Update changelog when performing a release. (#8)

* Update changelog when performing a release.

* Use conventions from Keep a Changelog: https://keepachangelog.com/en/1.0.0/

* Bugfix PR title.

* Switch back to main after a release PR.

* Clarify that release levels are applyed after the release.

Author: razvan

release/README.md

@@ -22,19 +22,21 @@ Optionally, if you want to have a GitHub Pull-Request automatically created, you
 
 Go to the folder containing a Cargo workspace or crate and run:
 
-    release.sh [major|minor|patch] [false]
+    release.sh [<next-devel-level>] [false]
+
+where `next-devel-level` is the version level to be increased *after* the release is done. This ca be `major`, `minor` or `patch`.
 
 This pushes two commits in a newly created release branch. When merging, __do not squash them__.
 
 Examples:
 
-    # Perform release raise the minor version
+    # Perform release and raise the minor version afterwards
     $ release.sh
 
     # Perform a release but do not push anything to origin
     $ release.sh minor false
 
-    # Perform a release and raise the major version
+    # Perform a release and raise the major version for the next development version
     $ release.sh major
 
 ## Description

release/release.sh

@@ -29,6 +29,14 @@ maybe_create_github_pr() {
   fi
 }
 
+update_changelog() {
+  local RELEASE_VERSION=$1;
+
+  TODAY=$(date +'%Y-%m-%d')
+
+  sed -i "s/^.*unreleased.*/## [Unreleased]\n\n## [$RELEASE_VERSION] - $TODAY\n/I" CHANGELOG.md
+}
+
 main() {
 
   local NEXT_LEVEL=${1:-minor}
@@ -41,22 +49,27 @@ main() {
   #
   cargo-version.py --release
   cargo update --workspace
-  local TAG=$(cargo-version.py --show)
-  git commit -am "bump version $TAG"
-  git tag -a $TAG -m "release $TAG" HEAD
+  local RELEASE_VERSION=$(cargo-version.py --show)
+
+  update_changelog $RELEASE_VERSION
+
+  git commit -am "bump version $RELEASE_VERSION"
+  git tag -a $RELEASE_VERSION -m "release $RELEASE_VERSION" HEAD
 
   #
   # Development
   #
   cargo-version.py --next ${NEXT_LEVEL}
   cargo update --workspace
   local NEXT_TAG=$(cargo-version.py --show)
+
   git commit -am "bump version $NEXT_TAG"
 
   if [ "$PUSH" = "true" ]; then
     git push ${REPOSITORY} ${RELEASE_BRANCH} 
     git push --tags
-    maybe_create_github_pr $TAG
+    maybe_create_github_pr $RELEASE_VERSION
+    git switch main
   fi
 }