feat(nuget)!: Split the (technology) namespace from the name

Use up to two namespace nodes from the name as defined at [1] as the
package namespace.

[1]: https://learn.microsoft.com/en-us/dotnet/standard/design-guidelines/names-of-namespaces

Signed-off-by: Sebastian Schuberth <[email protected]>

plugins/package-managers/nuget/src/main/kotlin/utils/NuGetInspector.kt

@@ -197,6 +197,13 @@ private fun List<NuGetInspector.PackageData>.toPackageReferences(): Set<PackageR
         )
     }
 
+internal fun getIdentifierWithNamespace(name: String, version: String): Identifier {
+    val namespace = name.split('.', limit = 3).toMutableList()
+    val nameWithoutNamespace = namespace.removeLast()
+    val namespaceWithoutName = namespace.joinToString(".")
+    return Identifier(type = TYPE, namespace = namespaceWithoutName, name = nameWithoutNamespace, version = version)
+}
+
 internal fun Collection<NuGetInspector.PackageData>.toOrtPackages(): Set<Package> =
     groupBy { "${it.name}:${it.version}" }.mapTo(mutableSetOf()) { (_, packages) ->
         val pkg = packages.first()
@@ -206,12 +213,16 @@ internal fun Collection<NuGetInspector.PackageData>.toOrtPackages(): Set<Package
                 (sha512 ?: sha256 ?: sha1 ?: md5 ?: "").lowercase()
             )
 
-        val id = Identifier(
-            type = TYPE,
-            namespace = pkg.namespace.orEmpty(),
-            name = pkg.name,
-            version = pkg.version.orEmpty()
-        )
+        val id = if (pkg.namespace.isNullOrEmpty()) {
+            getIdentifierWithNamespace(pkg.name, pkg.version.orEmpty())
+        } else {
+            Identifier(
+                type = TYPE,
+                namespace = pkg.namespace,
+                name = pkg.name,
+                version = pkg.version.orEmpty()
+            )
+        }
 
         val declaredLicenses = mutableSetOf<String>()
         val pkgDeclaredLicense = pkg.declaredLicense.orEmpty()

plugins/package-managers/nuget/src/test/kotlin/utils/NuGetInspectorTest.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2020 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
+ *
+ * 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
+ *
+ *     https://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
+ * License-Filename: LICENSE
+ */
+
+package org.ossreviewtoolkit.plugins.packagemanagers.nuget.utils
+
+import io.kotest.assertions.assertSoftly
+import io.kotest.core.spec.style.WordSpec
+import io.kotest.matchers.shouldBe
+
+import org.ossreviewtoolkit.model.Identifier
+
+class NuGetInspectorTest : WordSpec({
+    "getIdentifierWithNamespace()" should {
+        "split the namespace from the name" {
+            assertSoftly {
+                getIdentifierWithNamespace("SharpCompress", "0.23.0") shouldBe
+                    Identifier("NuGet::SharpCompress:0.23.0")
+                getIdentifierWithNamespace("System.IO", "4.1.0") shouldBe
+                    Identifier("NuGet:System:IO:4.1.0")
+                getIdentifierWithNamespace("System.IO.Compression", "4.3.0") shouldBe
+                    Identifier("NuGet:System.IO:Compression:4.3.0")
+                getIdentifierWithNamespace("System.IO.Compression.ZipFile", "4.0.1") shouldBe
+                    Identifier("NuGet:System.IO:Compression.ZipFile:4.0.1")
+            }
+        }
+    }
+})