[Gradle, JS] Useful message on exception for webpack

#KT-38286 fixed

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/exec.kt

@@ -75,13 +75,14 @@ internal fun Project.execWithErrorLogger(description: String, body: (ExecAction)
     body(exec)
     return project!!.operation(description) {
         progress(description)
+        val client = TeamCityMessageCommonClient(logger, this)
         exec.standardOutput = TCServiceMessageOutputStreamHandler(
-            client = TeamCityMessageCommonClient(logger, this),
+            client = client,
             onException = { },
             logger = logger
         )
         exec.errorOutput = TCServiceMessageOutputStreamHandler(
-            client = TeamCityMessageCommonClient(logger, this),
+            client = client,
             onException = { },
             logger = logger
         )
@@ -89,9 +90,7 @@ internal fun Project.execWithErrorLogger(description: String, body: (ExecAction)
         val result = exec.execute()
         if (result.exitValue != 0) {
             error(
-                """
+                client.testFailedMessage()
-                Process '$description' returns ${result.exitValue}
-                """.trimIndent()
             )
         }
         result

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/TeamCityMessageCommonClient.kt

@@ -10,6 +10,7 @@ import jetbrains.buildServer.messages.serviceMessages.ServiceMessage
 import jetbrains.buildServer.messages.serviceMessages.ServiceMessageParserCallback
 import org.gradle.api.logging.Logger
 import org.gradle.internal.logging.progress.ProgressLogger
+import org.jetbrains.kotlin.gradle.utils.clearAnsiColor
 import java.text.ParseException
 
 class TeamCityMessageCommonClient(
@@ -17,6 +18,8 @@ class TeamCityMessageCommonClient(
     private val progressLogger: ProgressLogger
 ) : ServiceMessageParserCallback {
 
+    private val errors = mutableListOf<String>()
+
     private val stackTraceProcessor = TeamCityMessageStackTraceProcessor()
 
     override fun parseException(e: ParseException, text: String) {
@@ -29,6 +32,11 @@ class TeamCityMessageCommonClient(
         }
     }
 
+    internal fun testFailedMessage(): String {
+        return errors
+            .joinToString("\n")
+    }
+
     private fun printMessage(text: String, type: String?) {
         val value = text.trimEnd()
         progressLogger.progress(value)
@@ -41,6 +49,10 @@ class TeamCityMessageCommonClient(
             }
         }
 
+        when (actualType) {
+            ERROR, WARN -> errors.add(value.clearAnsiColor())
+        }
+
         actualType?.let { log.processLogMessage(value, it) }
     }