misc: gitlint: python code improvements

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

scripts/gitlint/rules/BodyMaxLineLengthEx.py

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from gitlint.rules import LineRule, RuleViolation, CommitMessageBody
+from typing import List, Optional
 import re
 
 
@@ -29,9 +30,23 @@ IGNORE_PREFIXES = [
     "\t",
 ]
 
+# Pattern allowing:
+# - [0]: https://example.com
+# - [0] https://example.com
+# - https://example.com
+LINK_REGEX = re.compile(r"^(([\[0-9]+]:?\s?)?https?://).*$")
+
+MAX_LEN = 72
+
 
 class BodyMaxLineLengthEx(LineRule):
-    """A rule to enforce a line limit of 72 characters, except for valid cases."""
+    """
+    A rule to enforce a line limit of 72 characters, except for valid cases:
+
+    - Markdown-style code blocks
+    - Commit tags, such as Signed-off-by
+    - Links
+    """
 
     # A rule MUST have a human friendly name
     name = "body-max-line-length-ex"
@@ -43,38 +58,34 @@ class BodyMaxLineLengthEx(LineRule):
     # A line-rule MUST have a target (not required for CommitRules).
     target = CommitMessageBody
 
-    max_len = 72
-
     # Updated property as the commit messages is validated line by line.
     inside_open_codeblock = False
 
-    def validate(self, line, commit):
-        # Pattern allowing:
-        # - [0]: https://foobar
-        # - [0] https://foobar
-        # - https://foobar
-        link_regex = re.compile(r"^((\[[0-9]+\]:?\s?)?https?:\/\/).*$")
-
+    def validate(self, line, commit) -> Optional[List[RuleViolation]]:
+        # We keep track of whether we are in an open code block.
         is_codeblock_marker = line.startswith("```")
-
         inside_open_codeblock_ = self.inside_open_codeblock
         if is_codeblock_marker:
             self.inside_open_codeblock = not self.inside_open_codeblock
 
-        if len(line) > self.max_len:
-            is_link = link_regex.match(line)
+        # Begin checks
+        if len(line) <= MAX_LEN:
+            return None
 
-            if inside_open_codeblock_:
-                return
+        if inside_open_codeblock_:
+            return None
 
-            if is_link:
-                return
+        if None is not LINK_REGEX.match(line):
+            return None
 
-            # Don't check lines with allowed prefixes
-            for prefix in IGNORE_PREFIXES:
-                if line.startswith(prefix):
-                    return None
+        # Don't check lines with allowed prefixes
+        for prefix in IGNORE_PREFIXES:
+            if line.startswith(prefix):
+                return None
 
-            return [
-                RuleViolation(self.id, f"Line '{line}' exceeds limit of {self.max_len}")
-            ]
+        return [
+            RuleViolation(
+                self.id,
+                f"Line '{line}' exceeds limit of {MAX_LEN}: {len(line)}",
+            )
+        ]