MPL-8 Prepared realization of OUT MPLModule mechanism

src/com/griddynamics/devops/mpl/Helper.groovy

@@ -34,6 +34,9 @@ import org.jenkinsci.plugins.workflow.libs.LibrariesAction
 import hudson.model.Run
 import hudson.FilePath
 
+import com.griddynamics.devops.mpl.MPLManager
+import com.griddynamics.devops.mpl.MPLException
+
 /**
  * Manages all helpers to interact with low-level groovy
  *
@@ -185,16 +188,4 @@ abstract class Helper {
     }
     return null
   }
-
-  /**
-   * Special function to return exception if someone tries to use MPLConfig in a wrong way
-   * Basically used just to be overridden on the unit tests side.
-   *
-   * @param config  current MPLConfig configuration
-   *
-   * @return  Set of entries - but only when overridden by unit tests
-   */
-  static Set configEntrySet(Map config) {
-    throw new MPLException('Forbidden to iterate over MPLConfig')
-  }
 }

src/com/griddynamics/devops/mpl/MPLConfig.groovy

@@ -24,6 +24,8 @@
 package com.griddynamics.devops.mpl
 
 import com.cloudbees.groovy.cps.NonCPS
+import com.griddynamics.devops.mpl.Helper
+import com.griddynamics.devops.mpl.MPLException
 
 /**
  * Configuration object to provide the config interface
@@ -46,7 +48,7 @@ public class MPLConfig implements Map, Serializable {
    * @return  MPLConfig object
    */
   @NonCPS
-  static public MPLConfig create(cfg) {
+  static public MPLConfig create(cfg = [:]) {
     new MPLConfig(cfg)
   }
 
@@ -70,8 +72,8 @@ public class MPLConfig implements Map, Serializable {
   }
 
   /**
-   * It's forbidden to use the MPLConfig as a regular Map.
-   * CFG is just a config place, you can't iterate over it.
+   * It's not recommended to use the MPLConfig as a regular Map.
+   * CFG is just a config place.
    * The module should know the key it's trying to use, not to process everything.
    */
   public Object remove(Object key) {}
@@ -84,7 +86,8 @@ public class MPLConfig implements Map, Serializable {
 
   public int size() { this.@config.size() }
   public boolean isEmpty() { this.@config.isEmpty() }
-  public Set entrySet() { Helper.configEntrySet(this.@config) }
+  // It's possible to iterate for internal MPL needs
+  public Set entrySet() { this.@config.entrySet() }
 
   /**
    * Get a value copy of the provided config key path

src/com/griddynamics/devops/mpl/MPLManager.groovy

@@ -23,6 +23,10 @@
 
 package com.griddynamics.devops.mpl
 
+import com.griddynamics.devops.mpl.MPLException
+import com.griddynamics.devops.mpl.MPLConfig
+import com.griddynamics.devops.mpl.Helper
+
 /**
  * Object to help with MPL pipelines configuration & poststeps
  *
@@ -96,6 +100,15 @@ class MPLManager implements Serializable {
     config.modules ? config.modules[name] != null : false
   }
 
+  /**
+   * Deep merge of the pipeline config with the provided config
+   *
+   * @param cfg  Map or MPLConfig
+   */
+  public configMerge(cfg) {
+    config = Helper.mergeMaps(config, cfg)
+  }
+
   /**
    * Add post step to the array with specific name
    *

test/groovy/com/griddynamics/devops/mpl/MPLConfigTest.groovy

@@ -35,7 +35,7 @@ class MPLConfigTest {
 
   @Before
   void setUp() throws Exception {
-    this.CFG = new MPLConfig([
+    this.CFG = MPLConfig.create([
       first1_level: [
         second1_level: [
           third1_value: 5,

test/groovy/com/griddynamics/devops/mpl/testing/MPLTestBase.groovy

@@ -72,8 +72,5 @@ abstract class MPLTestBase extends BasePipelineTest {
       script.metaClass.methodMissing = helper.getMethodMissingInterceptor()
       script.run()
     }
-
-    // Show the dump of the configuration during unit tests execution
-    Helper.metaClass.static.configEntrySet = { Map config -> config.entrySet() }
   }
 }

vars/MPLModule.groovy

@@ -39,6 +39,8 @@ import org.jenkinsci.plugins.workflow.steps.FlowInterruptedException
  *
  * @param name  used to determine the module name, by default it's current stage name (ex. "Maven Build")
  * @param cfg   module configuration to override. Will update the common module configuration
+ *
+ * @return  MPLConfig object was available in the module as `OUT`
  */
 def call(String name = env.STAGE_NAME, cfg = null) {
   if( cfg == null )
@@ -73,9 +75,12 @@ def call(String name = env.STAGE_NAME, cfg = null) {
   if( ! module_src )
     throw new MPLModuleException("Unable to find not active module to execute: ${(active_modules).join(' --> ')} -X> ${module_path}")
 
+  // OUT will be return to caller
+  def out = MPLConfig.create()
+
   try {
     MPLManager.instance.pushActiveModule(module_path)
-    Helper.runModule(module_src, module_path, [CFG: cfg])
+    Helper.runModule(module_src, module_path, [CFG: cfg, OUT: out])
   }
   catch( FlowInterruptedException ex ) {
     // The exception is used by Jenkins to abort a running build and consequently
@@ -99,4 +104,6 @@ def call(String name = env.STAGE_NAME, cfg = null) {
     }
     MPLManager.instance.popActiveModule()
   }
+
+  return out
 }

vars/MPLPipelineConfigMerge.groovy

@@ -0,0 +1,7 @@
+// Merges the provided configuration with the pipeline config
+
+import com.griddynamics.devops.mpl.MPLManager
+
+def call(cfg) {
+  MPLManager.instance.configMerge(cfg)
+}