github/workflows/codeql.yml

name: codeql

# Advanced setup, replacing the repo-settings "default setup".
#
# Default setup pinned every scan to a 4-vCPU GitHub-hosted runner with no
# cancel-in-progress, which put PR scans at 30-125 min and re-ran them on every
# push (PR #6183 burned six overlapping runs). None of that is configurable from
# the settings UI, so the config moves into the repo.
#
# Before enabling this, disable default setup or the two will both run:
#   gh api -X PATCH repos/:owner/:repo/code-scanning/default-setup -f state=not-configured
#
# The runs-on expression is the same CI_PROVIDER escape hatch as ci.yml and must
# change together with it.

on:
  # Pushes to main are infrequent (merges only), so a full scan per push is
  # affordable and is what GitHub recommends pairing with the PR trigger:
  # "Scanning code when someone pushes a change, and whenever a pull request is
  # created, prevents developers from introducing new vulnerabilities."
  push:
    branches: [main]
  # main only, not staging. Feature PRs land on staging and are ~90% of PR scan
  # volume, and every one of them is scanned again — against the exact tree being
  # promoted — when the staging->main PR opens. Scanning at the promotion
  # boundary defers the signal rather than dropping it.
  #
  # Deliberately a branch cut and not an activity-type cut: dropping
  # `synchronize` would have scanned each PR's first commit and never its final
  # state, which is backwards, since review fixups land in later pushes.
  pull_request:
    branches: [main]
    # `ready_for_review` is not a default activity type, so it has to be listed
    # alongside the defaults it replaces. Without it, a PR opened as a draft and
    # then marked ready is skipped by the job-level draft guard and never
    # rescanned until the next push.
    types: [opened, synchronize, reopened, ready_for_review]
    paths:
      - '**/*.ts'
      - '**/*.tsx'
      - '**/*.js'
      - '**/*.jsx'
      - '**/*.mjs'
      - '**/*.cjs'
      - '.github/workflows/**'
      - '.github/actions/**'
      - '.github/codeql/**'
  schedule:
    # Safety net behind the push trigger, and the thing that keeps the
    # default-branch alert view fresh when main is quiet. Only fires once this
    # file is on the default branch — schedule events ignore other branches.
    #
    # Daily rather than weekly. Pushes to main are rare, and with PR scans now
    # limited to main the alert view leans on this more than it used to; a week
    # is too long to leave it stale. It also reseeds the overlay-base database
    # that PR runs restore from — that cache key embeds the CodeQL bundle
    # version, so a bundle bump invalidates it, and an unused Actions cache is
    # evicted after 7 days. One 8 vCPU default-branch scan a day is a few
    # dollars a month against a PR scan that halves when the base is warm.
    - cron: '17 8 * * *'
  workflow_dispatch:

concurrency:
  group: codeql-${{ github.ref }}
  # PR runs only. Superseding is what this is for: a PR push makes the previous
  # scan of that PR irrelevant, and `refs/pull/N/merge` keeps each PR in its own
  # group. The push and schedule triggers both resolve to `refs/heads/main`, so a
  # blanket `true` let the daily cron cancel the merge scan of the same commit --
  # a 2-minute window that finally landed on 3c8a4c4 (push 08:32:58 killed by the
  # 08:34:47 cron), leaving main with a red rollup for a commit that the cron had
  # in fact scanned clean. Non-PR events now queue instead: one pending run is
  # held per group, so the cron simply waits out the merge scan.
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

permissions:
  contents: read

jobs:
  analyze:
    name: analyze (${{ matrix.language }})
    # Sized per language, not per workflow. The two analyses are nothing alike:
    # javascript-typescript peaks at 19.5 GB (p95 over 3090 runs), so it needs
    # the 8 vCPU tier's 30.4 GB and would OOM on the 4 vCPU tier's 15.2 GB; the
    # actions analysis peaks at 1.3 GB and averages 22% CPU over a 39s median
    # run, so 8 vCPU was 4x more machine than it ever used.
    runs-on: ${{ (vars.CI_PROVIDER == '' || vars.CI_PROVIDER == 'blacksmith') && matrix.bs_runner || 'ubuntu-latest' }}
    timeout-minutes: 60
    if: github.event.pull_request.draft != true
    permissions:
      security-events: write
      contents: read
      actions: read

    strategy:
      fail-fast: false
      matrix:
        # One entry covers both JS and TS — `javascript`, `typescript` and
        # `javascript-typescript` all resolve to the same extractor
        # (github/codeql-action src/languages/builtin.json), so the three
        # entries default setup listed were one analysis, not three.
        # `javascript-typescript` is the documented spelling. Python dropped:
        # 7 files in the tree.
        include:
          - language: javascript-typescript
            bs_runner: blacksmith-8vcpu-ubuntu-2404
          - language: actions
            bs_runner: blacksmith-4vcpu-ubuntu-2404

    steps:
      - name: Checkout repository
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v6
        with:
          persist-credentials: false

      - name: Initialize CodeQL
        uses: github/codeql-action/init@18420e3271f74589575af831a523c833acda327f # codeql-bundle-v2.26.2
        with:
          languages: ${{ matrix.language }}
          config-file: ./.github/codeql/codeql-config.yml

      - name: Perform CodeQL Analysis
        uses: github/codeql-action/analyze@18420e3271f74589575af831a523c833acda327f # codeql-bundle-v2.26.2
        env:
          NODE_OPTIONS: --max-old-space-size=8192
        with:
          category: /language:${{ matrix.language }}