Add script for checking git commit is safe

scripts/safe-commit-linter.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+set -e
+
+###############################################################################
+#
+#   safe-commit-linter.sh
+#
+#   Executes safe_template_linter.py on the set of files in a particular git
+#   commit.
+#
+###############################################################################
+
+show_help() {
+    echo "Usage: safe-commit-linter.sh [OPTION]"
+    echo "Runs the Safe Template Linter against all files in a git commit."
+    echo ""
+    echo "Mandatory arguments to long options are mandatory for short options too."
+    echo "  -m, --main-branch=COMMIT    Run against files changed between the"
+    echo "                              current branch and this commit."
+    echo "                              Defaults to origin/master."
+}
+
+for i in "$@"; do
+    case $i in
+        -m=*|--main-branch=*)
+            MAIN_COMMIT="${i#*=}"
+            shift # past argument=value
+            ;;
+        -h|--help|*)
+            # help or unknown option
+            show_help
+            exit 0
+            ;;
+    esac
+done
+
+current_branch_hash=`git rev-parse HEAD`
+
+if [ -z "${MAIN_COMMIT+x}" ]; then
+    # if commit is not set, get hash of current branch
+    MAIN_COMMIT="origin/master"
+fi
+
+merge_base=`git merge-base "$current_branch_hash" "$MAIN_COMMIT"`
+diff_files=`git diff --name-only "$current_branch_hash" "$merge_base"`
+
+for f in $diff_files; do
+    echo ""
+    echo "Linting $f:"
+    ./scripts/safe_template_linter.py $f
+done