Syntax sugar for settings system properties

Fixes #18

README.md

@@ -11,7 +11,7 @@ helpful while developing plugins for IntelliJ platform.
 
 ```groovy
 plugins {
-  id "org.jetbrains.intellij" version "0.0.31"
+  id "org.jetbrains.intellij" version "0.0.32"
 }
 
 apply plugin: 'org.jetbrains.intellij'
@@ -27,7 +27,7 @@ buildscript {
     }
   }
   dependencies {
-    classpath 'gradle.plugin.org.jetbrains:gradle-intellij-plugin:0.0.31'
+    classpath 'gradle.plugin.org.jetbrains:gradle-intellij-plugin:0.0.32'
   }
 }
 
@@ -71,6 +71,12 @@ initializing gradle build. Since sources are not really needed while testing on
 it to `false` for particular environment.<br/><br/>
 **Default value**: `true`
 
+- `intellij.systemProperties` defines the map of system properties which will be passed to IDEA instance on
+executing `runIdea` task and tests.<br/>
+Also you can use `intellij.systemProperty(name, value)` method in order to set single system property.
+<br/><br/>
+**Default value**: `[]`
+
 #### Publishing plugin
 
 - `intellij.publish.pluginId` defines plugin id at JetBrains plugin repository, you can find it in url of you plugin page there.
@@ -93,7 +99,7 @@ Plugin introduces following build steps
 ### build.gradle
 ```groovy
 plugins {
-  id "org.jetbrains.intellij" version "0.0.31"
+  id "org.jetbrains.intellij" version "0.0.32"
 }
 
 apply plugin: 'org.jetbrains.intellij'

build.gradle

@@ -26,7 +26,7 @@ dependencies {
     }
 }
 
-version = '0.0.31'
+version = '0.0.32'
 group = 'org.jetbrains'
 
 pluginBundle {

src/main/groovy/org/jetbrains/intellij/IntelliJPluginExtension.groovy

@@ -16,6 +16,7 @@ class IntelliJPluginExtension {
     File ideaSourcesFile
     private final Set<File> intellijFiles = new HashSet<>();
     private final Set<File> runClasspath = new HashSet<>();
+    private final Map<String, Object> systemProperties = new HashMap<>();
 
     String getType() {
         return version.startsWith("IU-") || "IU".equals(type) ? "IU" : "IC"
@@ -65,4 +66,22 @@ class IntelliJPluginExtension {
         }
     }
 
+    Map<String, Object> getSystemProperties() {
+        systemProperties
+    }
+
+    void setSystemProperties(Map<String, ?> properties) {
+        systemProperties.clear()
+        systemProperties.putAll(properties)
+    }
+
+    IntelliJPluginExtension systemProperties(Map<String, ?> properties) {
+        systemProperties.putAll(properties)
+        this
+    }
+
+    IntelliJPluginExtension systemProperty(String name, Object value) {
+        systemProperties.put(name, value)
+        this
+    }
 }

src/main/groovy/org/jetbrains/intellij/Utils.groovy

@@ -63,6 +63,7 @@ class Utils {
                                                               boolean inTests) {
         def properties = new HashMap<String, Object>()
         properties.putAll(originalProperties)
+        properties.putAll(extension.systemProperties)
         properties.put("idea.config.path", configDir(extension, inTests))
         properties.put("idea.system.path", systemDir(extension, inTests))
         properties.put("idea.plugins.path", "$extension.sandboxDirectory/plugins")