From c02e6a795419e1b08aa441a145c26e2900cb7d63 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20M=C3=BCller?= <straightshoota@gmail.com>
Date: Sat, 13 Jan 2024 21:30:09 +0100
Subject: [PATCH 1/4] Add `scripts/update-changelog.sh`

---
 scripts/update-changelog.sh | 66 +++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100755 scripts/update-changelog.sh

diff --git a/scripts/update-changelog.sh b/scripts/update-changelog.sh
new file mode 100755
index 000000000000..f4ff09a9dbef
--- /dev/null
+++ b/scripts/update-changelog.sh
@@ -0,0 +1,66 @@
+#! /bin/sh
+
+# This script automates generating changelog with `scripts/github-changelog.cr`,
+# editing it into `CHANGELOG.md` and pushing it to a `changelog/$VERSION` branch.
+#
+# It reads the current (dev-)version from `src/VERSION` and generates the
+# changelog entries for all PRs from the respective GitHub milestone via
+# `scripts/github-changelog.cr`.
+# The section is then inserted into `CHANGELOG.md`, overwriting any previous
+# content for this milestone.
+# Finally, the changes are commited and pushed to `changelog/$VERSION`.
+# If the changelog section is *new*, also creates a draft PR for this branch.
+#
+# Usage:
+#
+#   scripts/update-changelog.sh
+#
+# Requirements:
+#
+#   - scripts/github-changelog.cr
+#   - git
+#   - grep
+#   - sed
+#
+# Environment variables:
+#   GITHUB_TOKEN: Access token for the GitHub API (required)
+
+set -eu
+
+VERSION=${1:-$(cat src/VERSION)}
+VERSION=${VERSION%-dev}
+
+base_branch=$(git rev-parse --abbrev-ref HEAD)
+branch="changelog/$VERSION"
+current_changelog="CHANGELOG.$VERSION.md"
+
+echo "Switching to branch $branch"
+git switch $branch 2>/dev/null || git switch -c $branch;
+
+echo "Generating $current_changelog..."
+
+scripts/github-changelog.cr $VERSION > $current_changelog
+
+if grep -E "^## \[$VERSION\]" CHANGELOG.md; then
+  echo "Replacing section in CHANGELOG"
+
+  sed -iE "/^## \[$VERSION\]/,/^## /{
+    /^## \[$VERSION\]/s/.*/cat $current_changelog/e; /^## /!d
+  }" CHANGELOG.md
+
+  git add CHANGELOG.md
+  git commit -m "Update changelog for $VERSION"
+  git push
+else
+  echo "Adding new section to CHANGELOG"
+
+  sed -iE "2r $current_changelog" CHANGELOG.md
+
+  git add CHANGELOG.md
+  git commit -m "Add changelog for $VERSION"
+  git push -u upstream $branch
+
+  gh pr create --draft --base "$base_branch" \
+    --body "Preview: https://github.com/crystal-lang/crystal/blob/$branch/CHANGELOG.md" \
+    --label "topic:infrastructure" -t "Changelog for $VERSION" --milestone "$VERSION"
+fi

From a206e9f9533846631cb8302b499285e831f8cb29 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20M=C3=BCller?= <straightshoota@gmail.com>
Date: Mon, 26 Feb 2024 10:45:31 +0100
Subject: [PATCH 2/4] Use script from current branch to generate changelog

---
 scripts/update-changelog.sh | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/scripts/update-changelog.sh b/scripts/update-changelog.sh
index f4ff09a9dbef..d691ccf00b35 100755
--- a/scripts/update-changelog.sh
+++ b/scripts/update-changelog.sh
@@ -34,13 +34,12 @@ base_branch=$(git rev-parse --abbrev-ref HEAD)
 branch="changelog/$VERSION"
 current_changelog="CHANGELOG.$VERSION.md"
 
-echo "Switching to branch $branch"
-git switch $branch 2>/dev/null || git switch -c $branch;
-
 echo "Generating $current_changelog..."
-
 scripts/github-changelog.cr $VERSION > $current_changelog
 
+echo "Switching to branch $branch"
+git switch $branch 2>/dev/null || git switch -c $branch;
+
 if grep -E "^## \[$VERSION\]" CHANGELOG.md; then
   echo "Replacing section in CHANGELOG"
 

From 45d0afcc4a1b3ad5b452d74bd6fa31a8c03638b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20M=C3=BCller?= <straightshoota@gmail.com>
Date: Wed, 3 Apr 2024 13:10:10 +0200
Subject: [PATCH 3/4] Add `--silent`

---
 scripts/update-changelog.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/update-changelog.sh b/scripts/update-changelog.sh
index d691ccf00b35..61edf660db74 100755
--- a/scripts/update-changelog.sh
+++ b/scripts/update-changelog.sh
@@ -40,7 +40,7 @@ scripts/github-changelog.cr $VERSION > $current_changelog
 echo "Switching to branch $branch"
 git switch $branch 2>/dev/null || git switch -c $branch;
 
-if grep -E "^## \[$VERSION\]" CHANGELOG.md; then
+if grep --silent -E "^## \[$VERSION\]" CHANGELOG.md; then
   echo "Replacing section in CHANGELOG"
 
   sed -iE "/^## \[$VERSION\]/,/^## /{

From 541ede8ed7571debd039298a5c091750ef7b50a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20M=C3=BCller?= <straightshoota@gmail.com>
Date: Wed, 3 Apr 2024 13:14:47 +0200
Subject: [PATCH 4/4] Fix sed flags

---
 scripts/update-changelog.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/update-changelog.sh b/scripts/update-changelog.sh
index 61edf660db74..777f65a60e3d 100755
--- a/scripts/update-changelog.sh
+++ b/scripts/update-changelog.sh
@@ -43,7 +43,7 @@ git switch $branch 2>/dev/null || git switch -c $branch;
 if grep --silent -E "^## \[$VERSION\]" CHANGELOG.md; then
   echo "Replacing section in CHANGELOG"
 
-  sed -iE "/^## \[$VERSION\]/,/^## /{
+  sed -i -E "/^## \[$VERSION\]/,/^## /{
     /^## \[$VERSION\]/s/.*/cat $current_changelog/e; /^## /!d
   }" CHANGELOG.md
 
@@ -53,7 +53,7 @@ if grep --silent -E "^## \[$VERSION\]" CHANGELOG.md; then
 else
   echo "Adding new section to CHANGELOG"
 
-  sed -iE "2r $current_changelog" CHANGELOG.md
+  sed -i -E "2r $current_changelog" CHANGELOG.md
 
   git add CHANGELOG.md
   git commit -m "Add changelog for $VERSION"