Upload Semgrep CI findings to GitHub Advanced Security Dashboard

# Name of this GitHub Actions workflow.
name: Semgrep

on:
  # Scan changed files in PRs (diff-aware scanning):
  pull_request: {}
  # Scan on-demand through GitHub Actions interface:
  workflow_dispatch: {}
  # Scan mainline branches and report all findings:
  push:
    branches: ["master", "main"]
  # Schedule the CI job (this method uses cron syntax):
  schedule:
    - cron: '20 17 * * *' # Sets Semgrep to scan every day at 17:20 UTC.
    # It is recommended to change the schedule to a random time.

permissions:
  # This permission is required when uploading sarifs to any repository at GitHub
  security-events: write
  # These permissions are only required when uploading sarifs to private and internal repositories at GitHub
  contents: read
  actions: read

jobs:
  semgrep:
    # User definable name of this GitHub Actions job.
    name: semgrep/ci
    # If you are self-hosting, change the following `runs-on` value:
    runs-on: ubuntu-latest

    container:
      # A Docker image with Semgrep installed. Do not change this.
      image: semgrep/semgrep

    # Skip any PR created by dependabot to avoid permission issues:
    if: (github.actor != 'dependabot[bot]')

    steps:
      # Fetch project source with GitHub Actions Checkout. Use either v3 or v4.
      - uses: actions/checkout@v6
      # Run the "semgrep ci" command on the command line of the docker image.
      - run: semgrep ci --sarif > semgrep.sarif
        env:
          # Connect to Semgrep AppSec Platform through your SEMGREP_APP_TOKEN.
          # Generate a token from Semgrep AppSec Platform > Settings
          # and add it to your GitHub secrets.
          SEMGREP_APP_TOKEN: ${{ secrets.SEMGREP_APP_TOKEN }}

      - name: Upload SARIF file for GitHub Advanced Security Dashboard
        uses: github/codeql-action/upload-sarif@v3
        with:
          sarif_file: semgrep.sarif
        if: always()