Add file-header-path option

Use a file to store a long multi-line header instead of putting it to the pylint config.

Author: Sergey Vilgelm

pylintfileheader/file_header_checker.py

@@ -36,6 +36,15 @@ class FileHeaderChecker(BaseChecker):
                 'help': 'The file header that should be on top of a file.',
             }
         ),
+        (
+            'file-header-path',
+            {
+                'default': None,
+                'type': 'string',
+                'metavar': '<file>',
+                'help': 'The path to the file that contains the header.',
+            }
+        ),
         (
             'file-header-ignore-empty-files',
             {
@@ -47,27 +56,39 @@ class FileHeaderChecker(BaseChecker):
         ),
     )
 
-    def process_module(self, node):
-        """Process the astroid node stream."""
-        if self.config.file_header:
-            content = None
-            with node.stream() as stream:
-                # Explicit decoding required by python 3
-                content = stream.read().decode('utf-8')
+    def __init__(self, linter=None):
+        super(FileHeaderChecker, self).__init__(linter=linter)
+        self.pattern = None
+        self.header = None
 
-            if self.config.file_header_ignore_empty_files and not content:
-                return
+    def open(self):
+        self.header = self.config.file_header
+        if not self.header and self.config.file_header_path:
+            with open(self.config.file_header_path, 'r') as f:
+                self.header = f.read()
 
+        if self.header:
             if sys.version_info[0] < 3:
-                pattern = re.compile(
-                    r'\A' + self.config.file_header, re.LOCALE | re.MULTILINE)
+                opts = re.LOCALE | re.MULTILINE
             else:
-                # The use of re.LOCALE is discouraged in python 3
-                pattern = re.compile(
-                    r'\A' + self.config.file_header, re.MULTILINE)
+                opts = re.MULTILINE
+            self.pattern = re.compile(r'\A' + self.header, opts)
+
+    def process_module(self, node):
+        """Process the astroid node stream."""
+
+        if self.pattern is None:
+            return
+
+        content = None
+        with node.stream() as stream:
+            # Explicit decoding required by python 3
+            content = stream.read().decode('utf-8')
+
+        if self.config.file_header_ignore_empty_files and not content:
+            return
 
-            matches = pattern.findall(content)
+        matches = self.pattern.findall(content)
 
-            if len(matches) != 1:
-                self.add_message('invalid-file-header', 1,
-                                 args=self.config.file_header)
+        if len(matches) != 1:
+            self.add_message('invalid-file-header', 1, args=self.header)

pylintfileheadertest/file_header_checker_test.py

@@ -43,15 +43,6 @@ def test_valid_header_not_at_top_message_added(self):
                 args='# Valid\n# Header')):
             self.checker.process_module(node_mock)
 
-    def test_config_empty_no_message_added(self):
-        """When the `file-header` option is not set, no message should be added."""
-
-        self.checker.config.file_header = None
-        node_mock = MagicMock()
-        node_mock.stream.return_value.__enter__.return_value.read.return_value.decode.return_value = '# Invalid\n# Header'
-        with self.assertNoMessages():
-            self.checker.process_module(node_mock)
-
     def test_ignore_empty_files(self):
         """When the `file-header-ignore-empty-files` option is set to True."""
 
@@ -71,3 +62,22 @@ def test_do_not_ignore_empty_files(self):
                 line=1,
                 args='# Valid\n# Header')):
             self.checker.process_module(node_mock)
+
+
+class TestFileHeaderCheckerNoConfig(pylint.testutils.CheckerTestCase):
+    CHECKER_CLASS = FileHeaderChecker
+    CONFIG = {}
+
+    def test_no_message_added(self):
+        """When the `file-header` option is not set, no message should be added."""
+
+        self.checker.config.file_header = None
+        node_mock = MagicMock()
+        node_mock.stream.return_value.__enter__.return_value.read.return_value.decode.return_value = '# Invalid\n# Header'
+        with self.assertNoMessages():
+            self.checker.process_module(node_mock)
+
+
+class TestFileHeaderCheckerPath(TestFileHeaderChecker):
+    CHECKER_CLASS = FileHeaderChecker
+    CONFIG = {'file_header_path': 'pylintfileheadertest/header.txt'}

pylintfileheadertest/header.txt

@@ -0,0 +1,2 @@
+# Valid
+# Header