Add license_file_references field for NuGet file-type licenses

Signed-off-by: Jayant Saxena <jayantmcom@gmail.com>

Author: Jayant-kernel

src/packagedcode/models.py

@@ -672,6 +672,12 @@ class PackageData(IdentifiablePackageData):
              'package manifest and extracted. This can be a string, a list or dict of '
              'strings possibly nested, as found originally in the manifest.')
 
+    license_file_references = List(
+        item_type=str,
+        label='license file references',
+        help='List of file paths referenced in the license statement.')
+
+
     notice_text = String(
         label='notice text',
         help='A notice text for this package.')

tests/packagedcode/data/nuget/file-license.nuspec

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<package xmlns="http://schemas.microsoft.com/packaging/2013/05/nuspec.xsd">
+  <metadata>
+    <id>TestPackage</id>
+    <version>1.0.0</version>
+    <license type="file">LICENSE.txt</license>
+    <authors>Test Author</authors>
+    <description>Test package with file-type license</description>
+  </metadata>
+</package>

tests/packagedcode/test_nuget.py

@@ -80,3 +80,10 @@ def test_parse_creates_package_with_license_file(self):
         package = list(package)[0]
         assert package.extracted_license_statement == 'LICENSE.txt'
         assert package.license_file_references == ['LICENSE.txt']
+
+    def test_parse_nuget_file_type_license(self):
+        test_file = self.get_test_loc('nuget/file-license.nuspec')
+        package = nuget.NugetNuspecHandler.parse(test_file)
+        package = list(package)[0]
+        assert package.license_file_references == ['LICENSE.txt']
+        assert package.extracted_license_statement == 'LICENSE.txt'