chore(ci): bump alpha release for breaking changes (#495)

Automatically detect breaking changes based on commit messages
and bump the alpha release number accordingly.

E.g. v0.23.1-alpha.1 will be bumped to v0.24.0-alpha.0 if any commit
since v0.23.0 has a breaking change.

.github/workflows/calculate-alpha-release.bash

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+# Exit on error. Append "|| true" if you expect an error.
+set -o errexit
+# Exit on error inside any functions or subshells.
+set -o errtrace
+# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
+set -o nounset
+# Catch the error in case mysqldump fails (but gzip succeeds) in `mysqldump |gzip`
+set -o pipefail
+# Turn on traces, useful while debugging but commented out by default
+# set -o xtrace
+
+last_release="$(git tag --sort=committerdate | grep -E "v0\.\d+\.\d+$" | tail -1)"
+echo "🐭 Last release: ${last_release}"
+
+# detect breaking changes
+if git log --oneline ${last_release}..HEAD | grep -q '!:' || true; then
+    echo "🐭 Breaking changes detected since ${last_release}"
+    git log --oneline ${last_release}..HEAD | grep '!:'
+    # increment the minor version
+    minor="${last_release##v0.}"
+    minor="${minor%.*}"
+    next_minor="$((minor + 1))"
+    next_release="v0.${next_minor}.0"
+else
+    # increment the patch version
+    patch="${last_release##*.}"
+    next_patch="$((patch + 1))"
+    next_release="${last_release/%${patch}/${next_patch}}"
+fi
+echo "🐭 Next release: ${next_release}"
+
+suffix="alpha"
+last_tag="$(git tag --sort=committerdate | tail -1)"
+if [[ "${last_tag}" = "${next-release}-${suffix}"* ]]; then
+    echo "🐭 Last alpha release: ${last_tag}"
+    # increment the alpha version
+    # e.g. v0.22.1-alpha.12 -> v0.22.1-alpha.13
+    alpha="${last_tag##*-${suffix}.}"
+    next_alpha="$((alpha + 1))"
+    next_tag="${last_tag/%${alpha}/${next_alpha}}"
+else
+    # increment the patch and start the alpha version from 0
+    # e.g. v0.22.0 -> v0.22.1-alpha.0
+    next_tag="${next_release}-${suffix}.0"
+fi
+# update the crate version
+msg="# crate version"
+sed -E -i "s/^version = .* ${msg}$/version = \"${next_tag#v}\" ${msg}/" Cargo.toml
+echo "NEXT_TAG=${next_tag}" >> $GITHUB_ENV
+echo "🐭 Next alpha release: ${next_tag}"

.github/workflows/cd.yml

@@ -28,27 +28,7 @@ jobs:
           fetch-depth: 0
 
       - name: Calculate the next release
-        run: |
-          suffix="alpha"
-          last_tag="$(git tag --sort=committerdate | tail -1)"
-          if [[ "${last_tag}" = *"-${suffix}"* ]]; then
-            # increment the alpha version
-            # e.g. v0.22.1-alpha.12 -> v0.22.1-alpha.13
-            alpha="${last_tag##*-${suffix}.}"
-            next_alpha="$((alpha + 1))"
-            next_tag="${last_tag/%${alpha}/${next_alpha}}"
-          else
-            # increment the patch and start the alpha version from 0
-            # e.g. v0.22.0 -> v0.22.1-alpha.0
-            patch="${last_tag##*.}"
-            next_patch="$((patch + 1))"
-            next_tag="${last_tag/%${patch}/${next_patch}}-${suffix}.0"
-          fi
-          # update the crate version
-          msg="# crate version"
-          sed -E -i "s/^version = .* ${msg}$/version = \"${next_tag#v}\" ${msg}/" Cargo.toml
-          echo "NEXT_TAG=${next_tag}" >> $GITHUB_ENV
-          echo "Next alpha release: ${next_tag} 🐭"
+        run: .github/workflows/calculate-alpha-release.bash
 
       - name: Publish on crates.io
         uses: actions-rs/cargo@v1