From 3165a5b504b35286e9e6258f9f0b32db20050a5b Mon Sep 17 00:00:00 2001
From: Michel Weststrate <mweststrate@fb.com>
Date: Tue, 10 Mar 2020 02:43:37 -0700
Subject: [PATCH] Make changelog part of external rather than internal release

Summary: This makes the changelog generating part of the bump-version process, rather than the build-release

Reviewed By: passy

Differential Revision: D20284211

fbshipit-source-id: f4a5c9bdb98c91f11a216957c9d5175c4b64fe70
---
 CHANGELOG.md                  |  2 +-
 scripts/bump-version.sh       |  3 ++
 scripts/generate-changelog.js | 72 +++++++++++++++++++++++++++++++++++
 static/CHANGELOG.md           |  3 ++
 4 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100755 scripts/generate-changelog.js
 create mode 100644 static/CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ff374a9fe..f5ff88011 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,3 @@
 # Pre-history
 
-Please see our [releases GitHub page](https://github.com/facebook/flipper/releases) for a full list of changes for every release.
+Please see our [releases GitHub page](https://github.com/facebook/flipper/releases) for a full list of changes of old releases.
diff --git a/scripts/bump-version.sh b/scripts/bump-version.sh
index f82ea3a39..7e641eff4 100755
--- a/scripts/bump-version.sh
+++ b/scripts/bump-version.sh
@@ -89,6 +89,9 @@ jq '.version = $newVal' --arg newVal "$VERSION" "$SONAR_DIR"/package.json > tmp.
 #Update react-native-flipper to the very same version
 jq '.version = $newVal' --arg newVal "$VERSION" "$SONAR_DIR"/react-native/react-native-flipper/package.json > tmp.$$.json && mv tmp.$$.json "$SONAR_DIR"/react-native/react-native-flipper/package.json
 
+#Generate changelog
+"$SONAR_DIR"/scripts/generate-changelog.js
+
 echo "Committing the files..."
 hg addremove
 
diff --git a/scripts/generate-changelog.js b/scripts/generate-changelog.js
new file mode 100755
index 000000000..01dc8374a
--- /dev/null
+++ b/scripts/generate-changelog.js
@@ -0,0 +1,72 @@
+#!/usr/bin/env node
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const path = require('path');
+const fs = require('fs');
+const cp = require('child_process');
+
+const root = path.join(__dirname, '..');
+
+const version = JSON.parse(
+  fs.readFileSync(path.join(root, 'package.json'), 'utf8'),
+).version;
+
+const now = new Date();
+const date = `${now.getDate()}/${now.getMonth() + 1}/${now.getFullYear()}`;
+const newlineMarker = '__NEWLINE_MARKER__';
+const fChangelog = path.join(root, 'CHANGELOG.md');
+
+const lastCommit = cp
+  .execSync(`hg log --limit 1 --template '{node}'`, {cwd: root})
+  .toString();
+const firstCommit = cp
+  .execSync(
+    `hg log --limit 1 --template '{node}' --keyword 'Flipper Release: v'`,
+    {cwd: root},
+  )
+  .toString();
+
+console.log(
+  `Generating changelog for version ${version} based on ${firstCommit}..${lastCommit}`,
+);
+
+// # get all commit summaries since last release | find all changelog entries, but make sure there is only one line per commit by temporarily replacing newlines
+const hgLogCommand = `hg log -r "${firstCommit}::${lastCommit} and file('../*')" --template "{phabdiff} - {sub('\n','${newlineMarker}', desc)}\n"`;
+const hgLog = cp.execSync(hgLogCommand).toString();
+
+const diffRe = /^D\d+/;
+const changeLogLineRe = /(^changelog:\s*?)(.*?)$/i;
+
+let contents = `# ${version} (${date})\n\n`;
+let changes = 0;
+
+hgLog
+  .split('\n')
+  .filter(line => diffRe.test(line))
+  .forEach(line => {
+    // Grab the diff nr from every line in the output
+    const diff = line.trim().match(diffRe)[0];
+    // unfold the lines generated by hg log again
+    line.split(newlineMarker).forEach(diffline => {
+      // if a line starts with changelog:, grab the rest of the text and add it to the changelog
+      const match = diffline.match(changeLogLineRe);
+      if (match) {
+        changes++;
+        contents += ` * ${diff} - ${match[2]}\n`;
+      }
+    });
+  });
+
+if (!changes) {
+  console.log('No diffs with changelog items found in this release');
+} else {
+  contents += '\n\n' + fs.readFileSync(fChangelog, 'utf8');
+  fs.writeFileSync(fChangelog, contents);
+}
diff --git a/static/CHANGELOG.md b/static/CHANGELOG.md
new file mode 100644
index 000000000..85a0f2d3e
--- /dev/null
+++ b/static/CHANGELOG.md
@@ -0,0 +1,3 @@
+# Changelog
+
+See [static/CHANGELOG.md](static/CHANGELOG.md)