Add cross-platform release pipeline

Author: forhappy

.github/workflows/publish-homebrew.yml

@@ -0,0 +1,58 @@
+name: Publish Homebrew Formula
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Stable Trail release tag to publish"
+        required: true
+        type: string
+
+permissions:
+  contents: read
+
+jobs:
+  publish:
+    if: ${{ github.event_name == 'workflow_dispatch' || !github.event.release.prerelease }}
+    runs-on: ubuntu-latest
+    env:
+      RELEASE_TAG: ${{ github.event_name == 'workflow_dispatch' && inputs.tag || github.event.release.tag_name }}
+      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - name: Download formula from the GitHub Release
+        run: |
+          mkdir -p "${RUNNER_TEMP}/formula"
+          gh release download "${RELEASE_TAG}" \
+            --repo "${GITHUB_REPOSITORY}" \
+            --pattern trail.rb \
+            --dir "${RUNNER_TEMP}/formula"
+          ruby -c "${RUNNER_TEMP}/formula/trail.rb"
+      - name: Check out the Crab Build tap
+        uses: actions/checkout@v6
+        with:
+          repository: crabbuild/homebrew-tap
+          token: ${{ secrets.HOMEBREW_TAP_TOKEN }}
+          path: homebrew-tap
+      - name: Commit and push the formula
+        run: |
+          mkdir -p homebrew-tap/Formula
+          install -m 0644 "${RUNNER_TEMP}/formula/trail.rb" homebrew-tap/Formula/trail.rb
+          cd homebrew-tap
+          unexpected="$(git status --porcelain | awk '$2 != "Formula/trail.rb"')"
+          if [[ -n "${unexpected}" ]]; then
+            echo "Refusing to publish because unrelated tap files changed:"
+            echo "${unexpected}"
+            exit 1
+          fi
+          if git diff --quiet -- Formula/trail.rb && \
+             git ls-files --error-unmatch Formula/trail.rb >/dev/null 2>&1; then
+            echo "Formula/trail.rb is already current"
+            exit 0
+          fi
+          git config user.name "Crab Build Release Bot"
+          git config user.email "[email protected]"
+          git add Formula/trail.rb
+          git commit -m "trail ${RELEASE_TAG#v}"
+          git push

.github/workflows/release-readiness.yml

@@ -0,0 +1,69 @@
+name: Release Readiness
+
+on:
+  pull_request:
+    paths:
+      - "Cargo.toml"
+      - "Cargo.lock"
+      - "trail/Cargo.toml"
+      - "trail/src/cli/command.rs"
+      - "CHANGELOG.md"
+      - "RELEASING.md"
+      - ".github/workflows/release.yml"
+      - ".github/workflows/publish-homebrew.yml"
+      - ".github/workflows/release-readiness.yml"
+  workflow_dispatch:
+
+jobs:
+  package-smoke:
+    name: Package smoke (${{ matrix.os }})
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          submodules: recursive
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: Build release binary
+        run: cargo build --locked -p trail --profile dist
+      - name: Verify packaged CLI
+        shell: bash
+        run: |
+          set -euo pipefail
+          suffix=""
+          if [[ "${RUNNER_OS}" == "Windows" ]]; then
+            suffix=".exe"
+          fi
+          binary="${PWD}/target/dist/trail${suffix}"
+          expected="$(sed -n '/^\[workspace.package\]/,/^\[/s/^version = "\([^"]*\)"/\1/p' Cargo.toml)"
+          actual="$("${binary}" --version)"
+          test "${actual}" = "trail ${expected}"
+          "${binary}" --help >/dev/null
+
+          smoke_dir="$(mktemp -d)"
+          trap 'rm -rf "${smoke_dir}"' EXIT
+          cd "${smoke_dir}"
+          printf 'release smoke test\n' > README.md
+          "${binary}" init --working-tree
+          "${binary}" status
+
+  dist-plan:
+    name: Generated release workflow is current
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          submodules: recursive
+      - name: Install pinned dist
+        shell: bash
+        run: |
+          curl --proto '=https' --tlsv1.2 -LsSf \
+            https://github.com/axodotdev/cargo-dist/releases/download/v0.32.0/cargo-dist-installer.sh | sh
+      - name: Check release configuration
+        run: |
+          dist generate --mode=ci --check
+          dist plan --tag="v$(sed -n '/^\[workspace.package\]/,/^\[/s/^version = "\([^"]*\)"/\1/p' Cargo.toml)"