diff --git a/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciImageSpecResolution.kt b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciImageSpecResolution.kt
index ac3fa8ce..785c6d42 100644
--- a/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciImageSpecResolution.kt
+++ b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciImageSpecResolution.kt
@@ -1,8 +1,6 @@
 package io.github.sgtsilvio.gradle.oci.internal.resolution
 
-import io.github.sgtsilvio.gradle.oci.attributes.OCI_IMAGE_INDEX_PLATFORM_ATTRIBUTE
 import io.github.sgtsilvio.gradle.oci.attributes.OCI_IMAGE_REFERENCE_SPECS_ATTRIBUTE
-import io.github.sgtsilvio.gradle.oci.attributes.PLATFORM_ATTRIBUTE
 import io.github.sgtsilvio.gradle.oci.internal.gradle.VariantSelector
 import io.github.sgtsilvio.gradle.oci.internal.gradle.toVariantSelector
 import io.github.sgtsilvio.gradle.oci.metadata.DEFAULT_OCI_IMAGE_REFERENCE_SPEC
@@ -10,84 +8,13 @@ import io.github.sgtsilvio.gradle.oci.metadata.OciImageReferenceSpec
 import io.github.sgtsilvio.gradle.oci.metadata.toOciImageReferenceSpec
 import io.github.sgtsilvio.gradle.oci.platform.Platform
 import io.github.sgtsilvio.gradle.oci.platform.PlatformSelector
-import io.github.sgtsilvio.gradle.oci.platform.toPlatform
 import org.gradle.api.artifacts.result.ResolvedComponentResult
 import org.gradle.api.artifacts.result.ResolvedDependencyResult
 import org.gradle.api.artifacts.result.ResolvedVariantResult
 
-internal fun resolveOciVariantGraph(rootComponent: ResolvedComponentResult): List<OciVariantGraphRoot> {
-    // the first variant is the resolvable configuration, but only if it declares at least one dependency
-    val rootVariant = rootComponent.variants.firstOrNull() ?: return emptyList()
-    val variantToNode = HashMap<ResolvedVariantResult, OciVariantNode?>()
-    // rootNodesToDependencySelectors is linked to preserve the dependency order
-    val rootNodesToSelectors = LinkedHashMap<OciVariantNode, HashSet<VariantSelector>>()
-    for (dependency in rootComponent.getDependenciesForVariant(rootVariant)) {
-        if (dependency.isConstraint) continue
-        if (dependency !is ResolvedDependencyResult) throw ResolutionException()
-        val node = resolveOciVariantNode(dependency.selected, dependency.resolvedVariant, variantToNode)
-        rootNodesToSelectors.getOrPut(node) { HashSet() } += dependency.requested.toVariantSelector()
-    }
-    return rootNodesToSelectors.map { (node, selectors) -> OciVariantGraphRoot(node, selectors) }
-}
-
-private fun resolveOciVariantNode(
-    component: ResolvedComponentResult,
-    variant: ResolvedVariantResult,
-    variantToNode: HashMap<ResolvedVariantResult, OciVariantNode?>,
-): OciVariantNode {
-    if (variant in variantToNode) {
-        return variantToNode[variant] ?: throw IllegalStateException("cycle in dependencies graph")
-    }
-    variantToNode[variant] = null
-    // platformToDependenciesAndSupportedPlatforms is linked to preserve the platform order
-    val platformToDependenciesAndSupportedPlatforms =
-        LinkedHashMap<Platform?, Pair<ArrayList<OciVariantNode>, PlatformSet>>()
-    val platforms = variant.attributes.getAttribute(PLATFORM_ATTRIBUTE)?.decodePlatforms() ?: setOf(null)
-    for (platform in platforms) {
-        val supportedPlatforms = if (platform == null) PlatformSet(true) else PlatformSet(platform)
-        platformToDependenciesAndSupportedPlatforms[platform] = Pair(ArrayList(), supportedPlatforms)
-    }
-    for (dependency in component.getDependenciesForVariant(variant)) {
-        if (dependency.isConstraint) continue
-        if (dependency !is ResolvedDependencyResult) throw ResolutionException()
-        val dependencyPlatforms =
-            dependency.requested.attributes.getAttribute(OCI_IMAGE_INDEX_PLATFORM_ATTRIBUTE)?.decodePlatforms()
-                ?: platforms
-        val node = resolveOciVariantNode(dependency.selected, dependency.resolvedVariant, variantToNode)
-        for (dependencyPlatform in dependencyPlatforms) {
-            val (dependencies, supportedPlatforms) = platformToDependenciesAndSupportedPlatforms[dependencyPlatform]
-                ?: throw IllegalStateException("dependency can not be defined for more platforms than component") // TODO message
-            dependencies += node
-            supportedPlatforms.intersect(node.supportedPlatforms)
-        }
-    }
-    // platformToDependencies is linked to preserve the platform order
-    val platformToDependencies = LinkedHashMap<Platform?, List<OciVariantNode>>()
-    val platformSet = PlatformSet(false)
-    for ((platform, dependenciesAndSupportedPlatforms) in platformToDependenciesAndSupportedPlatforms) {
-        val (dependencies, supportedPlatforms) = dependenciesAndSupportedPlatforms
-        platformToDependencies[platform] = dependencies
-        platformSet.union(supportedPlatforms)
-    }
-    val node = OciVariantNode(variant, platformToDependencies, platformSet)
-    variantToNode[variant] = node
-    return node
-}
-
-internal class OciVariantNode(
-    val variant: ResolvedVariantResult,
-    val platformToDependencies: Map<Platform?, List<OciVariantNode>>,
-    val supportedPlatforms: PlatformSet,
-)
-
-internal class OciVariantGraphRoot(val node: OciVariantNode, val variantSelectors: Set<VariantSelector>)
-
-// return value is linked to preserve the platform order
-private fun String.decodePlatforms() = split(';').mapTo(LinkedHashSet()) { it.toPlatform() }
-
 // TODO new file from here?
 
-internal fun List<OciVariantGraphRoot>.selectPlatforms(
+internal fun OciVariantGraph.selectPlatforms(
     platformSelector: PlatformSelector?,
 ): List<Pair<OciVariantGraphRoot, Set<Platform>>> {
     val selectedPlatformsGraph = ArrayList<Pair<OciVariantGraphRoot, Set<Platform>>>(size)
diff --git a/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciVariantGraph.kt b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciVariantGraph.kt
new file mode 100644
index 00000000..19458357
--- /dev/null
+++ b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/resolution/OciVariantGraph.kt
@@ -0,0 +1,83 @@
+package io.github.sgtsilvio.gradle.oci.internal.resolution
+
+import io.github.sgtsilvio.gradle.oci.attributes.OCI_IMAGE_INDEX_PLATFORM_ATTRIBUTE
+import io.github.sgtsilvio.gradle.oci.attributes.PLATFORM_ATTRIBUTE
+import io.github.sgtsilvio.gradle.oci.internal.gradle.VariantSelector
+import io.github.sgtsilvio.gradle.oci.internal.gradle.toVariantSelector
+import io.github.sgtsilvio.gradle.oci.platform.Platform
+import io.github.sgtsilvio.gradle.oci.platform.toPlatform
+import org.gradle.api.artifacts.result.ResolvedComponentResult
+import org.gradle.api.artifacts.result.ResolvedDependencyResult
+import org.gradle.api.artifacts.result.ResolvedVariantResult
+
+internal typealias OciVariantGraph = List<OciVariantGraphRoot>
+
+internal class OciVariantGraphRoot(val node: OciVariantGraphNode, val variantSelectors: Set<VariantSelector>)
+
+internal class OciVariantGraphNode(
+    val variant: ResolvedVariantResult,
+    val platformToDependencies: Map<Platform?, List<OciVariantGraphNode>>,
+    val supportedPlatforms: PlatformSet,
+)
+
+internal fun resolveOciVariantGraph(rootComponent: ResolvedComponentResult): OciVariantGraph {
+    // the first variant is the resolvable configuration, but only if it declares at least one dependency
+    val rootVariant = rootComponent.variants.firstOrNull() ?: return emptyList()
+    val variantToNode = HashMap<ResolvedVariantResult, OciVariantGraphNode?>()
+    // rootNodesToDependencySelectors is linked to preserve the dependency order
+    val rootNodesToSelectors = LinkedHashMap<OciVariantGraphNode, HashSet<VariantSelector>>()
+    for (dependency in rootComponent.getDependenciesForVariant(rootVariant)) {
+        if (dependency.isConstraint) continue
+        if (dependency !is ResolvedDependencyResult) throw ResolutionException()
+        val node = resolveOciVariantGraphNode(dependency.selected, dependency.resolvedVariant, variantToNode)
+        rootNodesToSelectors.getOrPut(node) { HashSet() } += dependency.requested.toVariantSelector()
+    }
+    return rootNodesToSelectors.map { (node, selectors) -> OciVariantGraphRoot(node, selectors) }
+}
+
+private fun resolveOciVariantGraphNode(
+    component: ResolvedComponentResult,
+    variant: ResolvedVariantResult,
+    variantToNode: HashMap<ResolvedVariantResult, OciVariantGraphNode?>,
+): OciVariantGraphNode {
+    if (variant in variantToNode) {
+        return variantToNode[variant] ?: throw IllegalStateException("cycle in dependencies graph")
+    }
+    variantToNode[variant] = null
+    // platformToDependenciesAndSupportedPlatforms is linked to preserve the platform order
+    val platformToDependenciesAndSupportedPlatforms =
+        LinkedHashMap<Platform?, Pair<ArrayList<OciVariantGraphNode>, PlatformSet>>()
+    val platforms = variant.attributes.getAttribute(PLATFORM_ATTRIBUTE)?.decodePlatforms() ?: setOf(null)
+    for (platform in platforms) {
+        val supportedPlatforms = if (platform == null) PlatformSet(true) else PlatformSet(platform)
+        platformToDependenciesAndSupportedPlatforms[platform] = Pair(ArrayList(), supportedPlatforms)
+    }
+    for (dependency in component.getDependenciesForVariant(variant)) {
+        if (dependency.isConstraint) continue
+        if (dependency !is ResolvedDependencyResult) throw ResolutionException()
+        val dependencyPlatforms =
+            dependency.requested.attributes.getAttribute(OCI_IMAGE_INDEX_PLATFORM_ATTRIBUTE)?.decodePlatforms()
+                ?: platforms
+        val node = resolveOciVariantGraphNode(dependency.selected, dependency.resolvedVariant, variantToNode)
+        for (dependencyPlatform in dependencyPlatforms) {
+            val (dependencies, supportedPlatforms) = platformToDependenciesAndSupportedPlatforms[dependencyPlatform]
+                ?: throw IllegalStateException("dependency can not be defined for more platforms than component") // TODO message
+            dependencies += node
+            supportedPlatforms.intersect(node.supportedPlatforms)
+        }
+    }
+    // platformToDependencies is linked to preserve the platform order
+    val platformToDependencies = LinkedHashMap<Platform?, List<OciVariantGraphNode>>()
+    val platformSet = PlatformSet(false)
+    for ((platform, dependenciesAndSupportedPlatforms) in platformToDependenciesAndSupportedPlatforms) {
+        val (dependencies, supportedPlatforms) = dependenciesAndSupportedPlatforms
+        platformToDependencies[platform] = dependencies
+        platformSet.union(supportedPlatforms)
+    }
+    val node = OciVariantGraphNode(variant, platformToDependencies, platformSet)
+    variantToNode[variant] = node
+    return node
+}
+
+// return value is linked to preserve the platform order
+private fun String.decodePlatforms() = split(';').mapTo(LinkedHashSet()) { it.toPlatform() }