1 files changed, 53 insertions, 19 deletions
diff --git a/development/auto-changelog.sh b/development/auto-changelog.sh
index f9f577ade..3ed059b3d 100755
--- a/development/auto-changelog.sh
+++ b/development/auto-changelog.sh
@@ -1,26 +1,60 @@
-#! /bin/bash
-# update tags
+#!/usr/bin/env bash
+
+set -e
+set -u
+set -o pipefail
+
+readonly URL='https://github.com/MetaMask/metamask-extension'
+
 git fetch --tags
-# get origin
-URL='https://github.com/MetaMask/metamask-extension'
-# get git logs from last tag until HEAD, pretty by 'subject::body' filtered by grep for PRs made with Github squash merge or Github regular merge
-LOG=$(git log $(git describe --tags $(git rev-list --tags --max-count=1))..HEAD --pretty="%s::%b" --reverse --grep="Merge pull request #" --grep="(#");
-while read -r line; do
-    # get git log subject
-    SUBJECT=$(echo $line | sed -E 's/(.*):{2}(.*)/\1/')
-    # get git log PR id, PR made with Github squash merge or Github regular merge
-    PR=$(echo $SUBJECT | sed 's/^.*(#\([^&]*\)).*/\1/' | sed 's/^.*#\([^&]*\) from.*/\1/')
-    # if PR made with Github squash merge, subject is the body
-    if [ -z "$(echo $line | sed -E 's/(.*):{2}(.*)/\2/')" ]; then
-        BODY=$(echo $SUBJECT | sed "s/(#$PR)//g"); else
-        BODY=$(echo $line | sed -E 's/(.*):{2}(.*)/\2/') 
+
+most_recent_tag="$(git describe --tags "$(git rev-list --tags --max-count=1)")"
+
+git rev-list "${most_recent_tag}"..HEAD | while read commit
+do
+    subject="$(git show -s --format="%s" "$commit")"
+
+    # Squash & Merge: the commit subject is parsed as `<description> (#<PR ID>)`
+    if grep -E -q '\(#[[:digit:]]+\)' <<< "$subject"
+    then
+        pr="$(awk '{print $NF}' <<< "$subject" | tr -d '()')"
+        prefix="[$pr]($URL/pull/${pr###}): "
+        description="$(awk '{NF--; print $0}' <<< "$subject")"
+
+    # Merge: the PR ID is parsed from the git subject (which is of the form `Merge pull request
+    #   #<PR ID> from <branch>`, and the description is assumed to be the first line of the body.
+    #   If no body is found, the description is set to the commit subject
+    elif grep -E -q '#[[:digit:]]+\sfrom' <<< "$subject"
+    then
+        pr="$(awk '{print $4}' <<< "$subject")"
+        prefix="[$pr]($URL/pull/${pr###}): "
+
+        first_line_of_body="$(git show -s --format="%b" "$commit" | head -n 1 | tr -d '\r')"
+        if [[ -z "$first_line_of_body" ]]
+        then
+            description="$subject"
+        else
+            description="$first_line_of_body"
+        fi
+
+    # Normal commits: The commit subject is the description, and the PR ID is omitted.
+    else
+        pr=''
+        prefix=''
+        description="$subject"
     fi
+
     # add entry to CHANGELOG
-    if [[ "$OSTYPE" == "linux-gnu" ]]; then
+    if [[ "$OSTYPE" == "linux-gnu" ]]
+    then
+        # shellcheck disable=SC1004
         sed -i'' '/## Current Develop Branch/a\
-- [#'"$PR"']('"$URL"'/pull/'"$PR"'): '"$BODY"''$'\n' CHANGELOG.md; else
+- '"$prefix$description"''$'\n' CHANGELOG.md
+    else
+        # shellcheck disable=SC1004
         sed -i '' '/## Current Develop Branch/a\
-- [#'"$PR"']('"$URL"'/pull/'"$PR"'): '"$BODY"''$'\n' CHANGELOG.md;
+- '"$prefix$description"''$'\n' CHANGELOG.md
     fi
-done <<< "$LOG"
+done
+
 echo 'CHANGELOG updated'