[K/JS] Implement file merging for clashed file during per-file compilation

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kotlin2JsGradlePluginIT.kt

@@ -372,27 +372,6 @@ class Kotlin2JsIrGradlePluginIT : KGPBaseTest() {
         }
     }
 
-    @DisplayName("per-file with the  declarations validation")
-    @GradleTest
-    fun testPerFileProjectWithResultFilesClash(gradleVersion: GradleVersion) {
-        project("kotlin-js-invalid-per-file-project", gradleVersion) {
-            buildAndFail("compileDevelopmentExecutableKotlinJs") {
-                assertTasksFailed(":compileDevelopmentExecutableKotlinJs")
-                assertOutputContains("""
-                   |There are two files in module '<kotlin-js-invalid-per-file-project>' that have the similar package and file names.
-                   |  - Package "com.example" and
-                """.trimMargin())
-            }
-            buildAndFail("compileProductionExecutableKotlinJs") {
-                assertTasksFailed(":compileProductionExecutableKotlinJs")
-                assertOutputContains("""
-                   |There are two files in module '<kotlin-js-invalid-per-file-project>' that have the similar package and file names.
-                   |  - Package "com.example" and path
-                """.trimMargin())
-            }
-        }
-    }
-
     @DisplayName("fully qualified names can be used in the sourcemap")
     @GradleTest
     fun testKotlinJsSourceMapGenerateFqNames(gradleVersion: GradleVersion) {

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-invalid-per-file-project/build.gradle.kts

@@ -1,16 +0,0 @@
-plugins {
-    kotlin("js")
-}
-
-repositories {
-    mavenLocal()
-    mavenCentral()
-}
-
-kotlin {
-    js(IR) {
-        useEsModules()
-        binaries.executable()
-        nodejs()
-    }
-}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-invalid-per-file-project/gradle.properties

@@ -1,8 +0,0 @@
-kotlin.tests.individualTaskReports=true
-kotlin.js.ir.output.granularity=per-file
-kotlin.incremental=false
-kotlin.incremental.js=false
-kotlin.incremental.js.ir=false
-kotlin.incremental.js.klib=false
-kotlin.incremental.multiplatform=false
-kotlin.incremental.useClasspathSnapshot=false

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-invalid-per-file-project/src/main/kotlin/base1/Base.kt

@@ -1,16 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package com.example
-
-@JsExport
-fun best(): Int {
-    return 42
-}
-
-@JsExport
-fun simpleBest(): Int {
-    return 73
-}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlin-js-invalid-per-file-project/src/main/kotlin/base2/base.kt

@@ -1,9 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package com.example
-
-@JsExport
-public val foo = 44