fix(gradle-plugin): Do not fail with NPE when dependency POMs are mis…

…sing

Sometimes, POM cannot be resolved by ORT for one reason or another. When
this happens, the analysis finishes early, omitting dependencies that
have POMs but were unlucky to be listed after the POMless one.

The fix itself is simple: instead of requiring a non-null value in POMs
map (through `getValue`), add a warning and leave the fields empty when
the returned POM is null.

For example, ORT fails scanning [1] and [2] without the patch due to
Gradle IntelliJ Plugin [3] injecting dependencies without POMs.

[1] https://github.com/JetBrains/Grammar-Kit
[2] https://github.com/JetBrains/ideavim
[3] https://github.com/JetBrains/intellij-platform-gradle-plugin

Signed-off-by: Igor Brovtsin <[email protected]>

plugins/package-managers/gradle-plugin/src/main/kotlin/OrtModelBuilder.kt

@@ -198,7 +198,13 @@ internal class OrtModelBuilder : ToolingModelBuilder {
                                 null
                             }
 
-                            val modelBuildingResult = poms.getValue(id.toString())
+                            val modelBuildingResult = poms[id.toString()]
+                            if (modelBuildingResult == null && id !in visitedDependencies) {
+                                val message = "No POM found for $id"
+                                logger.warn(message)
+                                warnings += message
+                            }
+
                             val dependencies = if (id in visitedDependencies) {
                                 // Cut the graph on cyclic dependencies.
                                 emptyList()
@@ -212,18 +218,20 @@ internal class OrtModelBuilder : ToolingModelBuilder {
                                 artifactId = id.module,
                                 version = id.version,
                                 classifier = "",
-                                extension = modelBuildingResult.effectiveModel.packaging,
+                                extension = modelBuildingResult?.effectiveModel?.packaging.orEmpty(),
                                 dependencies = dependencies,
                                 error = null,
                                 warning = null,
                                 pomFile = pomFile,
-                                mavenModel = OrtMavenModelImpl(
-                                    licenses = modelBuildingResult.effectiveModel.collectLicenses(),
-                                    authors = modelBuildingResult.effectiveModel.collectAuthors(),
-                                    description = modelBuildingResult.effectiveModel.description.orEmpty(),
-                                    homepageUrl = modelBuildingResult.effectiveModel.url.orEmpty(),
-                                    vcs = modelBuildingResult.getVcsModel()
-                                ),
+                                mavenModel = modelBuildingResult?.run {
+                                    OrtMavenModelImpl(
+                                        licenses = effectiveModel.collectLicenses(),
+                                        authors = effectiveModel.collectAuthors(),
+                                        description = effectiveModel.description.orEmpty(),
+                                        homepageUrl = effectiveModel.url.orEmpty(),
+                                        vcs = getVcsModel()
+                                    )
+                                },
                                 localPath = null
                             )
                         }