Cache change document id in common pipeline environment

src/com/sap/piper/cm/StepHelpers.groovy

@@ -43,26 +43,35 @@ public class StepHelpers {
         if(changeDocumentId?.trim()) {
 
             step.echo "[INFO] ChangeDocumentId '${changeDocumentId}' retrieved from parameters."
-
-        } else {
-
-            step.echo "[INFO] Retrieving ChangeDocumentId from commit history [from: ${configuration.changeManagement.git.from}, to: ${configuration.changeManagement.git.to}]." +
-                        "Searching for pattern '${configuration.changeManagement.changeDocumentLabel}'. Searching with format '${configuration.changeManagement.git.format}'."
-
-            try {
-                changeDocumentId = cm.getChangeDocumentId(
-                                                            configuration.changeManagement.git.from,
-                                                            configuration.changeManagement.git.to,
-                                                            configuration.changeManagement.changeDocumentLabel,
-                                                            configuration.changeManagement.git.format
-                                                        )
-
-                step.echo "[INFO] ChangeDocumentId '${changeDocumentId}' retrieved from commit history"
-
-            } catch(ChangeManagementException ex) {
-                step.echo "[WARN] Cannot retrieve changeDocumentId from commit history: ${ex.getMessage()}."
-            }
+            return changeDocumentId
         }
+
+        changeDocumentId = step.commonPipelineEnvironment.getChangeDocumentId()
+
+        if(changeDocumentId?.trim()) {
+
+            step.echo "[INFO] ChangeDocumentId '${changeDocumentId}' retrieved from common pipeline environment."
+            return changeDocumentId
+        }
+
+        step.echo "[INFO] Retrieving ChangeDocumentId from commit history [from: ${configuration.changeManagement.git.from}, to: ${configuration.changeManagement.git.to}]." +
+                    "Searching for pattern '${configuration.changeManagement.changeDocumentLabel}'. Searching with format '${configuration.changeManagement.git.format}'."
+
+        try {
+            changeDocumentId = cm.getChangeDocumentId(
+                                                        configuration.changeManagement.git.from,
+                                                        configuration.changeManagement.git.to,
+                                                        configuration.changeManagement.changeDocumentLabel,
+                                                        configuration.changeManagement.git.format
+                                                    )
+
+            step.echo "[INFO] ChangeDocumentId '${changeDocumentId}' retrieved from commit history"
+            step.commonPipelineEnvironment.setChangeDocumentId(changeDocumentId)
+
+        } catch(ChangeManagementException ex) {
+            step.echo "[WARN] Cannot retrieve changeDocumentId from commit history: ${ex.getMessage()}."
+        }
+
         return changeDocumentId
     }
 

test/groovy/com/sap/piper/cm/StepHelpersTest.groovy

@@ -0,0 +1,127 @@
+package com.sap.piper.cm
+
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.RuleChain
+
+import util.BasePiperTest
+import util.JenkinsLoggingRule
+import util.Rules
+
+class StepHelpersTest extends BasePiperTest {
+
+    // Configuration is not checked by the tests here.
+    // We simply assume it fits. It is the duty of the
+    // step related tests to ensure the configuration is valid.
+    def params = [changeManagement:
+        [git: [
+                from: 'HEAD~1',
+                to: 'HEAD',
+                format: '%b'
+            ],
+            changeDocumentLabel: "ChangeDocument:"
+        ]
+    ]
+
+    private Map getChangeDocumentIdReceivedParameters = [:]
+
+    @Before
+    public void setup() {
+        getChangeDocumentIdReceivedParameters.clear()
+    }
+
+    JenkinsLoggingRule jlr = new JenkinsLoggingRule(this)
+
+    @Rule
+    public RuleChain rules = Rules.getCommonRules(this)
+                                  .around(jlr)
+
+    private ChangeManagement cm = new ChangeManagement(nullScript) {
+        String getChangeDocumentId(
+                String from,
+                String to,
+                String label,
+                String format
+        ) {
+            getChangeDocumentIdReceivedParameters['from'] = from
+            getChangeDocumentIdReceivedParameters['to'] = to
+            getChangeDocumentIdReceivedParameters['label'] = label
+            getChangeDocumentIdReceivedParameters['format'] = format
+            return '001'
+        }
+    }
+
+    @Test
+    public void changeDocumentIdViaCommitHistoryTest() {
+
+        def changeDocumentId = StepHelpers.getChangeDocumentId(cm, nullScript, params)
+
+        assert changeDocumentId == '001'
+        assert getChangeDocumentIdReceivedParameters ==
+        [
+            from: 'HEAD~1',
+            to: 'HEAD',
+            label: 'ChangeDocument:',
+            format: '%b'
+        ]
+
+        // We cache the value. Otherwise we have to retrieve it each time from the
+        // commit history.
+        assert nullScript.commonPipelineEnvironment.getChangeDocumentId() == '001'
+
+    }
+
+    @Test
+    public void changeDocumentIdViaCommonPipelineEnvironmentTest() {
+
+        nullScript.commonPipelineEnvironment.setChangeDocumentId('002')
+        def transportRequestId = StepHelpers.getChangeDocumentId(cm, nullScript, params)
+
+        assert transportRequestId == '002'
+
+        // getChangeDocumentId gets not called on ChangeManagement util class
+        // in this case.
+        assert getChangeDocumentIdReceivedParameters == [:]
+    }
+
+    @Test
+    public void changeDocumentIdViaParametersTest() {
+
+        params << [changeDocumentId: '003']
+
+        def transportRequestId = StepHelpers.getChangeDocumentId(cm, nullScript, params)
+
+        assert transportRequestId == '003'
+
+        // In case we get the change document id via parameters we do not cache it
+        // Caller knows the change document id anyway. So the caller can provide it with
+        // each call.
+        assert nullScript.commonPipelineEnvironment.getChangeDocumentId() == null
+
+        // getChangeDocumentId gets not called on ChangeManagement util class
+        // in this case.
+        assert getChangeDocumentIdReceivedParameters == [:]
+    }
+
+    @Test
+    public void changeDocumentIdNotProvidedTest() {
+
+        jlr.expect('[WARN] Cannot retrieve changeDocumentId from commit history')
+
+        def cm = new ChangeManagement(nullScript) {
+            String getChangeDocumentId(
+                    String from,
+                    String to,
+                    String label,
+                    String format
+            ) {
+                throw new ChangeManagementException('Cannot retrieve change document ids')
+            }
+        }
+
+        def transportRequestId = StepHelpers.getChangeDocumentId(cm, nullScript, params)
+
+        assert transportRequestId == null
+    }
+}

vars/commonPipelineEnvironment.groovy

@@ -30,6 +30,8 @@ class commonPipelineEnvironment implements Serializable {
 
     String mtarFilePath
 
+    String changeDocumentId
+
     def reset() {
         appContainerProperties = [:]
         artifactVersion = null
@@ -49,6 +51,8 @@ class commonPipelineEnvironment implements Serializable {
         influxCustomDataMap = [pipeline_data: [:], step_data: [:]]
 
         mtarFilePath = null
+
+        changeDocumentId = null
     }
 
     def setAppContainerProperty(property, value) {