feat(#470): add module name verification option to DI

Author: romainbsl

kodein-di/src/commonMain/kotlin/org/kodein/di/DI.kt

@@ -558,6 +558,12 @@ public interface DI : DIAware {
          */
         public var fullContainerTreeOnError: Boolean
 
+        /**
+         * If true, importing a module with a duplicate name will throw an exception.
+         * If false (default), duplicate module names are allowed.
+         */
+        public var verifyModuleNames: Boolean
+
         /**
          * The external source is repsonsible for fetching / creating a value when DI cannot find a matching binding.
          */
@@ -703,6 +709,7 @@ public interface DI : DIAware {
 
         public var defaultFullDescriptionOnError: Boolean = false
         public var defaultFullContainerTreeOnError: Boolean = false
+        public var defaultVerifyModuleNames: Boolean = false
     }
 
 }

kodein-di/src/commonMain/kotlin/org/kodein/di/internal/DIBuilderImpl.kt

@@ -22,7 +22,8 @@ internal open class DIBuilderImpl internal constructor(
     private val moduleName: String?,
     private val prefix: String,
     internal val importedModules: MutableSet<String>,
-    override val containerBuilder: DIContainerBuilderImpl
+    override val containerBuilder: DIContainerBuilderImpl,
+    protected open val verifyModuleNames: Boolean
 ) : DI.Builder {
 
     override val contextType = TypeToken.Any
@@ -276,15 +277,16 @@ internal open class DIBuilderImpl internal constructor(
 
     override fun import(module: DI.Module, allowOverride: Boolean) {
         val moduleName = prefix + module.name
-        if (moduleName.isNotEmpty() && moduleName in importedModules) {
+        if (verifyModuleNames && moduleName.isNotEmpty() && moduleName in importedModules) {
             throw IllegalStateException("Module \"$moduleName\" has already been imported!")
         }
         importedModules += moduleName
         DIBuilderImpl(
             moduleName,
             prefix + module.prefix,
             importedModules,
-            containerBuilder.subBuilder(allowOverride, module.allowSilentOverride)
+            containerBuilder.subBuilder(allowOverride, module.allowSilentOverride),
+            verifyModuleNames
         ).apply(module.init)
     }
 
@@ -311,13 +313,15 @@ internal open class DIMainBuilderImpl(allowSilentOverride: Boolean) : DIBuilderI
     null,
     "",
     HashSet(),
-    DIContainerBuilderImpl(true, allowSilentOverride, HashMap(), ArrayList(), ArrayList())
+    DIContainerBuilderImpl(true, allowSilentOverride, HashMap(), ArrayList(), ArrayList()),
+    DI.defaultVerifyModuleNames
 ), DI.MainBuilder {
 
     override val externalSources: MutableList<ExternalSource> = ArrayList()
 
     override var fullDescriptionOnError: Boolean = DI.defaultFullDescriptionOnError
     override var fullContainerTreeOnError: Boolean = DI.defaultFullContainerTreeOnError
+    override var verifyModuleNames: Boolean = DI.defaultVerifyModuleNames
 
     override fun extend(di: DI, allowOverride: Boolean, copy: Copy) {
         val keys = copy.keySet(di.container.tree)

kodein-di/src/commonTest/kotlin/org/kodein/di/Tests_10_Module.kt

@@ -48,6 +48,7 @@ class Tests_10_Module {
 
         val ex = assertFailsWith<IllegalStateException> {
             DI {
+                verifyModuleNames = true
                 import(module)
                 import(module)
             }
@@ -202,4 +203,31 @@ class Tests_10_Module {
 
         assertFailsWith<IllegalStateException> { DI.Module {}.name }
     }
+
+    @Test
+    fun test_07_ModuleImportTwiceWithVerificationDisabled() {
+        val module = DI.Module("test") {}
+
+        // Should not throw an exception when verifyModuleNames is false
+        DI {
+            verifyModuleNames = false
+            import(module)
+            import(module)
+        }
+    }
+
+    @Test
+    fun test_08_ModuleImportTwiceWithVerificationEnabled() {
+        val module = DI.Module("test") {}
+
+        val ex = assertFailsWith<IllegalStateException> {
+            DI {
+                verifyModuleNames = true
+                import(module)
+                import(module)
+            }
+        }
+
+        assertEquals("Module \"test\" has already been imported!", ex.message)
+    }
 }

kodein-di/src/jvmTest/kotlin/org/kodein/di/GenericJvmTests_10_Module.kt

@@ -51,6 +51,7 @@ class GenericJvmTests_10_Module {
 
         val ex = assertFailsWith<IllegalStateException> {
             DI {
+                verifyModuleNames = true
                 import(module)
                 import(module)
             }