fix(model-api): add children eagerly to concepts for builtin languages

Previously, the child links were only added lazily by delegates or not at all.
This resulted in returning incomplete lists of child links.

Author: Oleksandr Dzhychko

model-api/src/commonMain/kotlin/org/modelix/model/api/BuiltinLanguages.kt

@@ -16,8 +16,6 @@
 
 package org.modelix.model.api
 
-import kotlin.reflect.KProperty
-
 /**
  * TODO if you add a new Concept to a language, do not forget to add it to the language's included concepts field.
  * Otherwise the concept will not be eagerly added to the Language, when registering the language in the ILanguageRegistry.
@@ -43,8 +41,13 @@ object BuiltinLanguages {
                 uid = "ceab5195-25ea-4f22-9b92-103b95ca8c0c/1133920641626/1193676396447",
             ).also(this::addProperty)
 
-            val smodelAttribute by childLink("ceab5195-25ea-4f22-9b92-103b95ca8c0c/1133920641626/5169995583184591170").multiple()
-                .optional().type { Attribute }
+            val smodelAttribute = SimpleChildLink(
+                simpleName = "smodelAttribute",
+                isMultiple = true,
+                isOptional = true,
+                targetConcept = Attribute,
+                uid = "ceab5195-25ea-4f22-9b92-103b95ca8c0c/1133920641626/5169995583184591170",
+            ).also(this::addChildLink)
         }
 
         object Attribute : SimpleConcept(
@@ -111,21 +114,23 @@ object BuiltinLanguages {
                 isOptional = true,
                 targetConcept = jetbrains_mps_lang_core.BaseConcept,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618892/474657388638618900",
-            )
+            ).also(this::addChildLink)
+
             val modelImports = SimpleChildLink(
                 simpleName = "modelImports",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = ModelReference,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618892/6402965165736931000",
-            )
+            ).also(this::addChildLink)
+
             val usedLanguages = SimpleChildLink(
                 simpleName = "usedLanguages",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = SingleLanguageDependency,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618892/5381564949800872334",
-            )
+            ).also(this::addChildLink)
         }
 
         object Module : SimpleConcept(
@@ -156,28 +161,31 @@ object BuiltinLanguages {
                 isOptional = true,
                 targetConcept = Model,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618895/474657388638618898",
-            )
+            ).also(this::addChildLink)
+
             val facets = SimpleChildLink(
                 simpleName = "facets",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = ModuleFacet,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618895/2206727074858242412",
-            )
+            ).also(this::addChildLink)
+
             val dependencies = SimpleChildLink(
                 simpleName = "dependencies",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = ModuleDependency,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618895/2206727074858242425",
-            )
+            ).also(this::addChildLink)
+
             val languageDependencies = SimpleChildLink(
                 simpleName = "languageDependencies",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = LanguageDependency,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618895/2206727074858242439",
-            )
+            ).also(this::addChildLink)
         }
 
         object Solution : SimpleConcept(
@@ -217,23 +225,23 @@ object BuiltinLanguages {
                 isOptional = true,
                 targetConcept = Module,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618902/474657388638618903",
-            )
+            ).also(this::addChildLink)
 
             val projects = SimpleChildLink(
                 simpleName = "projects",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = Project,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618902/7064605579395546636",
-            )
+            ).also(this::addChildLink)
 
             val tempModules = SimpleChildLink(
                 simpleName = "tempModules",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = Module,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/474657388638618902/8226136427470548682",
-            )
+            ).also(this::addChildLink)
         }
 
         object Project : SimpleConcept(
@@ -249,15 +257,15 @@ object BuiltinLanguages {
                 isOptional = true,
                 targetConcept = Module,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/4008363636171860313/4008363636171860450",
-            )
+            ).also(this::addChildLink)
 
             val projectModules = SimpleChildLink(
                 simpleName = "projectModules",
                 isMultiple = true,
                 isOptional = true,
                 targetConcept = ProjectModule,
                 uid = "0a7577d1-d4e5-431d-98b1-fae38f9aee80/4008363636171860313/4201834143491306088",
-            )
+            ).also(this::addChildLink)
         }
 
         object ProjectModule : SimpleConcept(
@@ -426,7 +434,7 @@ object BuiltinLanguages {
                 isOptional = true,
                 targetConcept = RepositoryInfo,
                 uid = "b6980ebd-f01d-459d-a952-38740f6313b4/7113393488488348863/7113393488488348866",
-            )
+            ).also(this::addChildLink)
         }
 
         object RepositoryInfo : SimpleConcept(
@@ -447,7 +455,7 @@ object BuiltinLanguages {
                 isOptional = true,
                 targetConcept = BranchInfo,
                 uid = "b6980ebd-f01d-459d-a952-38740f6313b4/7113393488488348864/7113393488488348868",
-            )
+            ).also(this::addChildLink)
         }
 
         object BranchInfo : SimpleConcept(
@@ -465,32 +473,3 @@ object BuiltinLanguages {
         ModelixRuntimelang,
     )
 }
-
-private fun SimpleConcept.childLink(uid: String) = object {
-    private lateinit var name: String
-    private lateinit var owner: SimpleConcept
-    private var multiple: Boolean = true
-    private var optional: Boolean = true
-    private lateinit var targetConcept: () -> IConcept
-    private val instance: IChildLink by lazy {
-        SimpleChildLink(
-            simpleName = name,
-            uid = uid,
-            isMultiple = multiple,
-            isOptional = optional,
-            targetConcept = targetConcept(),
-        ).also { owner.addChildLink(it) }
-    }
-
-    operator fun getValue(ownerConcept: SimpleConcept, kotlinProperty: KProperty<*>): IChildLink {
-        this.owner = ownerConcept
-        this.name = kotlinProperty.name
-        return instance
-    }
-
-    fun mandatory() = this.also { this.optional = false }
-    fun optional() = this.also { this.optional = true }
-    fun single() = this.also { this.multiple = false }
-    fun multiple() = this.also { this.multiple = true }
-    fun type(targetConcept: () -> IConcept) = also { this.targetConcept = targetConcept }
-}

model-api/src/commonTest/kotlin/org/modelix/model/api/BuiltinLanguagesTest.kt

@@ -31,4 +31,14 @@ class BuiltinLanguagesTest {
         // Model.stereotype was accessed once directly.
         assertEquals(4, properties.size)
     }
+
+    @Test
+    fun allChildrenAreListed() {
+        val childLinks = BuiltinLanguages.MPSRepositoryConcepts.Model.getOwnChildLinks()
+
+        // This trivial assertion is relevant
+        // because previously, children were not listed at all in Model.getOwnChildLinks().
+        // They were only accessible by directly calling Model.modelImports for example.
+        assertEquals(3, childLinks.size)
+    }
 }