feat(scanoss): Add exclusion pattern support to ScanOss

Implement a custom filter in the scanPath method that integrates with the
ScanOSS SDK to properly handle file exclusions based on patterns. The filter
converts paths appropriately to work with the context's exclude patterns.

Signed-off-by: Agustin Isasmendi <agustin.isasmendi@scanoss.com>

Author: isasmendiagus

plugins/scanners/scanoss/src/main/kotlin/ScanOss.kt

@@ -20,12 +20,15 @@
 package org.ossreviewtoolkit.plugins.scanners.scanoss
 
 import com.scanoss.Scanner
+import com.scanoss.filters.FilterConfig
 import com.scanoss.utils.JsonUtils
 import com.scanoss.utils.PackageDetails
 
 import java.io.File
 import java.time.Instant
 
+import org.apache.logging.log4j.kotlin.logger
+
 import org.ossreviewtoolkit.model.ScanSummary
 import org.ossreviewtoolkit.plugins.api.OrtPlugin
 import org.ossreviewtoolkit.plugins.api.PluginDescriptor
@@ -61,14 +64,39 @@ class ScanOss(
     override fun scanPath(path: File, context: ScanContext): ScanSummary {
         val startTime = Instant.now()
 
+        // basePath: The reference path used for creating relative paths.
+        val basePath = path.toPath()
+
+        val filterConfig = FilterConfig.builder()
+            .customFilter { currentPath ->
+                // currentPath: A Path object representing the file or directory being evaluated by the filter.
+                // This is provided by the Scanner and represents individual files/directories during traversal.
+                // It is an absolute path to a file or directory within the scan target.
+                try {
+                    // relativePath: The path of the current file relative to the base scan directory.
+                    // Example: If basePath is "/project" and currentPath is "/project/src/main/file.kt",
+                    // then relativePath becomes "src/main/file.kt".
+                    // This relative representation is what the exclusion patterns in context.excludes expect.
+                    val relativePath = basePath.relativize(currentPath).toString()
+                    val isExcluded = context.excludes?.isPathExcluded(relativePath) ?: false
+                    logger.debug("Path: $currentPath, relative: $relativePath, isExcluded: $isExcluded")
+                    isExcluded
+                } catch (e: IllegalArgumentException) {
+                    logger.warn("Error processing path $currentPath: ${e.message}")
+                    false
+                }
+            }
+            .build()
+
         val scanoss = Scanner.builder()
             .url(config.apiUrl.removeSuffix("/") + "/scan/direct")
             .apiKey(config.apiKey.value)
+            .filterConfig(filterConfig)
             .build()
 
         val rawResults: List<String> = when {
-            path.isFile -> listOf(scanoss.scanFile(path.absolutePath))
-            else -> scanoss.scanFolder(path.absolutePath)
+            path.isFile -> listOf(scanoss.scanFile(path.toString()))
+            else -> scanoss.scanFolder(path.toString())
         }
 
         val results = JsonUtils.toScanFileResults(rawResults)

plugins/scanners/scanoss/src/test/kotlin/ScanOssScannerDirectoryTest.kt

@@ -26,6 +26,7 @@ import io.kotest.core.spec.style.StringSpec
 import io.kotest.matchers.collections.containExactlyInAnyOrder
 import io.kotest.matchers.collections.shouldContainExactly
 import io.kotest.matchers.should
+import io.kotest.matchers.shouldBe
 
 import io.mockk.spyk
 
@@ -39,6 +40,9 @@ import org.ossreviewtoolkit.model.SnippetFinding
 import org.ossreviewtoolkit.model.TextLocation
 import org.ossreviewtoolkit.model.VcsInfo
 import org.ossreviewtoolkit.model.VcsType
+import org.ossreviewtoolkit.model.config.Excludes
+import org.ossreviewtoolkit.model.config.PathExclude
+import org.ossreviewtoolkit.model.config.PathExcludeReason
 import org.ossreviewtoolkit.plugins.api.Secret
 import org.ossreviewtoolkit.scanner.ScanContext
 import org.ossreviewtoolkit.utils.spdx.SpdxExpression
@@ -110,4 +114,27 @@ class ScanOssScannerDirectoryTest : StringSpec({
             )
         }
     }
+
+    "Scanner should exclude files matching the specified path pattern (*.kt files)" {
+        val pathExcludes = listOf(
+            PathExclude(
+                pattern = "**/*.kt",
+                reason = PathExcludeReason.BUILD_TOOL_OF,
+                comment = "Excluding .kt source files from scanning"
+            )
+        )
+
+        val summary = scanner.scanPath(
+            TEST_DIRECTORY_TO_SCAN,
+            ScanContext(
+                labels = emptyMap(),
+                packageType = PackageType.PACKAGE,
+                excludes = Excludes(paths = pathExcludes)
+            )
+        )
+
+        summary.licenseFindings.size shouldBe 0
+        summary.copyrightFindings.size shouldBe 0
+        summary.snippetFindings.size shouldBe 0
+    }
 })