ci: ensure Cargo.toml and CHANGELOG of published crates are updated

.github/workflows/ci.yml

@@ -33,6 +33,8 @@ jobs:
       CRATE: ${{ matrix.crate }}
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - uses: r7kamura/rust-problem-matchers@2c2f1016021a7455a6b5b4bbae31145f3b3cd83a #v1.4.0
 
@@ -70,6 +72,15 @@ jobs:
 
           test "$PACKAGE_VERSION" = "$SPECIFIED_VERSION"
 
+      - name: Ensure manifest and CHANGELOG are properly updated
+        if: github.event_name == 'pull_request'
+        run: |
+          git fetch origin master:master
+          ./scripts/ensure-version-bump-and-changelog.sh
+        env:
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+
+
   wasm_tests:
     name: Run all WASM tests
     runs-on: ubuntu-latest

scripts/ensure-version-bump-and-changelog.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+set -ex;
+
+MANIFEST_PATH=$(cargo metadata --format-version=1 --no-deps | jq -e -r '.packages[] | select(.name == "'"$CRATE"'") | .manifest_path')
+DIR_TO_CRATE=$(dirname "$MANIFEST_PATH")
+
+MERGE_BASE=$(git merge-base "$HEAD_SHA" master) # Find the merge base. This ensures we only diff what was actually added in the PR.
+
+DIFF_TO_MASTER=$(git diff "$HEAD_SHA".."$MERGE_BASE" --name-status -- "$DIR_TO_CRATE")
+CHANGELOG_DIFF=$(git diff "$HEAD_SHA".."$MERGE_BASE" --name-only -- "$DIR_TO_CRATE/CHANGELOG.md")
+
+VERSION_IN_CHANGELOG=$(awk -F' ' '/^## [0-9]+\.[0-9]+\.[0-9]+/{print $2; exit}' "$DIR_TO_CRATE/CHANGELOG.md")
+VERSION_IN_MANIFEST=$(cargo metadata --format-version=1 --no-deps | jq -e -r '.packages[] | select(.name == "'"$CRATE"'") | .version')
+
+# First, ensure version in Cargo.toml and CHANGELOG are in sync. This should always hold, regardless of whether the code in the crate was modified.
+if [[ "$VERSION_IN_CHANGELOG" != "$VERSION_IN_MANIFEST" ]]; then
+    echo "Version in Cargo.toml ($VERSION_IN_MANIFEST) does not match version in CHANGELOG ($VERSION_IN_CHANGELOG)"
+    exit 1
+fi
+
+# If the crate wasn't touched in this PR, exit early.
+if [ -z "$DIFF_TO_MASTER" ]; then
+  exit 0;
+fi
+
+# Code was touched, ensure changelog is updated too.
+if [ -z "$CHANGELOG_DIFF" ]; then
+    echo "Files in $DIR_TO_CRATE have changed, please write a changelog entry in $DIR_TO_CRATE/CHANGELOG.md"
+    exit 1
+fi
+
+# Code was touched, ensure the version used in the manifest hasn't been released yet.
+if git tag | grep -q "^$CRATE-v${VERSION_IN_MANIFEST}$"; then
+    echo "v$VERSION_IN_MANIFEST of '$CRATE' has already been released, please bump the version."
+    exit 1
+fi