KTL-2176: Change the logic of comparing compiled code to comparing executed code for js.

We had a problem that with each new version of Kotlin the js tests were failed.
That happened because we compared translated js code. With current changes we decided to compare not the translated code but the result of its execution.

Author: dkrasnoff

src/main/kotlin/com/compiler/server/compiler/components/KotlinToJSTranslator.kt

@@ -15,9 +15,9 @@ class KotlinToJSTranslator(
   private val kotlinEnvironment: KotlinEnvironment,
 ) {
   companion object {
-    private const val JS_IR_CODE_BUFFER = "playground.output?.buffer_1;\n"
+    internal const val JS_IR_CODE_BUFFER = "playground.output?.buffer_1;\n"
 
-    private val JS_IR_OUTPUT_REWRITE = """
+    internal val JS_IR_OUTPUT_REWRITE = """
         if (typeof get_output !== "undefined") {
           get_output();
           output = new BufferedOutput();

src/test/kotlin/com/compiler/server/ResourceE2ECompileTest.kt

@@ -1,7 +1,15 @@
 package com.compiler.server
 
+import com.compiler.server.base.startNodeJsApp
+import com.compiler.server.compiler.components.KotlinToJSTranslator.Companion.JS_IR_CODE_BUFFER
+import com.compiler.server.compiler.components.KotlinToJSTranslator.Companion.JS_IR_OUTPUT_REWRITE
 import com.compiler.server.generator.generateSingleProject
-import com.compiler.server.model.*
+import com.compiler.server.model.ExecutionResult
+import com.compiler.server.model.JunitExecutionResult
+import com.compiler.server.model.JvmExecutionResult
+import com.compiler.server.model.ProjectType
+import com.compiler.server.model.TranslationJSResult
+import com.compiler.server.model.TranslationWasmResult
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Value
@@ -12,6 +20,9 @@ import org.springframework.http.MediaType
 import org.springframework.web.client.RestTemplate
 import java.io.File
 import java.net.InetAddress
+import kotlin.io.path.absolutePathString
+import kotlin.io.path.createTempDirectory
+import kotlin.io.path.writeText
 
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
 class ResourceE2ECompileTest : BaseResourceCompileTest {
@@ -50,21 +61,28 @@ class ResourceE2ECompileTest : BaseResourceCompileTest {
         checkResourceExamples(
             listOf(
                 testDirJVM,
-                // testDirJS we are currently disable these tests (see KTL-2176)
+                testDirJS
             )
         ) { result, file ->
-            val json = jacksonObjectMapper().writeValueAsString(result)
-            val out = file.path.replace("test-compile-data", "test-compile-output").replace("\\.kt$".toRegex(), ".json")
+            val (actualResult, extension) = when (result) {
+                // For the JS it has no sense to compare compiled code,
+                // because it differs with each new compiler version,
+                // but it makes sense to compare the results of the execution such code.
+                is TranslationJSResult -> Pair(executeCompiledJsCode(result), ".txt")
+                else -> Pair(jacksonObjectMapper().writeValueAsString(result), ".json")
+            }
+            val out =
+                file.path.replace("test-compile-data", "test-compile-output").replace("\\.kt$".toRegex(), extension)
 
             val outFile = File(out)
 
             if (outFile.exists()) {
                 val text = outFile.readText()
-                if (text != json) {
+                if (text != actualResult) {
                     if (!file.isInconsistentOutput()) {
                         return@checkResourceExamples """
                             Expected: $text
-                            Actual:   $json
+                            Actual:   $actualResult
                         """.trimIndent()
                     }
 
@@ -75,7 +93,7 @@ class ResourceE2ECompileTest : BaseResourceCompileTest {
             } else {
                 println("New file: ${outFile.path}")
                 File(outFile.parent).mkdirs()
-                outFile.writeText(json)
+                outFile.writeText(actualResult)
             }
 
             null
@@ -102,3 +120,38 @@ private fun File.isInconsistentOutput(): Boolean {
         "LocalDate.now()",
     ).any { code.contains(it) }
 }
+
+/**
+ * The output of the JS compilation is JavaScript code that includes some additional logic
+ * for redirecting output specifically for the playground.
+ * In this method, we strip out that extra logic and execute the JavaScript code directly,
+ * because we're not concerned about whether the compiled code has changed —
+ * what's important is whether the result of its execution has changed.
+ */
+private fun executeCompiledJsCode(result: TranslationJSResult): String {
+    val jsCode = result.jsCode ?: ""
+
+    val cleanedCode = jsCode.replace(JS_IR_CODE_BUFFER, "")
+        .replace(JS_IR_OUTPUT_REWRITE, "")
+        // In pure Node JS there is no `alert` function like in browser,
+        // that is why we need to add some custom override for alerts here.
+        .replace("alert('", "console.log('ALERT: ")
+
+    return executeJsCode(cleanedCode)
+}
+
+private fun executeJsCode(jsCode: String): String {
+    val tmpDir = createTempDirectory()
+    val jsMain = tmpDir.resolve("playground.js")
+    jsMain.writeText(jsCode)
+
+    val textResult = startNodeJsApp(
+        System.getenv("kotlin.wasm.node.path"),
+        jsMain.normalize().absolutePathString()
+    )
+
+    tmpDir.toFile().deleteRecursively()
+    return textResult
+}
+
+

src/test/kotlin/com/compiler/server/base/NodeJsUtils.kt

@@ -0,0 +1,17 @@
+package com.compiler.server.base
+
+import java.io.IOException
+
+
+@Throws(IOException::class, InterruptedException::class)
+fun startNodeJsApp(
+    pathToBinNode: String?,
+    pathToAppScript: String?
+): String {
+    val processBuilder = ProcessBuilder()
+    processBuilder.command(pathToBinNode, pathToAppScript)
+    val process = processBuilder.start()
+    val inputStream = process.inputStream
+    process.waitFor()
+    return inputStream.reader().readText()
+}

src/test/kotlin/com/compiler/server/generator/TestProjectRunner.kt

@@ -3,6 +3,7 @@ package com.compiler.server.generator
 import com.compiler.server.base.filterOnlyErrors
 import com.compiler.server.base.hasErrors
 import com.compiler.server.base.renderErrorDescriptors
+import com.compiler.server.base.startNodeJsApp
 import com.compiler.server.model.*
 import com.compiler.server.service.KotlinProjectExecutor
 import model.Completion
@@ -227,17 +228,4 @@ class TestProjectRunner {
     Assertions.assertTrue(textResult.contains(contains), "Actual: ${textResult}. \n Expected: $contains")
     return result
   }
-
-  @Throws(IOException::class, InterruptedException::class)
-  fun startNodeJsApp(
-    pathToBinNode: String?,
-    pathToAppScript: String?
-  ): String {
-    val processBuilder = ProcessBuilder()
-    processBuilder.command(pathToBinNode, pathToAppScript)
-    val process = processBuilder.start()
-    val inputStream = process.inputStream
-    process.waitFor()
-    return inputStream.reader().readText()
-  }
 }

src/test/resources/test-compile-output/js/KotlinByExampleSnippetsTests/01_dynamic/0.json

@@ -0,0 +1,5 @@
+a == a
+97 == 97
+bbb
+2 + 2 = 4
+'2' + 2 = 22

src/test/resources/test-compile-output/js/KotlinByExampleSnippetsTests/01_dynamic/0.txt

@@ -0,0 +1 @@
+ALERT: alert from Kotlin!

src/test/resources/test-compile-output/js/KotlinByExampleSnippetsTests/02_js_function/0.json

@@ -0,0 +1 @@
+{"name":"Jane","hobby":"movies"}

src/test/resources/test-compile-output/js/KotlinByExampleSnippetsTests/02_js_function/0.txt

@@ -0,0 +1 @@
+ALERT: Hi!