feat(dsl): allow specifying Kotlin step's condition in Kotlin (#1410)

It creates a synthetic step prior to running the actual step where the
condition is specified. Lets the user avoid crafting complicated
string-based GitHub expressions, in favor of a type-safe Kotlin code
returning a boolean.

Author: krzema12

github-workflows-kt/api/github-workflows-kt.api

@@ -1885,9 +1885,9 @@ public final class io/github/typesafegithub/workflows/dsl/JobBuilder : io/github
 	public final fun getTimeoutMinutes ()Ljava/lang/Integer;
 	public fun get_customArguments ()Ljava/util/Map;
 	public final fun run ([Lkotlin/Unit;Ljava/lang/String;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;Ljava/lang/Integer;Lio/github/typesafegithub/workflows/domain/Shell;Ljava/lang/String;Ljava/util/Map;)Lio/github/typesafegithub/workflows/domain/CommandStep;
-	public final fun run ([Lkotlin/Unit;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;Ljava/lang/Integer;Lio/github/typesafegithub/workflows/domain/Shell;Ljava/lang/String;Ljava/util/Map;Lkotlin/jvm/functions/Function1;)Lio/github/typesafegithub/workflows/domain/KotlinLogicStep;
+	public final fun run ([Lkotlin/Unit;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/Boolean;Ljava/lang/Integer;Lio/github/typesafegithub/workflows/domain/Shell;Ljava/lang/String;Ljava/util/Map;Lkotlin/jvm/functions/Function1;)Lio/github/typesafegithub/workflows/domain/KotlinLogicStep;
 	public static synthetic fun run$default (Lio/github/typesafegithub/workflows/dsl/JobBuilder;[Lkotlin/Unit;Ljava/lang/String;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;Ljava/lang/Integer;Lio/github/typesafegithub/workflows/domain/Shell;Ljava/lang/String;Ljava/util/Map;ILjava/lang/Object;)Lio/github/typesafegithub/workflows/domain/CommandStep;
-	public static synthetic fun run$default (Lio/github/typesafegithub/workflows/dsl/JobBuilder;[Lkotlin/Unit;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;Ljava/lang/Integer;Lio/github/typesafegithub/workflows/domain/Shell;Ljava/lang/String;Ljava/util/Map;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lio/github/typesafegithub/workflows/domain/KotlinLogicStep;
+	public static synthetic fun run$default (Lio/github/typesafegithub/workflows/dsl/JobBuilder;[Lkotlin/Unit;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/Boolean;Ljava/lang/Integer;Lio/github/typesafegithub/workflows/domain/Shell;Ljava/lang/String;Ljava/util/Map;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lio/github/typesafegithub/workflows/domain/KotlinLogicStep;
 	public final fun uses ([Lkotlin/Unit;Lio/github/typesafegithub/workflows/domain/actions/Action;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;Ljava/lang/Integer;Ljava/util/Map;)Lio/github/typesafegithub/workflows/domain/ActionStep;
 	public static synthetic fun uses$default (Lio/github/typesafegithub/workflows/dsl/JobBuilder;[Lkotlin/Unit;Lio/github/typesafegithub/workflows/domain/actions/Action;Ljava/lang/String;Ljava/util/LinkedHashMap;Ljava/lang/String;Ljava/lang/String;Ljava/lang/Boolean;Ljava/lang/Integer;Ljava/util/Map;ILjava/lang/Object;)Lio/github/typesafegithub/workflows/domain/ActionStep;
 }

github-workflows-kt/src/main/kotlin/io/github/typesafegithub/workflows/dsl/JobBuilder.kt

@@ -15,6 +15,7 @@ import io.github.typesafegithub.workflows.domain.RunnerType
 import io.github.typesafegithub.workflows.domain.Shell
 import io.github.typesafegithub.workflows.domain.actions.Action
 import io.github.typesafegithub.workflows.domain.contexts.Contexts
+import io.github.typesafegithub.workflows.dsl.expressions.expr
 import kotlinx.serialization.Contextual
 import kotlin.io.path.name
 
@@ -104,6 +105,7 @@ public class JobBuilder<OUTPUT : JobOutputs>(
         @SuppressWarnings("FunctionParameterNaming")
         `if`: String? = null,
         condition: String? = null,
+        ifKotlin: (Contexts.() -> Boolean)? = null,
         continueOnError: Boolean? = null,
         timeoutMinutes: Int? = null,
         shell: Shell? = null,
@@ -112,17 +114,25 @@ public class JobBuilder<OUTPUT : JobOutputs>(
         _customArguments: Map<String, @Contextual Any> = mapOf(),
         logic: Contexts.() -> Unit,
     ): KotlinLogicStep {
-        require(!(`if` != null && condition != null)) {
-            "Either 'if' or 'condition' have to be set, not both!"
+        require(listOfNotNull(`if`, condition, ifKotlin).size <= 1) {
+            "Only one of 'if', 'condition' or `ifKotlin` can be set!"
         }
         require(job.steps.filterIsInstance<ActionStep<*>>().any { "/checkout@" in it.action.usesString }) {
             "Please check out the code prior to using Kotlin-based 'run' block!"
         }
         val sourceFile =
             workflowBuilder.workflow.sourceFile
                 ?: throw IllegalArgumentException("sourceFile needs to be set when using Kotlin-based 'run' block!")
-        val id = "step-${job.steps.size}"
+        val evaluationResultOutput = "evaluation-result"
 
+        val conditionCheckingStep =
+            ifKotlin?.let {
+                run {
+                    outputs[evaluationResultOutput] = ifKotlin().toString()
+                }
+            }
+
+        val id = "step-${job.steps.size}"
         val newStep =
             KotlinLogicStep(
                 id = id,
@@ -133,7 +143,10 @@ public class JobBuilder<OUTPUT : JobOutputs>(
                 command = "GHWKT_RUN_STEP='${this.id}:$id' '.github/workflows/${sourceFile.name}'",
                 logic = logic,
                 env = LinkedHashMap(env.toMap() + mapOf("GHWKT_GITHUB_CONTEXT_JSON" to "${'$'}{{ toJSON(github) }}")),
-                condition = `if` ?: condition,
+                condition =
+                    conditionCheckingStep?.let {
+                        expr { "steps.${conditionCheckingStep.id}.outputs.$evaluationResultOutput" }
+                    } ?: `if` ?: condition,
                 continueOnError = continueOnError,
                 timeoutMinutes = timeoutMinutes,
                 shell = shell,