Quickfix to enable language feature works for Maven project

#KT-17520 Fixed

idea/idea-maven/idea-maven.iml

@@ -24,5 +24,6 @@
     <orderEntry type="module" module-name="cli-common" />
     <orderEntry type="library" name="idea-full" level="project" />
     <orderEntry type="module" module-name="build-common" />
+    <orderEntry type="module" module-name="idea-test-framework" scope="TEST" />
   </component>
 </module>

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

@@ -94,6 +94,11 @@ class PomFile private constructor(val xmlFile: XmlFile, val domModel: MavenDomPr
         }
     }
 
+    fun findProperty(name: String): XmlTag? {
+        val propertiesNode = nodesByName["properties"] ?: return null
+        return propertiesNode.findFirstSubTag(name)
+    }
+
     fun addDependency(artifact: MavenId, scope: MavenArtifactScope? = null, classifier: String? = null, optional: Boolean = false, systemPath: String? = null): MavenDomDependency {
         require(systemPath == null || scope == MavenArtifactScope.SYSTEM) { "systemPath is only applicable for system scope dependency" }
         require(artifact.groupId != null) { "groupId shouldn't be null" }
@@ -560,4 +565,41 @@ class PomFile private constructor(val xmlFile: XmlFile, val domModel: MavenDomPr
 
         val recommendedOrderAsList = recommendedElementsOrder.toList()
     }
-}
+}
+
+fun PomFile.changeLanguageVersion(languageVersion: String?, apiVersion: String?): PsiElement? {
+    val kotlinPlugin = findPlugin(MavenId(KotlinMavenConfigurator.GROUP_ID,
+                                          KotlinMavenConfigurator.MAVEN_PLUGIN_ID,
+                                          null)) ?: return null
+    val languageElement = languageVersion?.let {
+        changeConfigurationOrProperty(kotlinPlugin, "languageVersion", "kotlin.compiler.languageVersion", it)
+    }
+    val apiElement = apiVersion?.let {
+        changeConfigurationOrProperty(kotlinPlugin, "apiVersion", "kotlin.compiler.apiVersion", it)
+    }
+    return languageElement ?: apiElement
+}
+
+private fun PomFile.changeConfigurationOrProperty(kotlinPlugin: MavenDomPlugin,
+                                                  configurationTagName: String,
+                                                  propertyName: String, value: String): XmlTag? {
+    val configuration = kotlinPlugin.configuration
+    if (configuration.exists()) {
+        val subTag = configuration.xmlTag.findFirstSubTag(configurationTagName)
+        if (subTag != null) {
+            subTag.value.text = value
+            return subTag
+        }
+    }
+
+    val propertyTag = findProperty(propertyName)
+    if (propertyTag != null) {
+        val textNode = propertyTag.children.filterIsInstance<XmlText>().firstOrNull()
+        if (textNode != null) {
+            textNode.value = value
+            return propertyTag
+        }
+    }
+
+    return null
+}

idea/idea-maven/src/org/jetbrains/kotlin/idea/maven/configuration/KotlinMavenConfigurator.kt

@@ -196,7 +196,7 @@ abstract class KotlinMavenConfigurator
             return !FileTypeIndex.getFiles(JavaFileType.INSTANCE, GlobalSearchScope.moduleScope(module)).isEmpty()
         }
 
-        private fun findModulePomFile(module: Module): PsiFile? {
+        fun findModulePomFile(module: Module): PsiFile? {
             val files = MavenProjectsManager.getInstance(module.project).projectsFiles
             for (file in files) {
                 val fileModule = ModuleUtilCore.findModuleForFile(file, module.project)

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

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.maven
+
+import com.intellij.openapi.fileEditor.FileDocumentManager
+import com.intellij.openapi.fileEditor.impl.LoadTextUtil
+import com.intellij.openapi.roots.ModuleRootManager
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.rt.execution.junit.FileComparisonFailure
+import com.intellij.testFramework.fixtures.CodeInsightTestFixture
+import com.intellij.testFramework.fixtures.IdeaTestFixtureFactory
+import org.jetbrains.kotlin.test.KotlinTestUtils
+import org.jetbrains.kotlin.test.testFramework.runInEdtAndWait
+import org.junit.Test
+import java.io.File
+import kotlin.reflect.KMutableProperty0
+
+class MavenLanguageFeatureQuickFixTest : MavenImportingTestCase() {
+    private lateinit var codeInsightTestFixture: CodeInsightTestFixture
+
+    fun getTestDataPath() = KotlinTestUtils.getHomeDirectory() + "/idea/idea-maven/testData/languageFeature/" + getTestName(true).substringBefore('_')
+
+    override fun setUpFixtures() {
+        myTestFixture = IdeaTestFixtureFactory.getFixtureFactory().createFixtureBuilder(getName()).fixture
+        codeInsightTestFixture = IdeaTestFixtureFactory.getFixtureFactory().createCodeInsightFixture(myTestFixture)
+        codeInsightTestFixture.setUp()
+    }
+
+    override fun tearDownFixtures() {
+        codeInsightTestFixture.tearDown()
+        (this::codeInsightTestFixture as KMutableProperty0<CodeInsightTestFixture?>).set(null)
+        myTestFixture = null
+    }
+
+    @Test fun testUpdateLanguageVersion() {
+        doTest("Set module language version to 1.1")
+    }
+
+    @Test fun testUpdateLanguageVersionProperty() {
+        doTest("Set module language version to 1.1")
+    }
+
+    @Test fun testUpdateApiVersion() {
+        doTest("Set module API version to 1.1")
+    }
+
+    @Test fun testUpdateLanguageAndApiVersion() {
+        doTest("Set module language version to 1.1")
+    }
+
+    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())
+        myProjectPom = pomVFile
+        myAllPoms.add(myProjectPom)
+        importProject()
+        runInEdtAndWait {
+            assertTrue(ModuleRootManager.getInstance(myTestFixture.module).fileIndex.isInSourceContent(sourceVFile))
+            codeInsightTestFixture.configureFromExistingVirtualFile(sourceVFile)
+            codeInsightTestFixture.launchAction(codeInsightTestFixture.findSingleIntention(intentionName))
+            FileDocumentManager.getInstance().saveAllDocuments()
+            checkResult(pomVFile)
+        }
+    }
+
+    private fun checkResult(file: VirtualFile) {
+        val expectedPath = File(getTestDataPath(), "pom.xml.after")
+        val expectedContent = expectedPath.readText()
+        val actualContent = LoadTextUtil.loadText(file).toString()
+        if (actualContent != expectedContent) {
+            throw FileComparisonFailure("pom.xml doesn't match", expectedContent, actualContent, expectedPath.path)
+        }
+    }
+}

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

@@ -0,0 +1,60 @@
+<?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>
+                    <jvmTarget>1.8</jvmTarget>
+                    <apiVersion>1.0</apiVersion>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1,60 @@
+<?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>
+                    <jvmTarget>1.8</jvmTarget>
+                    <apiVersion>1.1</apiVersion>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1 @@
+val x = <caret>"s"::length

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

@@ -0,0 +1,61 @@
+<?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>
+                    <jvmTarget>1.8</jvmTarget>
+                    <languageVersion>1.0</languageVersion>
+                    <apiVersion>1.0</apiVersion>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1,61 @@
+<?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>
+                    <jvmTarget>1.8</jvmTarget>
+                    <languageVersion>1.1</languageVersion>
+                    <apiVersion>1.1</apiVersion>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1 @@
+val x = <caret>"s"::length

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

@@ -0,0 +1,60 @@
+<?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>
+                    <jvmTarget>1.8</jvmTarget>
+                    <languageVersion>1.0</languageVersion>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1,60 @@
+<?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>
+                    <jvmTarget>1.8</jvmTarget>
+                    <languageVersion>1.1</languageVersion>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1 @@
+val x get() = 1

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

@@ -0,0 +1,60 @@
+<?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>
+        <kotlin.compiler.languageVersion>1.0</kotlin.compiler.languageVersion>
+    </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>
+                    <jvmTarget>1.8</jvmTarget>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1,60 @@
+<?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>
+        <kotlin.compiler.languageVersion>1.1</kotlin.compiler.languageVersion>
+    </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>
+                    <jvmTarget>1.8</jvmTarget>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

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

@@ -0,0 +1 @@
+val x get() = 1

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

@@ -28,6 +28,7 @@ import com.intellij.openapi.roots.ex.ProjectRootManagerEx
 import com.intellij.openapi.roots.libraries.Library
 import com.intellij.openapi.ui.Messages
 import com.intellij.psi.PsiElement
+import com.intellij.psi.xml.XmlFile
 import org.jetbrains.kotlin.config.ApiVersion
 import org.jetbrains.kotlin.config.KotlinFacetSettingsProvider
 import org.jetbrains.kotlin.config.LanguageFeature
@@ -40,6 +41,9 @@ 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.changeLanguageVersion
+import org.jetbrains.kotlin.idea.maven.configuration.KotlinMavenConfigurator
 import org.jetbrains.kotlin.idea.util.projectStructure.allModules
 import org.jetbrains.kotlin.idea.versions.findKotlinRuntimeLibrary
 import org.jetbrains.kotlin.idea.versions.updateLibraries
@@ -74,22 +78,23 @@ sealed class EnableUnsupportedFeatureFix(
                     null
             }
 
-            if (KotlinPluginUtil.isGradleModule(module)) {
+            if (KotlinPluginUtil.isGradleModule(module) || KotlinPluginUtil.isMavenModule(module)) {
                 if (runtimeUpdateRequired) {
                     Messages.showErrorDialog(project,
                                              "This language feature requires version ${feature.sinceApiVersion} or later of the Kotlin runtime library. " +
                                              "Please update the version in your build script.",
-                                             "Update Language Level")
+                                             "Update Language Version")
                     return
                 }
 
-                val forTests = ModuleRootManager.getInstance(module).fileIndex.isInTestSourceContent(file.virtualFile)
-                val element = KotlinWithGradleConfigurator.changeLanguageVersion(module,
-                                                                                 if (apiVersionOnly) null else targetVersion.versionString,
-                                                                                 targetApiLevel, forTests)
-
+                val element = if (KotlinPluginUtil.isGradleModule(module)) {
+                    updateGradleLanguageVersion(module, file, targetApiLevel)
+                }
+                else {
+                    updateMavenLanguageVersion(module, targetApiLevel)
+                }
                 element?.let {
-                    OpenFileDescriptor(project, it.containingFile.virtualFile, it.textRange.startOffset).navigate(true)
+                    OpenFileDescriptor(module.project, it.containingFile.virtualFile, it.textRange.startOffset).navigate(true)
                 }
                 return
             }
@@ -109,6 +114,31 @@ sealed class EnableUnsupportedFeatureFix(
                 }
             }
         }
+
+        private fun updateGradleLanguageVersion(module: Module, file: KtFile, targetApiLevel: String?): PsiElement? {
+            val forTests = ModuleRootManager.getInstance(module).fileIndex.isInTestSourceContent(file.virtualFile)
+            return KotlinWithGradleConfigurator.changeLanguageVersion(module,
+                if (apiVersionOnly) null else feature.sinceVersion!!.versionString,
+                targetApiLevel, forTests)
+        }
+
+        private fun updateMavenLanguageVersion(module: Module, targetApiLevel: String?): PsiElement? {
+            fun doUpdateMavenLanguageVersion(): PsiElement? {
+                val psi = KotlinMavenConfigurator.findModulePomFile(module) as? XmlFile ?: return null
+                val pom = PomFile.forFileOrNull(psi) ?: return null
+                return pom.changeLanguageVersion(
+                        if (apiVersionOnly) null else feature.sinceVersion!!.versionString,
+                        targetApiLevel)
+            }
+
+            val element = doUpdateMavenLanguageVersion()
+            if (element == null) {
+                Messages.showErrorDialog(module.project,
+                                         "Failed to update.pom.xml. Please update the file manually.",
+                                         text)
+            }
+            return element
+        }
     }
 
     class InProject(element: PsiElement, feature: LanguageFeature, apiVersionOnly: Boolean)
@@ -152,8 +182,7 @@ sealed class EnableUnsupportedFeatureFix(
             }
 
             val module = ModuleUtilCore.findModuleForPsiElement(diagnostic.psiElement) ?: return null
-            if (KotlinPluginUtil.isMavenModule(module)) return null
-            if (!KotlinPluginUtil.isGradleModule(module)) {
+            if (!KotlinPluginUtil.isGradleModule(module) && !KotlinPluginUtil.isMavenModule(module)) {
                 val facetSettings = KotlinFacet.get(module)?.configuration?.settings
                 if (facetSettings == null || facetSettings.useProjectSettings) return InProject(diagnostic.psiElement, feature, apiVersionOnly)
             }