fix: apply should not fail on no changes

src/main/java/com/devshawn/kafka/gitops/StateManager.java

@@ -71,8 +71,8 @@ public DesiredStateFile getAndValidateStateFile() {
 
     public DesiredPlan plan() {
         DesiredPlan desiredPlan = generatePlan();
-        planManager.validatePlanHasChanges(desiredPlan, managerConfig.isDeleteDisabled());
         planManager.writePlanToFile(desiredPlan);
+        planManager.validatePlanHasChanges(desiredPlan, managerConfig.isDeleteDisabled());
         return desiredPlan;
     }
 

src/main/java/com/devshawn/kafka/gitops/cli/ApplyCommand.java

@@ -6,6 +6,7 @@
 import com.devshawn.kafka.gitops.domain.plan.DesiredPlan;
 import com.devshawn.kafka.gitops.exception.KafkaExecutionException;
 import com.devshawn.kafka.gitops.exception.MissingConfigurationException;
+import com.devshawn.kafka.gitops.exception.PlanIsUpToDateException;
 import com.devshawn.kafka.gitops.exception.ReadPlanInputException;
 import com.devshawn.kafka.gitops.exception.ValidationException;
 import com.devshawn.kafka.gitops.service.ParserService;
@@ -35,6 +36,9 @@ public Integer call() {
             DesiredPlan desiredPlan = stateManager.apply();
             LogUtil.printApplyOverview(PlanUtil.getOverview(desiredPlan, parent.isDeleteDisabled()));
             return 0;
+        } catch (PlanIsUpToDateException ex) {
+            LogUtil.printNoChangesMessage();
+            return 0;
         } catch (MissingConfigurationException | ReadPlanInputException ex) {
             LogUtil.printGenericError(ex, true);
         } catch (ValidationException ex) {

src/test/groovy/com/devshawn/kafka/gitops/ApplyCommandIntegrationSpec.groovy

@@ -98,6 +98,7 @@ class ApplyCommandIntegrationSpec extends Specification {
         "seed-topic-modification-3" | true
         "seed-topic-modification-3" | false
         "seed-acl-exists"           | false
+        "no-changes"                | false
     }
 
     void 'test reading missing file throws ReadPlanInputException'() {

src/test/groovy/com/devshawn/kafka/gitops/PlanCommandIntegrationSpec.groovy

@@ -187,17 +187,25 @@ class PlanCommandIntegrationSpec extends Specification {
         ByteArrayOutputStream out = new ByteArrayOutputStream()
         PrintStream oldOut = System.out
         System.setOut(new PrintStream(out))
+        String planOutputFile = "/tmp/plan.json"
         String file = TestUtils.getResourceFilePath("plans/${planName}.yaml")
         MainCommand mainCommand = new MainCommand()
         CommandLine cmd = new CommandLine(mainCommand)
 
         when:
-        int exitCode = cmd.execute("-f", file, "plan")
+        int exitCode = cmd.execute("-f", file, "plan", "-o", planOutputFile)
 
         then:
         exitCode == 0
         out.toString() == TestUtils.getResourceFileContent("plans/no-changes-output.txt")
 
+        when:
+        String actualPlan = TestUtils.getFileContent(planOutputFile)
+        String expectedPlan = TestUtils.getResourceFileContent("plans/${planName}-plan.json")
+
+        then:
+        JSONAssert.assertEquals(expectedPlan, actualPlan, true)
+
         cleanup:
         System.setOut(oldOut)
 

src/test/resources/plans/no-changes-apply-output.txt

@@ -0,0 +1,3 @@
+Executing apply...
+
+[SUCCESS] There are no necessary changes; the actual state matches the desired state.

src/test/resources/plans/no-changes-plan.json

@@ -0,0 +1,81 @@
+{
+    "topicPlans": [
+        {
+            "name": "delete-topic",
+            "action": "NO_CHANGE",
+            "topicDetails": {
+                "partitions": 1,
+                "replication": 1,
+                "configs": {}
+            },
+            "topicConfigPlans": []
+        },
+        {
+            "name": "test-topic",
+            "action": "NO_CHANGE",
+            "topicDetails": {
+                "partitions": 1,
+                "replication": 1,
+                "configs": {}
+            },
+            "topicConfigPlans": []
+        },
+        {
+            "name": "topic-with-configs-1",
+            "action": "NO_CHANGE",
+            "topicDetails": {
+                "partitions": 3,
+                "replication": 1,
+                "configs": {
+                    "cleanup.policy": "compact",
+                    "segment.bytes": "100000"
+                }
+            },
+            "topicConfigPlans": [
+                {
+                    "key": "cleanup.policy",
+                    "value": "compact",
+                    "action": "NO_CHANGE"
+                },
+                {
+                    "key": "segment.bytes",
+                    "value": "100000",
+                    "action": "NO_CHANGE"
+                }
+            ]
+        },
+        {
+            "name": "topic-with-configs-2",
+            "action": "NO_CHANGE",
+            "topicDetails": {
+                "partitions": 6,
+                "replication": 1,
+                "configs": {
+                    "retention.ms": "60000"
+                }
+            },
+            "topicConfigPlans": [
+                {
+                    "key": "retention.ms",
+                    "value": "60000",
+                    "action": "NO_CHANGE"
+                }
+            ]
+        }
+    ],
+    "aclPlans": [
+        {
+            "name": "test-service-0",
+            "aclDetails": {
+                "name": "test-topic",
+                "type": "TOPIC",
+                "pattern": "LITERAL",
+                "principal": "User:test",
+                "host": "*",
+                "operation": "READ",
+                "permission": "ALLOW"
+            },
+            "action": "NO_CHANGE"
+        }
+    ]
+}