Add single-char variable check workflow

.github/scripts/check_single_char_vars.py

@@ -0,0 +1,80 @@
+import os
+import re
+import sys
+
+
+def split_params(param_string: str):
+    """Split a function parameter string on commas while ignoring brackets."""
+    params = []
+    current = ""
+    depth = 0
+    for char in param_string:
+        if char == '[':
+            depth += 1
+        elif char == ']':
+            depth = max(0, depth - 1)
+        if char == ',' and depth == 0:
+            params.append(current.strip())
+            current = ""
+            continue
+        current += char
+    if current:
+        params.append(current.strip())
+    return params
+
+EXCLUDED_DIRS = {"addons", ".git", ".github"}
+
+single_char_vars = []
+
+# Patterns reused from check_gd_nomenclature.py
+VAR_PATTERN = re.compile(r"(?:@\w+\s+)*var\s+([A-Za-z0-9_]+)")
+FUNC_PATTERN = re.compile(r"func\s+[A-Za-z0-9_]+\s*(\([^)]*\))?")
+FOR_PATTERN = re.compile(r"for\s+([A-Za-z0-9_]+)(?:\s*:\s*[^\s]+)?\s+in\b")
+
+for root, dirs, files in os.walk('.', topdown=True):
+    rel_root = os.path.relpath(root, '.')
+    if any(rel_root == ex or rel_root.startswith(f"{ex}{os.sep}") for ex in EXCLUDED_DIRS):
+        dirs[:] = []
+        continue
+    for fname in files:
+        if fname.endswith('.gd'):
+            path = os.path.join(root, fname)
+            try:
+                with open(path, 'r', encoding='utf-8') as f:
+                    lines = f.readlines()
+            except Exception as e:
+                continue
+            for idx, line in enumerate(lines, 1):
+                stripped = line.strip()
+                if stripped.startswith('#') or not stripped:
+                    continue
+
+                m = VAR_PATTERN.match(stripped)
+                if m:
+                    name = m.group(1)
+                    if len(name) == 1:
+                        single_char_vars.append((path, idx, name))
+
+                m = FUNC_PATTERN.match(stripped)
+                if m:
+                    params = m.group(1)
+                    if params:
+                        params = params.strip('()')
+                        for param in split_params(params):
+                            param_name = param.split(':')[0].split('=')[0].strip()
+                            if param_name and len(param_name) == 1:
+                                single_char_vars.append((path, idx, param_name))
+
+                m = FOR_PATTERN.match(stripped)
+                if m:
+                    name = m.group(1)
+                    if len(name) == 1:
+                        single_char_vars.append((path, idx, name))
+
+if single_char_vars:
+    print(f"{len(single_char_vars)} errors found:")
+    for path, idx, name in single_char_vars:
+        print(f"{path}:{idx}: variable '{name}' has a single-character name")
+    sys.exit(1)
+else:
+    print("No single-character variable names found.")

.github/workflows/gdscript-single-char-vars.yml

@@ -0,0 +1,34 @@
+name: Single Character Variable Check
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  single_char_vars:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v3
+      - name: Run single character variable check
+        id: single
+        run: |
+          python3 .github/scripts/check_single_char_vars.py > single_char_vars_output.txt
+        continue-on-error: true
+      - name: Comment on PR with single character variable output
+        if: steps.single.outcome != 'success'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            const body = fs.readFileSync('single_char_vars_output.txt', 'utf8');
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body,
+            });
+      - name: Fail if single character variable check failed
+        if: steps.single.outcome != 'success'
+        run: exit 1