Merge pull request #66 from insightindustry/issue-63-mimetype-validator

Closes #63 by adding a MIME type validator and checker.

Author: insightindustry

README.rst

@@ -215,7 +215,7 @@ Validators
     -
     -
     - ``writeable``
-    -
+    - ``mimetype``
   * -
     -
     -
@@ -275,7 +275,7 @@ Checkers
     -
     -
     - ``is_writeable``
-    -
+    - ``is_mimetype``
   * - ``is_iterable``
     -
     -

docs/_checker_list.rst

@@ -51,7 +51,7 @@
     -
     -
     - :func:`is_executable <validator_collection.checkers.is_executable>`
-    -
+    - :func:`is_mimetype <validator_collection.checkers.is_mimetype>`
   * - :func:`is_not_empty <validator_collection.checkers.is_not_empty>`
     -
     -

docs/_validator_list.rst

@@ -46,7 +46,7 @@
     -
     -
     - :func:`writeable <validator_collection.validators.writeable>`
-    -
+    - :func:`mimetype <validator_collection.validators.mimetype>`
   * -
     -
     -

docs/checkers.rst

@@ -235,3 +235,8 @@ is_mac_address
 -------------------
 
 .. autofunction:: is_mac_address
+
+is_mimetype
+-------------------
+
+.. autofunction:: is_mimetype

docs/errors.rst

@@ -369,3 +369,8 @@ InvalidMACAddressError (from :class:`ValueError <python:ValueError>`)
 -----------------------------------------------------------------------
 
 .. autoclass:: InvalidMACAddressError
+
+InvalidMimeTypeError (from :class:`ValueError <python:ValueError>`)
+-----------------------------------------------------------------------
+
+.. autoclass:: InvalidMimeTypeError

docs/validators.rst

@@ -222,3 +222,8 @@ mac_address
 --------------
 
 .. autofunction:: mac_address
+
+mimetype
+--------------
+
+.. autofunction:: mimetype

tests/test_checkers.py

@@ -1595,3 +1595,25 @@ def is_mac_address(value, **kwargs):
         return False
 
     return True
+
+
+@disable_checker_on_env
+def is_mimetype(value, **kwargs):
+    """Indicate whether ``value`` is a valid MIME type.
+
+    :param value: The value to evaluate.
+
+    :returns: ``True`` if ``value`` is valid, ``False`` if it is not.
+    :rtype: :class:`bool <python:bool>`
+
+    :raises SyntaxError: if ``kwargs`` contains duplicate keyword parameters or duplicates
+      keyword parameters passed to the underlying validator
+    """
+    try:
+        value = validators.mimetype(value, **kwargs)
+    except SyntaxError as error:
+        raise error
+    except Exception:
+        return False
+
+    return True

tests/test_validators.py

@@ -148,6 +148,14 @@ class InvalidMACAddressError(ValueError):
     """
     pass
 
+class InvalidMimeTypeError(ValueError):
+    """Exception raised when a value is not a valid MIME type.
+
+    **INHERITS FROM:** :class:`ValueError <python:ValueError>`
+
+    """
+    pass
+
 
 class CannotCoerceError(TypeError):
     """Exception raised when a value cannot be coerced to an expected type.

validator_collection/checkers.py

@@ -134,6 +134,8 @@
 TIMEDELTA_REGEX = re.compile(r'((?P<days>\d+) days?, )?(?P<hours>\d+):'
                              r'(?P<minutes>\d+):(?P<seconds>\d+(\.\d+)?)')
 
+MIME_TYPE_REGEX = re.compile(r"^multipart|[-\w.]+/[-\w.\+]+$")
+
 # pylint: disable=W0613
 
 ## CORE
@@ -2805,3 +2807,48 @@ def mac_address(value,
                                             'address' % value)
 
     return value
+
+
+@disable_on_env
+def mimetype(value,
+             allow_empty = False,
+             **kwargs):
+    """Validate that ``value`` is a valid MIME-type.
+
+    :param value: The value to validate.
+    :type value: :class:`str <python:str>`
+
+    :param allow_empty: If ``True``, returns :obj:`None <python:None>` if
+      ``value`` is empty. If ``False``, raises a
+      :class:`EmptyValueError <validator_collection.errors.EmptyValueError>`
+      if ``value`` is empty. Defaults to ``False``.
+    :type allow_empty: :class:`bool <python:bool>`
+
+    :returns: ``value`` / :obj:`None <python:None>`
+    :rtype: :class:`str <python:str>` / :obj:`None <python:None>`
+
+    :raises EmptyValueError: if ``value`` is empty and ``allow_empty`` is ``False``
+    :raises CannotCoerceError: if ``value`` is not a valid string
+    :raises InvalidMimetypeError: if ``value`` is neither a valid MIME type nor empty
+      with ``allow_empty`` set to ``True``
+
+    """
+    if not value and not allow_empty:
+        raise errors.EmptyValueError('value (%s) was empty' % value)
+    elif not value:
+        return None
+
+    if not isinstance(value, basestring):
+        raise errors.CannotCoerceError('value must be a valid string, '
+                                       'was %s' % type(value))
+
+    value = value.lower().strip()
+
+    is_valid = MIME_TYPE_REGEX.fullmatch(value)
+
+    if not is_valid:
+        raise errors.InvalidMimeTypeError(
+            'value (%s) is not a valid MIME Type' % value
+        )
+
+    return value