Cover custom MetadataKey; align factory parameter naming

.github/workflows/build-on-ubuntu.yml

@@ -87,7 +87,7 @@ jobs:
       # there anyway).
       - name: Upload code coverage report
         if: steps.codecov.outputs.available == 'true' || github.event_name == 'push'
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v7
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           fail_ci_if_error: true

buildSrc/src/main/kotlin/io/spine/dependency/local/Compiler.kt

@@ -27,6 +27,8 @@
 package io.spine.dependency.local
 
 import io.spine.dependency.Dependency
+import io.spine.dependency.local.Compiler.DF_VERSION_ENV
+import io.spine.dependency.local.Compiler.VERSION_ENV
 
 /**
  * Dependencies on the Spine Compiler modules.
@@ -72,7 +74,7 @@ object Compiler : Dependency() {
      * The version of the Compiler dependencies.
      */
     override val version: String
-    private const val fallbackVersion = "2.0.0-SNAPSHOT.056"
+    private const val fallbackVersion = "2.0.0-SNAPSHOT.057"
 
     /**
      * The distinct version of the Compiler used by other build tools.
@@ -81,7 +83,7 @@ object Compiler : Dependency() {
      * transitive dependencies, this is the version used to build the project itself.
      */
     val dogfoodingVersion: String
-    private const val fallbackDfVersion = "2.0.0-SNAPSHOT.056"
+    private const val fallbackDfVersion = "2.0.0-SNAPSHOT.057"
 
     /**
      * The artifact for the Compiler Gradle plugin.

buildSrc/src/main/kotlin/io/spine/dependency/local/Logging.kt

@@ -33,7 +33,7 @@ package io.spine.dependency.local
  */
 @Suppress("ConstPropertyName", "unused")
 object Logging {
-    const val version = "2.0.0-SNAPSHOT.417"
+    const val version = "2.0.0-SNAPSHOT.419"
     const val group = Spine.group
 
     const val loggingArtifact = "spine-logging"

buildSrc/src/main/kotlin/io/spine/gradle/kotlin/KotlinConfig.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,20 +55,26 @@ fun KotlinJvmProjectExtension.applyJvmToolchain(version: String) =
  */
 @Suppress("unused")
 fun KotlinCommonCompilerOptions.setFreeCompilerArgs() {
+    val optIns = mutableListOf(
+        "kotlin.contracts.ExperimentalContracts",
+        "kotlin.ExperimentalUnsignedTypes",
+        "kotlin.ExperimentalStdlibApi",
+        "kotlin.experimental.ExperimentalTypeInference",
+    )
     if (this is KotlinJvmCompilerOptions) {
         jvmDefault.set(JvmDefaultMode.NO_COMPATIBILITY)
+        // `kotlin.io.path` ships only in the JVM standard library, so for common
+        // and Native compilations this opt-in marker is unresolved and the compiler
+        // warns about it. Scope it to JVM compilations; multiplatform common and
+        // Native code cannot use the API anyway.
+        optIns.add("kotlin.io.path.ExperimentalPathApi")
     }
     freeCompilerArgs.addAll(
         listOf(
             "-Xskip-prerelease-check",
             "-Xexpect-actual-classes",
             "-Xcontext-parameters",
-            "-opt-in=" +
-                    "kotlin.contracts.ExperimentalContracts," +
-                    "kotlin.io.path.ExperimentalPathApi," +
-                    "kotlin.ExperimentalUnsignedTypes," +
-                    "kotlin.ExperimentalStdlibApi," +
-                    "kotlin.experimental.ExperimentalTypeInference",
+            "-opt-in=" + optIns.joinToString(separator = ","),
         )
     )
 }

contexts/context-tests/src/testFixtures/kotlin/io/spine/logging/context/AbstractContextDataProviderSpec.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -87,6 +87,15 @@ abstract class AbstractContextDataProviderSpec {
     private companion object {
         private val FOO = MetadataKey.single<String>("foo")
         private val BAR = MetadataKey.repeated<String>("bar")
+
+        /**
+         * A custom [MetadataKey] created by subclassing rather than via the factory
+         * functions, reproducing the scenario from
+         * [issue #70](https://github.com/SpineEventEngine/logging/issues/70).
+         */
+        private val CUSTOM =
+            object : MetadataKey<String>("custom", String::class, canRepeat = false) {}
+
         private val SUB_TASK = ScopeType.create("sub task")
         private val BATCH_JOB = ScopeType.create("batch job")
     }
@@ -157,6 +166,30 @@ abstract class AbstractContextDataProviderSpec {
             checkCallbackWasExecuted()
         }
 
+        /**
+         * Verifies that a custom [MetadataKey] — created by subclassing rather than via
+         * the factory functions — can be attached to a context and is delivered to the
+         * context metadata.
+         *
+         * This is a regression test for
+         * [issue #70](https://github.com/SpineEventEngine/logging/issues/70), where
+         * passing a custom key to `withMetadata` used to throw a `ClassCastException`
+         * on the JVM.
+         */
+        @Test
+        fun `with a custom metadata key`() {
+            val value = "custom-value"
+            contextMetadata.shouldBeEmpty()
+            context.newContext()
+                .withMetadata(CUSTOM, value)
+                .call {
+                    contextMetadata.shouldUniquelyContain(CUSTOM, value)
+                    markCallbackExecuted()
+                }
+            contextMetadata.shouldBeEmpty()
+            checkCallbackWasExecuted()
+        }
+
         @Test
         fun `with a log level map`() {
             val defaultLevel = TLevel.FINE