add test coverage for python pacakge cataloger and update catalog interface

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

syft/pkg/egg_wheel_metadata.go

@@ -1,11 +0,0 @@
-package pkg
-
-// EggWheelMetadata represents all captured data for a python egg or wheel package.
-type EggWheelMetadata struct {
-	Name        string `json:"name" mapstruct:"Name"`
-	Version     string `json:"version" mapstruct:"Version"`
-	License     string `json:"license" mapstruct:"License"`
-	Author      string `json:"author" mapstruct:"Author"`
-	AuthorEmail string `json:"authorEmail" mapstruct:"Author-email"`
-	Platform    string `json:"platform" mapstruct:"Platform"`
-}

syft/pkg/metadata.go

@@ -8,7 +8,7 @@ const (
 	DpkgMetadataType           MetadataType = "dpkg-metadata"
 	GemMetadataType            MetadataType = "gem-metadata"
 	JavaMetadataType           MetadataType = "java-metadata"
-	NpmPackageJsonMetadataType MetadataType = "npm-package-json-metadata"
+	NpmPackageJSONMetadataType MetadataType = "npm-package-json-metadata"
 	RpmdbMetadataType          MetadataType = "rpmdb-metadata"
-	PythonEggWheelMetadataType MetadataType = "python-egg-wheel-metadata"
+	PythonPackageMetadataType  MetadataType = "python-package-metadata"
 )

syft/pkg/npm_metadata.go

@@ -1,7 +1,7 @@
 package pkg
 
-// NpmPackageJsonMetadata holds extra information that is used in pkg.Package
-type NpmPackageJsonMetadata struct {
+// NpmPackageJSONMetadata holds extra information that is used in pkg.Package
+type NpmPackageJSONMetadata struct {
 	Name        string   `mapstructure:"name" json:"name"`
 	Version     string   `mapstructure:"version" json:"version"`
 	Files       []string `mapstructure:"files" json:"files"`

syft/pkg/python_package_metadata.go

@@ -0,0 +1,23 @@
+package pkg
+
+type Digest struct {
+	Algorithm string `json:"algorithm"`
+	Value     string `json:"value"`
+}
+
+type PythonFileRecord struct {
+	Path   string `json:"path"`
+	Digest Digest `json:"digest"`
+	Size   string `json:"size"`
+}
+
+// PythonPackageMetadata represents all captured data for a python egg or wheel package.
+type PythonPackageMetadata struct {
+	Name        string             `json:"name" mapstruct:"Name"`
+	Version     string             `json:"version" mapstruct:"Version"`
+	License     string             `json:"license" mapstruct:"License"`
+	Author      string             `json:"author" mapstruct:"Author"`
+	AuthorEmail string             `json:"authorEmail" mapstruct:"Authoremail"`
+	Platform    string             `json:"platform" mapstruct:"Platform"`
+	Files       []PythonFileRecord `json:"files,omitempty"`
+}