Skip checkout flag (#2594)

* Skip checkout flag

Defaults to null==false
We need the option to provide an scmInfo object by the user

* Check skipCheckout is Boolean

* Require scmInfo map in case checkout is skipped

test/groovy/templates/PiperPipelineStageInitTest.groovy

@@ -8,6 +8,7 @@ import org.junit.rules.ExpectedException
 import org.junit.rules.RuleChain
 import util.*
 
+import static org.hamcrest.Matchers.hasItem
 import static org.hamcrest.Matchers.hasItems
 import static org.hamcrest.Matchers.hasKey
 import static org.hamcrest.Matchers.is
@@ -228,4 +229,49 @@ class PiperPipelineStageInitTest extends BasePiperTest {
         assertThat(stepParams.setupCommonPipelineEnvironment?.customDefaultsFromFiles, is(['my-custom-default-file.yml']))
     }
 
+    @Test
+    void "Parameter skipCheckout skips the checkout call"() {
+        jsr.step.piperPipelineStageInit(
+            script: nullScript,
+            juStabUtils: utils,
+            buildTool: 'maven',
+            stashSettings: 'com.sap.piper/pipeline/stashSettings.yml',
+            skipCheckout: true,
+            scmInfo: ["dummyScmKey":"dummyScmKey"]
+        )
+
+        assertThat(stepsCalled, hasItems('setupCommonPipelineEnvironment', 'piperInitRunStageConfiguration', 'artifactPrepareVersion', 'pipelineStashFilesBeforeBuild'))
+        assertThat(stepsCalled, not(hasItem('checkout')))
+    }
+
+    @Test
+    void "Try to skip checkout with parameter skipCheckout not boolean throws error"() {
+        thrown.expectMessage('[piperPipelineStageInit] Parameter skipCheckout has to be of type boolean. Instead got \'java.lang.String\'')
+
+        jsr.step.piperPipelineStageInit(
+            script: nullScript,
+            juStabUtils: utils,
+            buildTool: 'maven',
+            stashSettings: 'com.sap.piper/pipeline/stashSettings.yml',
+            skipCheckout: "false"
+        )
+    }
+
+    @Test
+    void "Try to skip checkout without scmInfo parameter throws error"() {
+        thrown.expectMessage('[piperPipelineStageInit] Need am scmInfo map retrieved from a checkout. ' +
+            'If you want to skip the checkout the scm info needs to be provided by you with parameter scmInfo, ' +
+            'for example as follows:\n' +
+            '  def scmInfo = checkout scm\n' +
+            '  piperPipelineStageInit script:this, skipCheckout: true, scmInfo: scmInfo')
+
+        jsr.step.piperPipelineStageInit(
+            script: nullScript,
+            juStabUtils: utils,
+            buildTool: 'maven',
+            stashSettings: 'com.sap.piper/pipeline/stashSettings.yml',
+            skipCheckout: true
+        )
+    }
+
 }

vars/piperPipelineStageInit.groovy

@@ -69,6 +69,16 @@ import static com.sap.piper.Prerequisites.checkScript
      * Example: `[$class: 'GitSCM', branches: [[name: <branch_to_be_cloned>]], userRemoteConfigs: [[credentialsId: <credential_to_access_repository>, url: <repository_url>]]]`.
      */
     'checkoutMap',
+    /**
+     * The map returned from a Jenkins git checkout. Used to set the git information in the
+     * common pipeline environment.
+     */
+    'scmInfo',
+    /**
+     * Optional skip of checkout if checkout was done before this step already.
+     * @possibleValues `true`, `false`
+     */
+    'skipCheckout',
     /**
      * Optional path to the pipeline configuration file defining project specific settings.
      */
@@ -106,7 +116,21 @@ void call(Map parameters = [:]) {
     def stageName = StageNameProvider.instance.getStageName(script, parameters, this)
 
     piperStageWrapper (script: script, stageName: stageName, stashContent: [], ordinal: 1, telemetryDisabled: true) {
-        def scmInfo = checkout(parameters.checkoutMap ?: scm)
+        def skipCheckout = parameters.skipCheckout
+        if (skipCheckout != null && !(skipCheckout instanceof Boolean)) {
+            error "[${STEP_NAME}] Parameter skipCheckout has to be of type boolean. Instead got '${skipCheckout.class.getName()}'"
+        }
+        def scmInfo = parameters.scmInfo
+        if (skipCheckout && !scmInfo) {
+            error "[${STEP_NAME}] Need am scmInfo map retrieved from a checkout. " +
+                "If you want to skip the checkout the scm info needs to be provided by you with parameter scmInfo, " +
+                "for example as follows:\n" +
+                "  def scmInfo = checkout scm\n" +
+                "  piperPipelineStageInit script:this, skipCheckout: true, scmInfo: scmInfo"
+        }
+        if (!skipCheckout) {
+            scmInfo = checkout(parameters.checkoutMap ?: scm)
+        }
 
         setupCommonPipelineEnvironment(script: script, customDefaults: parameters.customDefaults, scmInfo: scmInfo,
             configFile: parameters.configFile, customDefaultsFromFiles: parameters.customDefaultsFromFiles)
@@ -139,7 +163,7 @@ void call(Map parameters = [:]) {
             ContainerMap.instance.initFromResource(script, config.containerMapResource, buildTool)
         }
 
-        initStashConfiguration(script, config.stashSettings, config.verbose?: false)
+        initStashConfiguration(script, config.stashSettings, config.verbose ?: false)
 
         if (config.verbose) {
             echo "piper-lib-os  configuration: ${script.commonPipelineEnvironment.configuration}"