1 files changed, 101 insertions, 0 deletions
diff --git a/ci/check-whitespace.sh b/ci/check-whitespace.sh
new file mode 100755
index 0000000000..c40804394c
--- /dev/null
+++ b/ci/check-whitespace.sh
@@ -0,0 +1,101 @@
+#!/usr/bin/env bash
+#
+# Check that commits after a specified point do not contain new or modified
+# lines with whitespace errors. An optional formatted summary can be generated
+# by providing an output file path and url as additional arguments.
+#
+
+baseCommit=$1
+outputFile=$2
+url=$3
+
+if test "$#" -ne 1 && test "$#" -ne 3 || test -z "$1"
+then
+	echo "USAGE: $0 <BASE_COMMIT> [<OUTPUT_FILE> <URL>]"
+	exit 1
+fi
+
+problems=()
+commit=
+commitText=
+commitTextmd=
+goodParent=
+
+if ! git rev-parse --quiet --verify "${baseCommit}"
+then
+    echo "Invalid <BASE_COMMIT> '${baseCommit}'"
+    exit 1
+fi
+
+while read dash sha etc
+do
+	case "${dash}" in
+	"---") # Line contains commit information.
+		if test -z "${goodParent}"
+		then
+			# Assume the commit has no whitespace errors until detected otherwise.
+			goodParent=${sha}
+		fi
+
+		commit="${sha}"
+		commitText="${sha} ${etc}"
+		commitTextmd="[${sha}](${url}/commit/${sha}) ${etc}"
+		;;
+	"")
+		;;
+	*) # Line contains whitespace error information for current commit.
+		if test -n "${goodParent}"
+		then
+			problems+=("1) --- ${commitTextmd}")
+			echo ""
+			echo "--- ${commitText}"
+			goodParent=
+		fi
+
+		case "${dash}" in
+		*:[1-9]*:) # contains file and line number information
+			dashend=${dash#*:}
+			problems+=("[${dash}](${url}/blob/${commit}/${dash%%:*}#L${dashend%:}) ${sha} ${etc}")
+			;;
+		*)
+			problems+=("\`${dash} ${sha} ${etc}\`")
+			;;
+		esac
+		echo "${dash} ${sha} ${etc}"
+		;;
+	esac
+done <<< "$(git log --check --pretty=format:"---% h% s" "${baseCommit}"..)"
+
+if test ${#problems[*]} -gt 0
+then
+	if test -z "${goodParent}"
+	then
+		goodParent=${baseCommit: 0:7}
+	fi
+
+	echo "A whitespace issue was found in one or more of the commits."
+	echo "Run the following command to resolve whitespace issues:"
+	echo "git rebase --whitespace=fix ${goodParent}"
+
+	# If target output file is provided, write formatted output.
+	if test -n "$outputFile"
+	then
+		echo "🛑 Please review the Summary output for further information."
+		(
+			echo "### :x: A whitespace issue was found in one or more of the commits."
+			echo ""
+			echo "Run these commands to correct the problem:"
+			echo "1. \`git rebase --whitespace=fix ${goodParent}\`"
+			echo "1. \`git push --force\`"
+			echo ""
+			echo "Errors:"
+
+			for i in "${problems[@]}"
+			do
+				echo "${i}"
+			done
+		) >"$outputFile"
+	fi
+
+	exit 2
+fi