Add Action CI job to validate patches for PRs

Adds a GitHub Action job and python script that run on PR creation and commit push to a PR branch and validates all patches in the repository to report any errors/issues with the patches it finds..

Currently it will detect the following issues:
- Patch group headers straight brackets unclosed e.g. [name
- Non-lowercase gametitle,comment,author,gsaspectratio,gsinterlacemode,description keywords (if case is incorrect, these lines will get ignored)
- Patches that are missing fields, have an invalid field value,  or are otherwise malformed. (Including incorrect casing)
- Broken comments at the end of a patch line (which break the line)
- Invalid comment lines/other garbage lines (of which many will be cleaned up with this PR).

.github/scripts/validate_patches.py

@@ -0,0 +1,76 @@
+import os
+import re
+import sys
+import glob
+
+patches_folder_path = os.path.abspath('./patches/')
+patches_glob_path = './patches/*.pnach'
+
+def remove_comments(line):
+    return line[0:line.index('//')] if ("//" in line) else line
+
+def clean_line(line):
+    return remove_comments(line).strip()
+
+def log_error(file_path, line_number, message, line, shouldCleanLine = False):
+    line = line.replace("\n", "")
+    line = (clean_line(line) if shouldCleanLine else line)
+    print(f'Error in {file_path} (line {line_number}): {message}\n\t"{line}"')
+
+def is_file_valid(file_path):
+    with open(file_path, 'r') as file:
+        for line_number, line in enumerate(file, 1):
+            cleaned_line = clean_line(line)
+            if cleaned_line == "":
+                continue
+            elif cleaned_line.startswith("["):
+                if not cleaned_line.endswith("]"):
+                    print(f'Error in {file_path} group format (line {line_number}): Unclosed brackets for group.\n\T"{line}"')
+                    return False
+                continue
+            elif re.match(r'^(\s*(gametitle|comment|gsaspectratio|gsinterlacemode|author|description)\s*=)', line, re.IGNORECASE):
+                # Incorrect case will cause the line to be ignored by the emulator.
+                # Conditional is case insensitive to catch any case issues and compare to lower.
+                line_keyword = cleaned_line.split('=')[0]
+                if line_keyword != line_keyword.lower():
+                    log_error(file_path, line_number, "Invalid keyword format.", line)
+                    return False
+                # We can do more validations here, but for now skip these so they don't appear as unknown syntax error.
+                continue
+            elif cleaned_line.startswith("patch"):
+                if not re.match(r'^patch=(0|1|2),(EE|IOP),[0-9A-Fa-f]{1,8},(byte|short|word|double|extended|beshort|beword|bedouble|bytes),[0-9A-Fa-f]{1,8}', line):
+                    log_error(file_path, line_number, "Invalid patch format.", line, True)
+                    return False
+                if re.match(",\d{8}(\n|\s*(//.*)*)+(?!.)", line):
+                    log_error(file_path, line_number, "Invalid comment syntax at end of patch line.", line, False)
+                    return False
+            else:
+                log_error(file_path, line_number, "Unknown line format.", line, True)
+                return False
+            
+    return True
+
+def main():
+    error_found = False
+    print('Started validating patches files')
+
+    files = glob.glob(patches_glob_path)
+    file_count = len(files)
+    print(f'Validating {file_count} patch files:')
+    if file_count > 0:
+        for file_path in files:
+            if not is_file_valid(file_path):
+                error_found = True
+    else:
+        print(f'[Error]: No patch files found to validate in \'{patches_folder_path}\'')
+        error_found = True
+
+    if error_found:
+        print('[Failed]: Patch validation issues were detected. Ending checks.')
+        sys.exit(1)
+
+    print('[Success]: All patch files passed the validation checks.')
+    sys.exit(0)
+
+if __name__ == '__main__':
+    main()

.github/workflows/validate_patches.yml

@@ -0,0 +1,17 @@
+name: Validate Patch PR
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  check-patches:
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v2
+
+      - name: Validate all patches
+        run: |
+          python .github/scripts/validate_patches.py