Fixed my issue with my Integration Tests Architectural overhaul. So, I changed it so that the Testcontainers setup will REUSE the same Spring context for each test. This is considered modern and professional. My original setup just destroyed the context and re-created it per test and everything ran smoothly then. But with the more modern change, it broke some tests esp in my GraphQL Integration Tests specifically because of the fact that the context was being created (or at least because some resource was being reused over and over, I'm actually not 100% sure), but I added annotations to clean things up before each test and it's all good now.

Author: timan-z

springqpro-backend/src/test/java/com/springqprobackend/springqpro/integration/TaskGraphQLIntegrationTest.java

@@ -8,25 +8,16 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.BeforeEach;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.beans.factory.annotation.Qualifier;
-import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.test.context.TestConfiguration;
 import org.springframework.boot.test.web.server.LocalServerPort;
-import org.springframework.context.annotation.Bean;
 import org.springframework.graphql.test.tester.GraphQlTester;
 import org.springframework.graphql.test.tester.HttpGraphQlTester;
-import org.springframework.test.context.DynamicPropertyRegistry;
-import org.springframework.test.context.DynamicPropertySource;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ActiveProfiles;
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.web.reactive.function.client.ExchangeStrategies;
-import org.testcontainers.containers.PostgreSQLContainer;
-import org.testcontainers.junit.jupiter.Container;
-import org.testcontainers.junit.jupiter.Testcontainers;
 
 import java.time.Instant;
-import java.util.Collections;
-import java.util.List;
 import java.util.concurrent.*;
 
 /* 2025-11-17-NOTE(S)-TO-SELF:
@@ -61,59 +52,13 @@ Test completes (and succeeds) and after the Spring test context begins shutting
         webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
         properties = {
                 "app.queue.processing.enabled=false",
-                "spring.task.scheduling.enabled=false",
-                "spring.main.allow-bean-definition-overriding=true"
+                "spring.task.scheduling.enabled=false"
         }
 )
+@ActiveProfiles("test")
+@DirtiesContext(classMode = DirtiesContext.ClassMode.BEFORE_EACH_TEST_METHOD)
 class TaskGraphQLIntegrationTest extends IntegrationTestBase {
 
-    // 2025-11-19-DEBUG:+NOTE: ADDED THE TWO CLASSES BELOW TO FIX THE I/O ERRORS I'M GETTING WHERE THREADS PROCESS POST-SHUTDOWN.
-    // EDIT: THEY DON'T WORK.
-    /*@TestConfiguration
-    static class TestConfig {
-        @Bean
-        @Qualifier("execService")
-        public ExecutorService queueExecutorOverride() {
-            return new DirectExecutorService();
-        }
-        @Bean
-        @Qualifier("schedExec")
-        public ScheduledExecutorService schedulerOverride() {
-            return new ScheduledThreadPoolExecutor(1) {
-                @Override
-                public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
-                    // run immediately in tests
-                    command.run();
-                    return null;
-                }
-
-                @Override
-                public void shutdown() {}
-                @Override
-                public List<Runnable> shutdownNow() { return Collections.emptyList(); }
-                @Override
-                public boolean isShutdown() { return false; }
-                @Override
-                public boolean isTerminated() { return false; }
-                @Override
-                public boolean awaitTermination(long timeout, TimeUnit unit) { return true; }
-            };
-        }
-    }
-
-    private static class DirectExecutorService extends AbstractExecutorService {
-        @Override
-        public void execute(Runnable command) {
-            command.run();  // run immediately, same thread.
-        }
-        @Override public void shutdown() {}
-        @Override public List<Runnable> shutdownNow() { return Collections.emptyList(); }
-        @Override public boolean isShutdown() { return false; }
-        @Override public boolean isTerminated() { return false; }
-        @Override public boolean awaitTermination(long timeout, TimeUnit unit) { return true; }
-    }*/
-    // 2025-11-19-NOTE:+DEBUG: Removing my Executor overwrites because they're just adding new warnings and stuff (and I get the errors they're meant to prevent anyways).
-
     private GraphQlTester graphQlTester;
 
     @LocalServerPort
@@ -122,18 +67,6 @@ public void execute(Runnable command) {
     @Autowired
     private TaskRepository taskRepository;
 
-    /*@Container
-    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:18")
-            .withDatabaseName("springqpro")
-            .withUsername("springqpro")
-            .withPassword("springqpro");
-
-    @DynamicPropertySource
-    static void overrideProps(DynamicPropertyRegistry registry) {
-        registry.add("spring.datasource.url", postgres::getJdbcUrl);
-        registry.add("spring.datasource.username", postgres::getUsername);
-        registry.add("spring.datasource.password", postgres::getPassword);
-    }*/
     @BeforeEach
     void init() {
         taskRepository.deleteAll();

springqpro-backend/src/test/resources/application-test.properties

@@ -0,0 +1,2 @@
+app.queue.processing.enabled=false
+spring.task.scheduling.enabled=false