proper enums

fixes #442
part of #446

BREAKING CHANGE

Signed-off-by: Jan Kowalleck <jan.kowalleck@gmail.com>

cyclonedx/output/__init__.py

@@ -19,10 +19,10 @@
 and according to different versions of the CycloneDX schema standard.
 """
 
-import importlib
 import os
 from abc import ABC, abstractmethod
-from typing import Iterable, Union, cast
+from importlib import import_module
+from typing import Iterable, Optional, Type, Union
 
 from ..model.bom import Bom
 from ..model.component import Component
@@ -46,7 +46,12 @@ def _chained_components(self, container: Union[Bom, Component]) -> Iterable[Comp
     @property
     @abstractmethod
     def schema_version(self) -> SchemaVersion:
-        pass
+        ...
+
+    @property
+    @abstractmethod
+    def output_format(self) -> OutputFormat:
+        ...
 
     @property
     def generated(self) -> bool:
@@ -64,28 +69,23 @@ def set_bom(self, bom: Bom) -> None:
 
     @abstractmethod
     def generate(self, force_regeneration: bool = False) -> None:
-        pass
+        ...
 
     @abstractmethod
     def output_as_string(self) -> str:
-        pass
+        ...
 
     def output_to_file(self, filename: str, allow_overwrite: bool = False) -> None:
         # Check directory writable
         output_filename = os.path.realpath(filename)
         output_directory = os.path.dirname(output_filename)
-
         if not os.access(output_directory, os.W_OK):
             raise PermissionError(output_directory)
-
         if os.path.exists(output_filename) and not allow_overwrite:
             raise FileExistsError(output_filename)
-
         with open(output_filename, mode='wb') as f_out:
             f_out.write(self.output_as_string().encode('utf-8'))
 
-        f_out.close()
-
 
 def get_instance(bom: Bom, output_format: OutputFormat = OutputFormat.XML,
                  schema_version: SchemaVersion = LATEST_SUPPORTED_SCHEMA_VERSION) -> BaseOutput:
@@ -99,10 +99,16 @@ def get_instance(bom: Bom, output_format: OutputFormat = OutputFormat.XML,
     :param schema_version: SchemaVersion
     :return:
     """
+    # all exceptions are undocumented, as they are pure functional, and should be prevented by correct typing...
+    if not isinstance(output_format, OutputFormat):
+        raise TypeError(f"unexpected output_format: {output_format!r}")
+    if not isinstance(schema_version, SchemaVersion):
+        raise TypeError(f"unexpected schema_version: {schema_version!r}")
     try:
-        module = importlib.import_module(f"cyclonedx.output.{output_format.value.lower()}")
-        output_klass = getattr(module, f"{output_format.value}{schema_version.value}")
-    except (ImportError, AttributeError) as e:
-        raise ValueError(f"Unknown format {output_format.value.lower()!r}: {e}") from None
-
-    return cast(BaseOutput, output_klass(bom=bom))
+        module = import_module(f'.{output_format.name.lower()}', __package__)
+    except ImportError as error:  # pragma: no cover
+        raise ValueError(f'Unknown output_format: {output_format.name}') from error
+    output_klass: Optional[Type[BaseOutput]] = module.BY_SCHEMA_VERSION.get(schema_version, None)
+    if output_klass is None:  # pragma: no cover
+        raise ValueError(f'Unknown {output_format.name}/schema_version: {schema_version.name}')
+    return output_klass(bom=bom)

cyclonedx/output/json.py

@@ -19,11 +19,11 @@
 
 import json
 from abc import abstractmethod
-from typing import Optional
+from typing import Dict, Optional, Type
 
 from ..exception.output import FormatNotSupportedException
 from ..model.bom import Bom
-from ..schema import SchemaVersion
+from ..schema import OutputFormat, SchemaVersion
 from ..schema.schema import (
     SCHEMA_VERSIONS,
     BaseSchemaVersion,
@@ -46,6 +46,10 @@ def __init__(self, bom: Bom) -> None:
     def schema_version(self) -> SchemaVersion:
         return self.schema_version_enum
 
+    @property
+    def output_format(self) -> OutputFormat:
+        return OutputFormat.JSON
+
     def generate(self, force_regeneration: bool = False) -> None:
         # New Way
         schema_uri: Optional[str] = self._get_schema_uri()
@@ -58,7 +62,7 @@ def generate(self, force_regeneration: bool = False) -> None:
             'bomFormat': 'CycloneDX',
             'specVersion': self.schema_version.to_version()
         }
-        _view = SCHEMA_VERSIONS.get(self.get_schema_version())
+        _view = SCHEMA_VERSIONS.get(self.schema_version_enum)
         if self.generated and force_regeneration:
             self.get_bom().validate()
             bom_json = json.loads(self.get_bom().as_json(view_=_view))  # type: ignore
@@ -113,3 +117,12 @@ class JsonV1Dot4(Json, SchemaVersion1Dot4):
 
     def _get_schema_uri(self) -> Optional[str]:
         return 'http://cyclonedx.org/schema/bom-1.4.schema.json'
+
+
+BY_SCHEMA_VERSION: Dict[SchemaVersion, Type[Json]] = {
+    SchemaVersion.V1_4: JsonV1Dot4,  # type:ignore[type-abstract]
+    SchemaVersion.V1_3: JsonV1Dot3,  # type:ignore[type-abstract]
+    SchemaVersion.V1_2: JsonV1Dot2,  # type:ignore[type-abstract]
+    SchemaVersion.V1_1: JsonV1Dot1,  # type:ignore[type-abstract]
+    SchemaVersion.V1_0: JsonV1Dot0,  # type:ignore[type-abstract]
+}

cyclonedx/output/xml.py

@@ -1,5 +1,22 @@
 # encoding: utf-8
 
+from typing import Dict, Optional, Type
+from xml.etree import ElementTree
+
+from ..exception.output import BomGenerationErrorException
+from ..model.bom import Bom
+from ..schema import OutputFormat, SchemaVersion
+from ..schema.schema import (
+    SCHEMA_VERSIONS,
+    BaseSchemaVersion,
+    SchemaVersion1Dot0,
+    SchemaVersion1Dot1,
+    SchemaVersion1Dot2,
+    SchemaVersion1Dot3,
+    SchemaVersion1Dot4,
+)
+from . import BaseOutput
+
 # This file is part of CycloneDX Python Lib
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -17,25 +34,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (c) OWASP Foundation. All Rights Reserved.
 
-from typing import Optional
-from xml.etree import ElementTree
-
-from ..exception.output import BomGenerationErrorException
-from ..model.bom import Bom
-from ..schema import SchemaVersion
-from ..schema.schema import (
-    SCHEMA_VERSIONS,
-    BaseSchemaVersion,
-    SchemaVersion1Dot0,
-    SchemaVersion1Dot1,
-    SchemaVersion1Dot2,
-    SchemaVersion1Dot3,
-    SchemaVersion1Dot4,
-)
-from . import BaseOutput
-
 
-class Xml(BaseOutput, BaseSchemaVersion):
+class Xml(BaseSchemaVersion, BaseOutput):
     XML_VERSION_DECLARATION: str = '<?xml version="1.0" encoding="UTF-8"?>'
 
     def __init__(self, bom: Bom) -> None:
@@ -46,9 +46,13 @@ def __init__(self, bom: Bom) -> None:
     def schema_version(self) -> SchemaVersion:
         return self.schema_version_enum
 
+    @property
+    def output_format(self) -> OutputFormat:
+        return OutputFormat.XML
+
     def generate(self, force_regeneration: bool = False) -> None:
         # New way
-        _view = SCHEMA_VERSIONS.get(self.get_schema_version())
+        _view = SCHEMA_VERSIONS[self.schema_version_enum]
         if self.generated and force_regeneration:
             self.get_bom().validate()
             self._root_bom_element = self.get_bom().as_xml(  # type: ignore
@@ -97,3 +101,12 @@ class XmlV1Dot3(Xml, SchemaVersion1Dot3):
 
 class XmlV1Dot4(Xml, SchemaVersion1Dot4):
     pass
+
+
+BY_SCHEMA_VERSION: Dict[SchemaVersion, Type[Xml]] = {
+    SchemaVersion.V1_4: XmlV1Dot4,  # type:ignore[type-abstract]
+    SchemaVersion.V1_3: XmlV1Dot3,  # type:ignore[type-abstract]
+    SchemaVersion.V1_2: XmlV1Dot2,  # type:ignore[type-abstract]
+    SchemaVersion.V1_1: XmlV1Dot1,  # type:ignore[type-abstract]
+    SchemaVersion.V1_0: XmlV1Dot0,  # type:ignore[type-abstract]
+}

cyclonedx/schema/__init__.py

@@ -14,26 +14,73 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-from enum import Enum
+from enum import Enum, auto, unique
 
 
-class OutputFormat(str, Enum):
-    JSON: str = 'Json'
-    XML: str = 'Xml'
+@unique
+class OutputFormat(Enum):
+    """Output formats.
 
+    Do not rely on the actual/literal values, just use enum cases.
+    """
+    JSON = auto()
+    XML = auto()
 
-class SchemaVersion(str, Enum):
-    V1_0: str = 'V1Dot0'
-    V1_1: str = 'V1Dot1'
-    V1_2: str = 'V1Dot2'
-    V1_3: str = 'V1Dot3'
-    V1_4: str = 'V1Dot4'
+
+@unique
+class SchemaVersion(Enum):
+    """
+    Schema version.
+
+    Cases are hashable.
+    Cases are comparable(!=,>=,>,==,<,<=)
+
+    Do not rely on the actual/literal values, just use enum cases.
+    """
+    V1_4 = (1, 4)
+    V1_3 = (1, 3)
+    V1_2 = (1, 2)
+    V1_1 = (1, 1)
+    V1_0 = (1, 0)
+
+    @classmethod
+    def from_version(cls, version: str) -> 'SchemaVersion':
+        """Return instance from  a version string - e.g. `1.4`"""
+        return cls(tuple(map(int, version.split('.')))[:2])
 
     def to_version(self) -> str:
-        """
-        Return as a version string - e.g. `1.4`
+        """Return as a version string - e.g. `1.4`"""
+        return '.'.join(map(str, self.value))
+
+    def __ne__(self, other: object) -> bool:
+        return self.value != other.value \
+            if isinstance(other, self.__class__) \
+            else NotImplemented  # type:ignore[return-value]
+
+    def __lt__(self, other: object) -> bool:
+        return self.value < other.value \
+            if isinstance(other, self.__class__) \
+            else NotImplemented  # type:ignore[return-value]
+
+    def __le__(self, other: object) -> bool:
+        return self.value <= other.value \
+            if isinstance(other, self.__class__) \
+            else NotImplemented  # type:ignore[return-value]
+
+    def __eq__(self, other: object) -> bool:
+        return self.value == other.value \
+            if isinstance(other, self.__class__) \
+            else NotImplemented  # type:ignore[return-value]
+
+    def __ge__(self, other: object) -> bool:
+        return self.value >= other.value \
+            if isinstance(other, self.__class__) \
+            else NotImplemented  # type:ignore[return-value]
+
+    def __gt__(self, other: object) -> bool:
+        return self.value > other.value \
+            if isinstance(other, self.__class__) \
+            else NotImplemented  # type:ignore[return-value]
 
-        Returns:
-            `str` version
-        """
-        return f'{self.value[1]}.{self.value[5]}'
+    def __hash__(self) -> int:
+        return hash(self.name)

cyclonedx/schema/schema.py

@@ -18,6 +18,7 @@
 # Copyright (c) OWASP Foundation. All Rights Reserved.
 
 from abc import ABC, abstractmethod
+from typing import Dict, Type
 
 from serializable import ViewType
 
@@ -29,7 +30,7 @@ class BaseSchemaVersion(ABC, ViewType):
     @property
     @abstractmethod
     def schema_version_enum(self) -> SchemaVersion:
-        pass
+        ...
 
     def get_schema_version(self) -> str:
         return self.schema_version_enum.to_version()
@@ -70,10 +71,10 @@ def schema_version_enum(self) -> SchemaVersion:
         return SchemaVersion.V1_0
 
 
-SCHEMA_VERSIONS = {
-    '1.0': SchemaVersion1Dot0,
-    '1.1': SchemaVersion1Dot1,
-    '1.2': SchemaVersion1Dot2,
-    '1.3': SchemaVersion1Dot3,
-    '1.4': SchemaVersion1Dot4
+SCHEMA_VERSIONS: Dict[SchemaVersion, Type[BaseSchemaVersion]] = {
+    SchemaVersion.V1_4: SchemaVersion1Dot4,  # type:ignore[type-abstract]
+    SchemaVersion.V1_3: SchemaVersion1Dot3,  # type:ignore[type-abstract]
+    SchemaVersion.V1_2: SchemaVersion1Dot2,  # type:ignore[type-abstract]
+    SchemaVersion.V1_1: SchemaVersion1Dot1,  # type:ignore[type-abstract]
+    SchemaVersion.V1_0: SchemaVersion1Dot0,  # type:ignore[type-abstract]
 }

tests/test_output.py

@@ -0,0 +1,53 @@
+# encoding: utf-8
+
+# This file is part of CycloneDX Python Lib
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) OWASP Foundation. All Rights Reserved.
+
+
+from itertools import product
+from typing import Tuple
+from unittest import TestCase
+from unittest.mock import Mock
+
+from ddt import data, ddt, named_data, unpack
+
+from cyclonedx.model.bom import Bom
+from cyclonedx.output import get_instance as get_outputter
+from cyclonedx.schema import OutputFormat, SchemaVersion
+
+
+@ddt
+class Test(TestCase):
+
+    @named_data(*([f'{x[0].name} {x[1].name}', *x] for x in product(OutputFormat, SchemaVersion)))
+    @unpack
+    def test_get_instance_expected(self, of: OutputFormat, sv: SchemaVersion) -> None:
+        bom = Mock(spec=Bom)
+        outputter = get_outputter(bom, of, sv)
+        self.assertIs(outputter.get_bom(), bom)
+        self.assertIs(outputter.output_format, of)
+        self.assertIs(outputter.schema_version, sv)
+
+    @data(
+        *((of, 'foo', (TypeError, "unexpected schema_version: 'foo'")) for of in OutputFormat),
+        *(('foo', sv, (TypeError, "unexpected output_format: 'foo'")) for sv in SchemaVersion),
+    )
+    @unpack
+    def test_get_instance_fails(self, of: OutputFormat, sv: SchemaVersion, raisesRegex: Tuple) -> None:
+        bom = Mock(spec=Bom)
+        with self.assertRaisesRegexp(*raisesRegex):
+            get_outputter(bom, of, sv)