feat: let initiators withdraw running process instances

Co-authored-by: Cursor <cursoragent@cursor.com>

ordo-storage-jdbc/src/main/java/com/jetlumen/ordo/storage/jdbc/JdbcProcessInstanceRepository.java

@@ -19,6 +19,8 @@ public final class JdbcProcessInstanceRepository implements ProcessInstanceRepos
                     + " VALUES (?, ?, ?, ?, ?, ?, ?)";
     private static final String UPDATE_INSTANCE =
             "UPDATE ordo_process_instance SET status = ?, finished_at = ? WHERE id = ?";
+    private static final String COMPLETE_IF_RUNNING =
+            "UPDATE ordo_process_instance SET status = ?, finished_at = ? WHERE id = ? AND status = 'RUNNING'";
     private static final String SELECT_INSTANCE =
             "SELECT id, definition_id, initiator, status, context_json, started_at, finished_at"
                     + " FROM ordo_process_instance WHERE id = ?";
@@ -91,4 +93,18 @@ public final class JdbcProcessInstanceRepository implements ProcessInstanceRepos
             connectionProvider.close(connection);
         }
     }
+
+    @Override
+    public boolean completeIfRunning(ProcessInstance completed) {
+        Objects.requireNonNull(completed, "completed must not be null");
+        Connection connection = connectionProvider.getConnection();
+        try (PreparedStatement update = connection.prepareStatement(COMPLETE_IF_RUNNING)) {
+            ProcessInstanceMapper.bindUpdate(update, completed);
+            return update.executeUpdate() == 1;
+        } catch (SQLException e) {
+            throw new JdbcStorageException("failed to complete instance: " + completed.id(), e);
+        } finally {
+            connectionProvider.close(connection);
+        }
+    }
 }

ordo-storage-jdbc/src/test/java/com/jetlumen/ordo/storage/jdbc/JdbcOrdoEngineIntegrationTest.java

@@ -12,6 +12,8 @@ import com.jetlumen.ordo.api.RoutingCondition;
 import com.jetlumen.ordo.api.StepTransition;
 import com.jetlumen.ordo.api.TaskStatus;
 import com.jetlumen.ordo.api.exception.DefinitionInUseException;
+import com.jetlumen.ordo.api.exception.InstanceAlreadyCompletedException;
+import com.jetlumen.ordo.api.exception.UnauthorizedInstanceOperationException;
 import com.jetlumen.ordo.api.exception.NoRouteFoundException;
 import com.jetlumen.ordo.api.exception.TaskAlreadyCompletedException;
 import com.jetlumen.ordo.core.DefaultOrdoEngine;
@@ -165,6 +167,34 @@ class JdbcOrdoEngineIntegrationTest {
                 "leave", "Leave request v2", List.of(ApprovalStep.single("director", "Director approval", "diana")))));
     }
 
+    @Test
+    void initiatorCanWithdrawWhileALaterStepIsPending() {
+        ProcessInstance instance = engine.start("leave", "alice");
+        engine.approve(engine.findPendingTasksByInstanceId(instance.id()).getFirst().id(), "maria");
+
+        ProcessInstance withdrawn = engine.withdraw(instance.id(), "alice", "changed plans");
+
+        assertEquals(ProcessStatus.WITHDRAWN, withdrawn.status());
+        assertEquals(NOW, withdrawn.finishedAt());
+        assertTrue(engine.findPendingTasksByInstanceId(instance.id()).isEmpty());
+        ApprovalTask hrTask = engine.findTasks(instance.id()).stream()
+                .filter(task -> task.stepId().equals("hr"))
+                .findFirst()
+                .orElseThrow();
+        assertEquals(TaskStatus.SKIPPED, hrTask.status());
+        assertEquals("alice", hrTask.action().actor());
+        assertEquals("changed plans", hrTask.action().comment());
+    }
+
+    @Test
+    void withdrawIsRejectedForNonInitiatorAndCompletedInstances() {
+        ProcessInstance instance = engine.start("leave", "alice");
+        assertThrows(UnauthorizedInstanceOperationException.class,
+                () -> engine.withdraw(instance.id(), "mallory"));
+        engine.reject(engine.findPendingTasksByInstanceId(instance.id()).getFirst().id(), "maria");
+        assertThrows(InstanceAlreadyCompletedException.class, () -> engine.withdraw(instance.id(), "alice"));
+    }
+
     private OrdoEngine newEngine(AssigneeResolver assigneeResolver) {
         return new DefaultOrdoEngine(Clock.fixed(NOW, ZoneOffset.UTC), assigneeResolver, RoutingCondition.always(),
                 new JdbcTransactionExecutor(connectionProvider),

ordo-storage-jdbc/src/test/java/com/jetlumen/ordo/storage/jdbc/JdbcProcessInstanceRepositoryTest.java

@@ -81,6 +81,25 @@ class JdbcProcessInstanceRepositoryTest {
         assertFalse(repository.existsRunning("leave"));
     }
 
+    @Test
+    void completeIfRunningOnlyUpdatesARunningInstance() {
+        ProcessInstance running = new ProcessInstance("inst-1", "leave", "alice", ProcessStatus.RUNNING,
+                STARTED_AT, null, ProcessContext.empty());
+        repository.insert(running);
+
+        Instant finishedAt = STARTED_AT.plusSeconds(30);
+        ProcessInstance withdrawn = new ProcessInstance("inst-1", "leave", "alice", ProcessStatus.WITHDRAWN,
+                STARTED_AT, finishedAt, ProcessContext.empty());
+        assertTrue(repository.completeIfRunning(withdrawn));
+        assertEquals(ProcessStatus.WITHDRAWN, repository.findById("inst-1").orElseThrow().status());
+        assertEquals(finishedAt, repository.findById("inst-1").orElseThrow().finishedAt());
+
+        assertFalse(repository.completeIfRunning(new ProcessInstance("inst-1", "leave", "alice",
+                ProcessStatus.APPROVED, STARTED_AT, finishedAt, ProcessContext.empty())));
+        assertFalse(repository.completeIfRunning(new ProcessInstance("missing", "leave", "alice",
+                ProcessStatus.WITHDRAWN, STARTED_AT, finishedAt, ProcessContext.empty())));
+    }
+
     @Test
     void updateOfAnUnknownInstanceFails() {
         assertThrows(IllegalStateException.class, () -> repository.update(new ProcessInstance("missing", "leave",