ci: checks if a crate needs a version bump

Author: weihanglo

.github/workflows/main.yml

@@ -43,6 +43,17 @@ jobs:
       - run: rustup update stable && rustup default stable
       - run: cargo stale-label
 
+  check-version-bump:
+    runs-on: ubuntu-latest
+    env:
+      BASE_REF : ${{ github.base_ref }}
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0 # make `git diff` work
+      - run: rustup update stable && rustup default stable
+      - run: ci/validate-version-bump.sh
+
   # Ensure Cargo.lock is up-to-date
   lockfile:
     runs-on: ubuntu-latest
@@ -213,6 +224,7 @@ jobs:
     name: bors build finished
     needs:
     - build_std
+    - check-version-bump
     - docs
     - lockfile
     - resolver
@@ -229,6 +241,7 @@ jobs:
     name: bors build finished
     needs:
     - build_std
+    - check-version-bump
     - docs
     - lockfile
     - resolver

ci/validate-version-bump.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+# This script checks if a crate needs a version bump.
+#
+# At the time of writing, it doesn't check what kind of bump is required.
+# In the future, we could take SemVer compatibliity into account, like
+# integrating `cargo-semver-checks` of else
+#
+# Inputs:
+#     BASE_REF    The base branch of the pull request wanting to merge into.
+
+set -euo pipefail
+
+# When `BASE_REF` is missing, we assume it is from bors merge commit,
+# so `HEAD~` should find the previous commit on master branch.
+rev="${BASE_REF:+origin/$BASE_REF}"
+rev="${rev:-HEAD~}"
+
+changed_crates=$(
+    git diff --name-only "$rev" -- crates/ credential/ benches/ \
+    | cut  -d'/' -f2 \
+    | sort -u
+)
+
+if  [ -z "$changed_crates" ]
+then
+    echo "No file changed in sub crates."
+    exit 0
+fi
+
+output=$(
+    echo "$changed_crates" \
+    | xargs printf -- '--package %s\n' \
+    | xargs cargo unpublished --check-version-bump
+)
+
+if  [ -z "$output" ]
+then
+    echo "No version bump needed for sub crates."
+    exit 0
+fi
+
+echo "$output"
+exit 1