1 files changed, 123 insertions, 0 deletions
diff --git a/gitlint-core/gitlint/lint.py b/gitlint-core/gitlint/lint.py
new file mode 100644
index 0000000..420d3ad
--- /dev/null
+++ b/gitlint-core/gitlint/lint.py
@@ -0,0 +1,123 @@
+import logging
+
+from gitlint import display
+from gitlint import rules as gitlint_rules
+from gitlint.deprecation import Deprecation
+
+LOG = logging.getLogger(__name__)
+logging.basicConfig()
+
+
+class GitLinter:
+    """Main linter class. This is where rules actually get applied. See the lint() method."""
+
+    def __init__(self, config):
+        self.config = config
+
+        self.display = display.Display(config)
+
+    def should_ignore_rule(self, rule):
+        """Determines whether a rule should be ignored based on the general list of commits to ignore"""
+        return rule.id in self.config.ignore or rule.name in self.config.ignore
+
+    @property
+    def configuration_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.ConfigurationRule) and not self.should_ignore_rule(rule)
+        ]
+
+    @property
+    def title_line_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.LineRule)
+            and rule.target == gitlint_rules.CommitMessageTitle
+            and not self.should_ignore_rule(rule)
+        ]
+
+    @property
+    def body_line_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.LineRule)
+            and rule.target == gitlint_rules.CommitMessageBody
+            and not self.should_ignore_rule(rule)
+        ]
+
+    @property
+    def commit_rules(self):
+        return [
+            rule
+            for rule in self.config.rules
+            if isinstance(rule, gitlint_rules.CommitRule) and not self.should_ignore_rule(rule)
+        ]
+
+    @staticmethod
+    def _apply_line_rules(lines, commit, rules, line_nr_start):
+        """Iterates over the lines in a given list of lines and validates a given list of rules against each line"""
+        all_violations = []
+        line_nr = line_nr_start
+        for line in lines:
+            for rule in rules:
+                violations = rule.validate(line, commit)
+                if violations:
+                    for violation in violations:
+                        violation.line_nr = line_nr
+                        all_violations.append(violation)
+            line_nr += 1
+        return all_violations
+
+    @staticmethod
+    def _apply_commit_rules(rules, commit):
+        """Applies a set of rules against a given commit and gitcontext"""
+        all_violations = []
+        for rule in rules:
+            violations = rule.validate(commit)
+            if violations:
+                all_violations.extend(violations)
+        return all_violations
+
+    def lint(self, commit):
+        """Lint the last commit in a given git context by applying all ignore, title, body and commit rules."""
+        LOG.debug("Linting commit %s", commit.sha or "[SHA UNKNOWN]")
+        LOG.debug("Commit Object\n" + str(commit))
+
+        # Ensure the Deprecation class has a reference to the config currently being used
+        Deprecation.config = self.config
+
+        # Apply config rules
+        for rule in self.configuration_rules:
+            rule.apply(self.config, commit)
+
+        # Skip linting if this is a special commit type that is configured to be ignored
+        ignore_commit_types = ["merge", "squash", "fixup", "fixup_amend", "revert"]
+        for commit_type in ignore_commit_types:
+            if getattr(commit, f"is_{commit_type}_commit") and getattr(self.config, f"ignore_{commit_type}_commits"):
+                return []
+
+        violations = []
+        # determine violations by applying all rules
+        violations.extend(self._apply_line_rules([commit.message.title], commit, self.title_line_rules, 1))
+        violations.extend(self._apply_line_rules(commit.message.body, commit, self.body_line_rules, 2))
+        violations.extend(self._apply_commit_rules(self.commit_rules, commit))
+
+        # Sort violations by line number and rule_id. If there's no line nr specified (=common certain commit rules),
+        # we replace None with -1 so that it always get's placed first. Note that we need this to do this to support
+        # python 3, as None is not allowed in a list that is being sorted.
+        violations.sort(key=lambda v: (-1 if v.line_nr is None else v.line_nr, v.rule_id))
+        return violations
+
+    def print_violations(self, violations):
+        """Print a given set of violations to the standard error output"""
+        for v in violations:
+            line_nr = v.line_nr if v.line_nr else "-"
+            self.display.e(f"{line_nr}: {v.rule_id}", exact=True)
+            self.display.ee(f"{line_nr}: {v.rule_id} {v.message}", exact=True)
+            if v.content:
+                self.display.eee(f'{line_nr}: {v.rule_id} {v.message}: "{v.content}"', exact=True)
+            else:
+                self.display.eee(f"{line_nr}: {v.rule_id} {v.message}", exact=True)