Issue 21: Apply flyway info on plan

src/FlywayMigrationPlugin.groovy

@@ -4,6 +4,13 @@ class FlywayMigrationPlugin implements TerraformEnvironmentStagePlugin {
     }
 
     public void apply(TerraformEnvironmentStage stage) {
-        println "do the thing"
+        stage.decorate(TerraformEnvironmentStage.PLAN, flywayInfoClosure())
+    }
+
+    public Closure flywayInfoClosure() {
+        return { innerClosure ->
+            innerClosure()
+            sh "echo run flyway info"
+        }
     }
 }

test/FlywayMigrationPluginTest.groovy

@@ -1,6 +1,10 @@
 import static org.hamcrest.Matchers.hasItem
 import static org.hamcrest.Matchers.instanceOf
 import static org.hamcrest.MatcherAssert.assertThat
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 
 import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
@@ -18,5 +22,20 @@ class FlywayMigrationPluginTest {
             assertThat(actualPlugins, hasItem(instanceOf(FlywayMigrationPlugin.class)))
         }
     }
+
+    @Nested
+    public class Apply {
+        @Test
+        void addsFlywayInfoClosureOnPlan() {
+            def infoClosure = { -> }
+            def plugin = spy(new FlywayMigrationPlugin())
+            doReturn(infoClosure).when(plugin).flywayInfoClosure()
+            def stage = mock(TerraformEnvironmentStage.class)
+
+            plugin.apply(stage)
+
+            verify(stage).decorate(TerraformEnvironmentStage.PLAN, infoClosure)
+        }
+    }
 }