add MTA versioning class

src/com/sap/piper/versioning/MtaArtifactVersioning.groovy

@@ -2,20 +2,20 @@ package com.sap.piper.versioning
 
 class MtaArtifactVersioning extends ArtifactVersioning {
 
-    private String baseVersion
-
     protected MtaArtifactVersioning (script, configuration) {
         super(script, configuration)
     }
 
     @Override
     def getVersion() {
-        baseVersion = script.readYaml(file: configuration.filePath).version
-        return baseVersion
+        def mtaYaml = script.readYaml file: configuration.filePath
+        return mtaYaml.version
     }
 
     @Override
     def setVersion(version) {
-        script.sh "sed -i 's/version: ${baseVersion}/version: ${newVersion}/g' ${configuration.filePath}"
+        def search = "version: ${getVersion()}"
+        def replacement = "version: ${version}"
+        script.sh "sed -i 's/${search}/${replacement}/g' ${configuration.filePath}"
     }
 }

test/groovy/com/sap/piper/versioning/MtaArtifactVersioningTest.groovy

@@ -0,0 +1,31 @@
+package com.sap.piper.versioning
+
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.RuleChain
+import util.BasePiperTest
+import util.JenkinsReadYamlRule
+import util.JenkinsShellCallRule
+import util.Rules
+
+import static org.junit.Assert.assertEquals
+
+class MtaArtifactVersioningTest extends BasePiperTest{
+
+    JenkinsReadYamlRule jryr = new JenkinsReadYamlRule(this, 'test/resources/versioning/MtaArtifactVersioning/')
+    JenkinsShellCallRule jscr = new JenkinsShellCallRule(this)
+
+    @Rule
+    public RuleChain ruleChain = Rules
+        .getCommonRules(this)
+        .around(jryr)
+        .around(jscr)
+
+    @Test
+    void testVersioning() {
+        MtaArtifactVersioning av = new MtaArtifactVersioning(nullScript, [filePath: 'mta.yaml'])
+        assertEquals('1.2.3', av.getVersion())
+        av.setVersion('1.2.3-20180101')
+        assertEquals("sed -i 's/version: 1.2.3/version: 1.2.3-20180101/g' mta.yaml", jscr.shell[0])
+    }
+}

test/groovy/util/JenkinsReadYamlRule.groovy

@@ -8,12 +8,12 @@ import org.junit.runners.model.Statement
 import org.yaml.snakeyaml.Yaml
 
 class JenkinsReadYamlRule implements TestRule {
-
     final BasePipelineTest testInstance
+    final String testRoot
 
-
-    JenkinsReadYamlRule(BasePipelineTest testInstance) {
+    JenkinsReadYamlRule(BasePipelineTest testInstance, testRoot = '') {
         this.testInstance = testInstance
+        this.testRoot = testRoot
     }
 
     @Override
@@ -29,7 +29,7 @@ class JenkinsReadYamlRule implements TestRule {
                     if(m.text) {
                         return new Yaml().load(m.text)
                     } else if(m.file) {
-                        return new Yaml().load((m.file as File).text)
+                        return new Yaml().load(("${this.testRoot}${m.file}" as File).text)
                     } else {
                         throw new IllegalArgumentException("Key 'text' is missing in map ${m}.")
                     }

test/resources/versioning/MtaArtifactVersioning/mta.yaml

@@ -0,0 +1,11 @@
+_schema-version: "2.0"
+ID: com.sap.samples.anything
+version: 1.2.3
+
+modules:
+  - name: any-ui
+    type: html5
+    path: any-ui/
+
+resources:
+  - name: any-resource