Lint whitespace during CI

.github/workflows/main-ci.yml

@@ -37,3 +37,6 @@ jobs:
         test -f bin/illuaminate || wget -q -Obin/illuaminate https://squiddev.cc/illuaminate/bin/illuaminate
         chmod +x bin/illuaminate
         bin/illuaminate lint
+
+    - name: Check whitespace
+      run: python3 tools/check-lines.py

tools/check-lines.py

@@ -0,0 +1,28 @@
+import pathlib, sys
+
+problems = False
+
+# Skip images and files without extensions
+exclude = [ ".png", "" ]
+
+for path in pathlib.Path(".").glob("src/**/*"):
+    if path.is_dir() or path.suffix in exclude:
+        continue
+
+    with path.open(encoding="utf-8") as file:
+        has_dos, has_trailing, needs_final = False, False, False
+        for i, line in enumerate(file):
+            if len(line) >= 2 and line[-2] == "\r" and line[-1] == "\n" and not has_line:
+                print("%s has contains '\\r\\n' on line %d" % (path, i + 1))
+                problems = has_dos = True
+
+            if len(line) >= 2 and line[-2] in " \t" and line[-1] == "\n" and not has_trailing:
+                print("%s has trailing whitespace on line %d" % (path, i + 1))
+                problems = has_trailing = True
+
+        if line is not None and len(line) >= 1 and line[-1] != "\n":
+            print("%s should end with '\\n'" % path)
+            problems = True
+
+if problems:
+    sys.exit(1)