From ead7a61a78cddd8de622237808f49040b96a1b46 Mon Sep 17 00:00:00 2001
From: Ivan Dlugos <dlugos.ivan@gmail.com>
Date: Mon, 17 Oct 2022 20:59:59 +0200
Subject: [PATCH] feat(danger):  check that a changelog entry is not added to
 an already released section

---
 CHANGELOG.md         |  2 +-
 danger/dangerfile.js | 29 +++++++++++++++++++++--------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 85350e1..6a4ce21 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@
 ### Features
 
 - Updater - add `changelog-entry` option to disable adding a changelog entry ([#43](https://github.com/getsentry/github-workflows/pull/43))
-- Danger - check a changelog entry is not added to an already released section ([#44](https://github.com/getsentry/github-workflows/pull/44))
+- Danger - check that a changelog entry is not added to an already released section ([#44](https://github.com/getsentry/github-workflows/pull/44))
 
 ## 2.2.2
 
diff --git a/danger/dangerfile.js b/danger/dangerfile.js
index e25551b..844af91 100644
--- a/danger/dangerfile.js
+++ b/danger/dangerfile.js
@@ -79,19 +79,32 @@ async function checkChangelog() {
     changelogFile
   );
 
-  const hasChangelogEntry = RegExp(`#${danger.github.pr.number}\\b`).test(
+  const changelogMatch = RegExp(`^(.*)\n[^\n]+#${danger.github.pr.number}\\b`, 's').exec(
     changelogContents
   );
 
-  if (hasChangelogEntry) {
-    return;
+  // check if a changelog entry exists
+  if (!changelogMatch) {
+    return reportMissingChangelog(changelogFile);
   }
 
-  // Report missing changelog entry
-  fail(
-    "Please consider adding a changelog entry for the next release.",
-    changelogFile
-  );
+  // Check if the entry is added to an Unreleased section (or rather, check that it's not added to a released one)
+  const textBeforeEntry = changelogMatch[1]
+  const section = RegExp('^(## +v?[0-9.]+)([\-\n _]|$)', 'm').exec(textBeforeEntry)
+  if (section) {
+    const lineNr = 1 + textBeforeEntry.split(/\r\n|\r|\n/).length
+    fail(
+      `The changelog entry seems to be part of an already released section \`${section[1]}\`.
+      Consider moving the entry to the appropriate subsection of the \`## Unreleased\` section, please.`,
+      changelogFile,
+      lineNr
+    );
+  }
+}
+
+/// Report missing changelog entry
+function reportMissingChangelog(changelogFile) {
+  fail("Please consider adding a changelog entry for the next release.", changelogFile);
 
   const prTitleFormatted = danger.github.pr.title
     .split(": ")