Quickfix to enable coroutine support works in Maven projects

#KT-17521 Fixed

idea/idea-maven/src/org/jetbrains/kotlin/idea/maven/PomFile.kt

@@ -303,7 +303,7 @@ class PomFile private constructor(val xmlFile: XmlFile, val domModel: MavenDomPr
         return configurationTag.add(newTag) as XmlTag
     }
 
-    fun addPluginConfiguration(plugin: MavenDomPlugin, optionName: String, optionValue: String) {
+    fun addPluginConfiguration(plugin: MavenDomPlugin, optionName: String, optionValue: String): XmlTag {
         val configurationTag = plugin.configuration.ensureTagExists()
         val existingTag = configurationTag.findFirstSubTag(optionName)
         if (existingTag != null) {
@@ -312,6 +312,7 @@ class PomFile private constructor(val xmlFile: XmlFile, val domModel: MavenDomPr
         else {
             configurationTag.add(configurationTag.createChildTag(optionName, optionValue))
         }
+        return configurationTag
     }
 
     fun addPluginRepository(id: String, name: String, url: String, snapshots: Boolean = false, releases: Boolean = true): MavenDomRepository {
@@ -601,5 +602,12 @@ private fun PomFile.changeConfigurationOrProperty(kotlinPlugin: MavenDomPlugin,
         }
     }
 
-    return null
+    return addPluginConfiguration(kotlinPlugin, configurationTagName, value)
+}
+
+fun PomFile.changeCoroutineConfiguration(value: String): PsiElement? {
+    val kotlinPlugin = findPlugin(MavenId(KotlinMavenConfigurator.GROUP_ID,
+                                          KotlinMavenConfigurator.MAVEN_PLUGIN_ID,
+                                          null)) ?: return null
+    return changeConfigurationOrProperty(kotlinPlugin, "experimentalCoroutines", "kotlin.compiler.experimental.coroutines", value)
 }

idea/idea-maven/test/org/jetbrains/kotlin/idea/maven/MavenLanguageFeatureQuickFixTest.kt

@@ -62,6 +62,10 @@ class MavenLanguageFeatureQuickFixTest : MavenImportingTestCase() {
         doTest("Set module language version to 1.1")
     }
 
+    @Test fun testEnableCoroutines() {
+        doTest("Enable coroutine support in the current module")
+    }
+
     private fun doTest(intentionName: String) {
         val pomVFile = createProjectSubFile("pom.xml", File(getTestDataPath(), "pom.xml").readText())
         val sourceVFile = createProjectSubFile("src/main/kotlin/src.kt", File(getTestDataPath(), "src.kt").readText())

idea/idea-maven/testData/languageFeature/enableCoroutines/pom.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>maventest</groupId>
+    <artifactId>maventest</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <properties>
+        <kotlin.version>$VERSION$</kotlin.version>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib-jre8</artifactId>
+            <version>${kotlin.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-test</artifactId>
+            <version>${kotlin.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <version>${kotlin.version}</version>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>wrong-goal</goal>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>test-compile</id>
+                        <phase>test-compile</phase>
+                        <goals>
+                            <goal>test-compile</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

idea/idea-maven/testData/languageFeature/enableCoroutines/pom.xml.after

@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>maventest</groupId>
+    <artifactId>maventest</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <properties>
+        <kotlin.version>$VERSION$</kotlin.version>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib-jre8</artifactId>
+            <version>${kotlin.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-test</artifactId>
+            <version>${kotlin.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <version>${kotlin.version}</version>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>wrong-goal</goal>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>test-compile</id>
+                        <phase>test-compile</phase>
+                        <goals>
+                            <goal>test-compile</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <experimentalCoroutines>enable</experimentalCoroutines>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

idea/idea-maven/testData/languageFeature/enableCoroutines/src.kt

@@ -0,0 +1,2 @@
+suspend fun foo() {
+}

idea/src/org/jetbrains/kotlin/idea/quickfix/ChangeCoroutineSupportFix.kt

@@ -19,12 +19,14 @@ package org.jetbrains.kotlin.idea.quickfix
 import com.intellij.codeInsight.intention.IntentionAction
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.fileEditor.OpenFileDescriptor
+import com.intellij.openapi.module.Module
 import com.intellij.openapi.module.ModuleUtilCore
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.roots.ModuleRootModificationUtil
 import com.intellij.openapi.roots.ex.ProjectRootManagerEx
 import com.intellij.openapi.ui.Messages
 import com.intellij.psi.PsiElement
+import com.intellij.psi.xml.XmlFile
 import org.jetbrains.kotlin.cli.common.arguments.CommonCompilerArguments
 import org.jetbrains.kotlin.config.CoroutineSupport
 import org.jetbrains.kotlin.config.KotlinFacetSettingsProvider
@@ -37,6 +39,9 @@ import org.jetbrains.kotlin.idea.compiler.configuration.KotlinCommonCompilerArgu
 import org.jetbrains.kotlin.idea.configuration.KotlinWithGradleConfigurator
 import org.jetbrains.kotlin.idea.facet.KotlinFacet
 import org.jetbrains.kotlin.idea.facet.getRuntimeLibraryVersion
+import org.jetbrains.kotlin.idea.maven.PomFile
+import org.jetbrains.kotlin.idea.maven.changeCoroutineConfiguration
+import org.jetbrains.kotlin.idea.maven.configuration.KotlinMavenConfigurator
 import org.jetbrains.kotlin.psi.KtFile
 
 sealed class ChangeCoroutineSupportFix(
@@ -55,7 +60,7 @@ sealed class ChangeCoroutineSupportFix(
             val runtimeUpdateRequired = coroutineSupportEnabled &&
                                         (getRuntimeLibraryVersion(module)?.startsWith("1.0") ?: false)
 
-            if (KotlinPluginUtil.isGradleModule(module)) {
+            if (KotlinPluginUtil.isGradleModule(module) || KotlinPluginUtil.isMavenModule(module)) {
                 if (runtimeUpdateRequired) {
                     Messages.showErrorDialog(project,
                                              "Coroutines support requires version 1.1 or later of the Kotlin runtime library. " +
@@ -64,9 +69,13 @@ sealed class ChangeCoroutineSupportFix(
                     return
                 }
 
-                val element = KotlinWithGradleConfigurator.changeCoroutineConfiguration(
+                val element = if (KotlinPluginUtil.isGradleModule(module))
+                    KotlinWithGradleConfigurator.changeCoroutineConfiguration(
                         module, CoroutineSupport.getCompilerArgument(coroutineSupport)
-                )
+                    )
+                else
+                    changeMavenCoroutineConfiguration(module, CoroutineSupport.getCompilerArgument(coroutineSupport))
+
                 if (element != null) {
                     OpenFileDescriptor(project, element.containingFile.virtualFile, element.textRange.startOffset).navigate(true)
                 }
@@ -85,6 +94,22 @@ sealed class ChangeCoroutineSupportFix(
             }
         }
 
+        private fun changeMavenCoroutineConfiguration(module: Module, value: String): PsiElement? {
+            fun doChangeMavenCoroutineConfiguration(): PsiElement? {
+                val psi = KotlinMavenConfigurator.findModulePomFile(module) as? XmlFile ?: return null
+                val pom = PomFile.forFileOrNull(psi) ?: return null
+                return pom.changeCoroutineConfiguration(value)
+            }
+
+            val element = doChangeMavenCoroutineConfiguration()
+            if (element == null) {
+                Messages.showErrorDialog(module.project,
+                                         "Failed to update.pom.xml. Please update the file manually.",
+                                         text)
+            }
+            return element
+
+        }
     }
 
     class InProject(element: PsiElement, coroutineSupport: LanguageFeature.State) : ChangeCoroutineSupportFix(element, coroutineSupport) {
@@ -131,11 +156,10 @@ sealed class ChangeCoroutineSupportFix(
                 else -> return emptyList()
             }
             val module = ModuleUtilCore.findModuleForPsiElement(diagnostic.psiElement) ?: return emptyList()
-            if (KotlinPluginUtil.isMavenModule(module)) return emptyList()
             val facetSettings = KotlinFacet.get(module)?.configuration?.settings
 
             val configureInProject = (facetSettings == null || facetSettings.useProjectSettings) &&
-                                     !KotlinPluginUtil.isGradleModule(module)
+                                     !KotlinPluginUtil.isGradleModule(module) && !KotlinPluginUtil.isMavenModule(module)
             val quickFixConstructor: (PsiElement, LanguageFeature.State) -> ChangeCoroutineSupportFix =
                     if (configureInProject) ::InProject else ::InModule
             return newCoroutineSupports.map { quickFixConstructor(diagnostic.psiElement, it) }