Check scripts with shellcheck before accepting new commands

.github/workflows/ci.yml

@@ -19,10 +19,11 @@ jobs:
       - name: Linux Install
         if: matrix.platform == 'ubuntu-18.04'
         run: |
-          sudo apt-get install -y bsdmainutils
+          sudo apt-get install -y bsdmainutils shellcheck
       - name: Script
         run: |
           ./check_integrity.sh $(find bin | cut -b 5- | xargs)
+          ./check_changed_files.sh
       - name: Brew release
         if: matrix.platform == 'macos-latest'
         run: |

check_changed_files.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+err() {
+    echo >&2 "$1"
+    exit 1
+}
+
+if command -v shellcheck > /dev/null ; then
+  # Check all changed shell scripts
+  if ! git diff -z --name-only "$TRAVIS_BRANCH...HEAD" | xargs -0 ./shellcheck.sh ; then
+    err "Please fix the shellcheck issues"
+  fi
+fi

shellcheck.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+files=()
+for f ; do
+  if [ -r "$f" ] ; then
+    file --mime-type -r0 "$f" |
+    cut -d "" -f 2 |
+    grep -q "^: text/x-shellscript$" &&
+    files+=("$f")
+  fi
+done
+if [ ${#files[@]} -gt 0 ] ; then
+  shellcheck "${files[@]}"
+  ret=$?
+  if [ $ret -eq 1 ] || [ $ret -eq 2 ] ; then
+    exit 1
+  fi
+fi