From 323160dd385199ce39629583e771b1356bb525bb Mon Sep 17 00:00:00 2001
From: Paul-Henry Kajfasz <42912740+phklive@users.noreply.github.com>
Date: Thu, 18 Jul 2024 19:53:47 +0200
Subject: [PATCH] chore: add `changelog.yml` file (#1406)

---
 .github/workflows/changelog.yml | 23 +++++++++++++++++++++++
 .github/workflows/lint.yml      | 20 --------------------
 CHANGELOG.md                    |  3 ++-
 scripts/check-changelog.sh      | 21 +++++++++++++++++++++
 4 files changed, 46 insertions(+), 21 deletions(-)
 create mode 100644 .github/workflows/changelog.yml
 create mode 100755 scripts/check-changelog.sh

diff --git a/.github/workflows/changelog.yml b/.github/workflows/changelog.yml
new file mode 100644
index 0000000000..5fde0d8d0f
--- /dev/null
+++ b/.github/workflows/changelog.yml
@@ -0,0 +1,23 @@
+# Runs changelog related jobs.
+# CI job heavily inspired by: https://github.com/tarides/changelog-check-action
+
+name: changelog
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize]
+
+jobs:
+  changelog:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@main
+        with:
+          fetch-depth: 0
+      - name: Check for changes in changelog
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.ref }}
+          NO_CHANGELOG_LABEL: ${{ contains(github.event.pull_request.labels.*.name, 'no changelog') }}
+        run: ./scripts/check-changelog.sh "${{ inputs.changelog }}"
+        shell: bash
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 7c5d443946..b06425c54e 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -51,23 +51,3 @@ jobs:
           override: true
       - name: check rust versions
         run: ./scripts/check-rust-version.sh
-
-  changelog:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@main
-        with:
-          fetch-depth: 0
-      - name: Check if CHANGELOG.md is modified
-        run: |
-          # Get the list of changed files in the PR
-          changed_files=$(git diff --name-only origin/${{ github.event.pull_request.base.ref }}...${{ github.sha }})
-
-          # Check if CHANGELOG.md is in the list of changed files
-          if echo "$changed_files" | grep -q '^CHANGELOG.md$'; then
-            echo "CHANGELOG.md has been modified."
-          else
-            echo $'::warning file=CHANGELOG.md::CHANGELOG.md has not been modified.\n This warning can be ignored if is has been explicitely decided not to log changes.\n Except in this situation, make sure to add log changes.'
-            exit 1
-          fi
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 89c5cd9821..a33b178741 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,6 @@
 
 #### Enhancements
 
-- Updated CI and Makefile to standardise it accross Miden repositories (#1342).
 - Added error codes support for the `mtree_verify` instruction (#1328).
 - Added support for immediate values for `lt`, `lte`, `gt`, `gte` comparison instructions (#1346).
 - Change MAST to a table-based representation (#1349)
@@ -16,7 +15,9 @@
 - Relaxed the parser to allow one branch of an `if.(true|false)` to be empty
 - Added support for immediate values for `u32and`, `u32or`, `u32xor` and `u32not` bitwise instructions (#1362).
 - Optimized `std::sys::truncate_stuck` procedure (#1384).
+- Updated CI and Makefile to standardise it accross Miden repositories (#1342).
 - Add serialization/deserialization for `MastForest` (#1370)
+- Updated CI to support `CHANGELOG.md` modification checking and `no changelog` label (#1406)
 
 #### Changed
 
diff --git a/scripts/check-changelog.sh b/scripts/check-changelog.sh
new file mode 100755
index 0000000000..dbf14cdbb0
--- /dev/null
+++ b/scripts/check-changelog.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+set -uo pipefail
+
+CHANGELOG_FILE="${1:-CHANGELOG.md}"
+
+if [ "${NO_CHANGELOG_LABEL}" = "true" ]; then
+    # 'no changelog' set, so finish successfully
+    echo "\"no changelog\" label has been set"
+    exit 0
+else
+    # a changelog check is required
+    # fail if the diff is empty
+    if git diff --exit-code "origin/${BASE_REF}" -- "${CHANGELOG_FILE}"; then
+        >&2 echo "Changes should come with an entry in the \"CHANGELOG.md\" file. This behavior
+can be overridden by using the \"no changelog\" label, which is used for changes
+that are trivial / explicitely stated not to require a changelog entry."
+        exit 1
+    fi
+
+    echo "The \"CHANGELOG.md\" file has been updated."
+fi