1 files changed, 96 insertions, 0 deletions
diff --git a/src/flake8/exceptions.py b/src/flake8/exceptions.py
new file mode 100644
index 0000000..5ff55a2
--- /dev/null
+++ b/src/flake8/exceptions.py
@@ -0,0 +1,96 @@
+"""Exception classes for all of Flake8."""
+
+
+class Flake8Exception(Exception):
+    """Plain Flake8 exception."""
+
+    pass
+
+
+class FailedToLoadPlugin(Flake8Exception):
+    """Exception raised when a plugin fails to load."""
+
+    FORMAT = 'Flake8 failed to load plugin "%(name)s" due to %(exc)s.'
+
+    def __init__(self, *args, **kwargs):
+        """Initialize our FailedToLoadPlugin exception."""
+        self.plugin = kwargs.pop('plugin')
+        self.ep_name = self.plugin.name
+        self.original_exception = kwargs.pop('exception')
+        super(FailedToLoadPlugin, self).__init__(*args, **kwargs)
+
+    def __str__(self):
+        """Return a nice string for our exception."""
+        return self.FORMAT % {'name': self.ep_name,
+                              'exc': self.original_exception}
+
+
+class InvalidSyntax(Flake8Exception):
+    """Exception raised when tokenizing a file fails."""
+
+    def __init__(self, *args, **kwargs):
+        """Initialize our InvalidSyntax exception."""
+        self.original_exception = kwargs.pop('exception')
+        self.error_code = 'E902'
+        self.line_number = 1
+        self.column_number = 0
+        try:
+            self.error_message = self.original_exception.message
+        except AttributeError:
+            # On Python 3, the IOError is an OSError which has a
+            # strerror attribute instead of a message attribute
+            self.error_message = self.original_exception.strerror
+        super(InvalidSyntax, self).__init__(*args, **kwargs)
+
+
+class HookInstallationError(Flake8Exception):
+    """Parent exception for all hooks errors."""
+
+    pass
+
+
+class GitHookAlreadyExists(HookInstallationError):
+    """Exception raised when the git pre-commit hook file already exists."""
+
+    def __init__(self, *args, **kwargs):
+        """Initialize the path attribute."""
+        self.path = kwargs.pop('path')
+        super(GitHookAlreadyExists, self).__init__(*args, **kwargs)
+
+    def __str__(self):
+        """Provide a nice message regarding the exception."""
+        msg = ('The Git pre-commit hook ({0}) already exists. To convince '
+               'Flake8 to install the hook, please remove the existing '
+               'hook.')
+        return msg.format(self.path)
+
+
+class MercurialHookAlreadyExists(HookInstallationError):
+    """Exception raised when a mercurial hook is already configured."""
+
+    hook_name = None
+
+    def __init__(self, *args, **kwargs):
+        """Initialize the relevant attributes."""
+        self.path = kwargs.pop('path')
+        self.value = kwargs.pop('value')
+        super(MercurialHookAlreadyExists, self).__init__(*args, **kwargs)
+
+    def __str__(self):
+        """Return a nicely formatted string for these errors."""
+        msg = ('The Mercurial {0} hook already exists with "{1}" in {2}. '
+               'To convince Flake8 to install the hook, please remove the '
+               '{0} configuration from the [hooks] section of your hgrc.')
+        return msg.format(self.hook_name, self.value, self.path)
+
+
+class MercurialCommitHookAlreadyExists(MercurialHookAlreadyExists):
+    """Exception raised when the hg commit hook is already configured."""
+
+    hook_name = 'commit'
+
+
+class MercurialQRefreshHookAlreadyExists(MercurialHookAlreadyExists):
+    """Exception raised when the hg commit hook is already configured."""
+
+    hook_name = 'qrefresh'