[WIP] Add support for linting a range of commits natively.

Fixes #14.

gitlint/cli.py

@@ -70,6 +70,7 @@ def build_config(ctx, target, config_path, c, extra_path, ignore, verbose, silen
 @click.option('-c', multiple=True,
               help="Config flags in format <rule>.<option>=<value> (e.g.: -c T1.line-length=80). " +
                    "Flag can be used multiple times to set multiple config values.")  # pylint: disable=bad-continuation
+@click.option('--commits', default='HEAD^...', help="The range of commits to lint.")
 @click.option('-e', '--extra-path', help="Path to a directory with extra user-defined rules",
               type=click.Path(exists=True, resolve_path=True, file_okay=False, readable=True))
 @click.option('--ignore', default="", help="Ignore rules (comma-separated by id or name).")
@@ -79,14 +80,14 @@ def build_config(ctx, target, config_path, c, extra_path, ignore, verbose, silen
 @click.option('-d', '--debug', help="Enable debugging output.", is_flag=True)
 @click.version_option(version=gitlint.__version__)
 @click.pass_context
-def cli(ctx, target, config, c, extra_path, ignore, verbose, silent, debug):
+def cli(ctx, target, config, c, commits, extra_path, ignore, verbose, silent, debug):
     """ Git lint tool, checks your git commit messages for styling issues """
 
     # Get the lint config from the commandline parameters and
     # store it in the context (click allows storing an arbitrary object in ctx.obj).
     config, config_builder = build_config(ctx, target, config, c, extra_path, ignore, verbose, silent, debug)
 
-    ctx.obj = (config, config_builder)
+    ctx.obj = (config, config_builder, commits)
 
     # If no subcommand is specified, then just lint
     if ctx.invoked_subcommand is None:
@@ -101,7 +102,7 @@ def lint(ctx):
     try:
         if sys.stdin.isatty():
             # If target has not been set explicitly before, fallback to the current directory
-            gitcontext = GitContext.from_local_repository(lint_config.target)
+            gitcontext = GitContext.from_local_repository(lint_config.target, ctx.obj[2])
         else:
             stdin_str = ustr(sys.stdin.read())
             gitcontext = GitContext.from_commit_msg(stdin_str)
@@ -117,8 +118,16 @@ def lint(ctx):
 
     # Let's get linting!
     linter = GitLinter(lint_config)
-    violations = linter.lint(last_commit)
-    linter.print_violations(violations)
+    number_of_commits = len(gitcontext.commits)
+    for index, commit in enumerate(gitcontext.commits):
+        violations = linter.lint(commit)
+        if violations:
+            click.echo(u"{0}Commit {1}:".format(
+                "\n" if index not in [0, number_of_commits] else "",
+                commit.sha[:10]
+            ))
+            linter.print_violations(violations)
+
     exit_code = min(MAX_VIOLATION_ERROR_CODE, len(violations))
     ctx.exit(exit_code)
 

gitlint/git.py

@@ -54,10 +54,11 @@ class GitCommit(object):
         In the context of gitlint, only the git context and commit message are required.
     """
 
-    def __init__(self, context, message, date=None, author_name=None, author_email=None, parents=None,
+    def __init__(self, context, message, sha, date=None, author_name=None, author_email=None, parents=None,
                  is_merge_commit=False, changed_files=None):
         self.context = context
         self.message = message
+        self.sha = sha
         self.author_name = author_name
         self.author_email = author_email
         self.date = date
@@ -117,10 +118,12 @@ def from_commit_msg(commit_msg_str):
         return context
 
     @staticmethod
-    def from_local_repository(repository_path):
+    def from_local_repository(repository_path, refspec="HEAD^..."):
         """ Retrieves the git context from a local git repository.
         :param repository_path: Path to the git repository to retrieve the context from
+        :param refspec: The commit(s) to retrieve
         """
+
         context = GitContext()
         try:
             # Special arguments passed to sh: http://amoffat.github.io/sh/special_arguments.html
@@ -129,18 +132,36 @@ def from_local_repository(repository_path):
                 '_cwd': repository_path
             }
 
+            sha_list = sh.git("rev-list", refspec, **sh_special_args).split()
+
             # Get info from the local git repository
             # https://git-scm.com/docs/pretty-formats
-            commit_msg = sh.git.log("-1", "--pretty=%B", **sh_special_args)
-            commit_author_name = sh.git.log("-1", "--pretty=%aN", **sh_special_args)
-            commit_author_email = sh.git.log("-1", "--pretty=%aE", **sh_special_args)
-            # %aI -> ISO 8601-like format, while %aI is strict ISO 8601, it seems to be less widely supporte
-            commit_date_str = sh.git.log("-1", "--pretty=%ai", **sh_special_args)
-            commit_parents = sh.git.log("-1", "--pretty=%P", **sh_special_args).split(" ")
-            commit_is_merge_commit = len(commit_parents) > 1
-
-            # changed files in last commit
-            changed_files_str = sh.git("diff-tree", "--no-commit-id", "--name-only", "-r", "HEAD", **sh_special_args)
+            for sha in sha_list:
+                raw_commit = sh.git.log(sha, "-n 1", "--pretty=%aN,%aE,%ai,%P%n%B", **sh_special_args).split("\n")
+                meta_data, commit_msg = raw_commit[0], "\n".join(raw_commit[1:])
+
+                name, email, date, parents = meta_data.split(",")
+
+                commit_parents = parents.split(" ")
+                commit_is_merge_commit = len(commit_parents) > 1
+
+                # changed files in last commit
+                changed_files = sh.git("diff-tree", "--no-commit-id", "--name-only",
+                                       "-r", sha, **sh_special_args).split("\n")
+
+                # "YYYY-MM-DD HH:mm:ss Z" -> ISO 8601-like format
+                # Use arrow for datetime parsing, because apparently python is quirky around ISO-8601 dates:
+                # http://stackoverflow.com/a/30696682/381010
+                commit_date = arrow.get(ustr(date), "YYYY-MM-DD HH:mm:ss Z").datetime
+
+                # Create Git commit object with the retrieved info
+                commit_msg_obj = GitCommitMessage.from_full_message(commit_msg)
+                commit = GitCommit(context, commit_msg_obj, sha, author_name=name,
+                                   author_email=email, date=commit_date, changed_files=changed_files,
+                                   parents=commit_parents, is_merge_commit=commit_is_merge_commit)
+
+                context.commits.append(commit)
+
         except CommandNotFound:
             error_msg = u"'git' command not found. You need to install git to use gitlint on a local repository. " + \
                         u"See https://git-scm.com/book/en/v2/Getting-Started-Installing-Git on how to install git."
@@ -153,21 +174,6 @@ def from_local_repository(repository_path):
                 error_msg = u"An error occurred while executing '{0}': {1}".format(e.full_cmd, error_msg)
             raise GitContextError(error_msg)
 
-        # "YYYY-MM-DD HH:mm:ss Z" -> ISO 8601-like format
-        # Use arrow for datetime parsing, because apparently python is quirky around ISO-8601 dates:
-        # http://stackoverflow.com/a/30696682/381010
-        commit_date = arrow.get(ustr(commit_date_str), "YYYY-MM-DD HH:mm:ss Z").datetime
-
-        # Create Git commit object with the retrieved info
-        changed_files = [changed_file for changed_file in changed_files_str.strip().split("\n")]
-        commit_msg_obj = GitCommitMessage.from_full_message(commit_msg)
-        commit = GitCommit(context, commit_msg_obj, author_name=commit_author_name, author_email=commit_author_email,
-                           date=commit_date, changed_files=changed_files, parents=commit_parents,
-                           is_merge_commit=commit_is_merge_commit)
-
-        # Create GitContext info with the commit object and return
-
-        context.commits.append(commit)
         return context
 
     def __eq__(self, other):