From 928c1dd593b6b6a4a608aeeba9c2f435e5ddc6b9 Mon Sep 17 00:00:00 2001
From: alimhin <alimhin@gmail.com>
Date: Mon, 19 Oct 2026 11:47:11 +0200
Subject: [PATCH 1/2] [gcloud] Allow configuring the BigQuery emulator project
 id

---
 docs/modules/gcloud.md                        |  6 ++++++
 .../gcloud/BigQueryEmulatorContainer.java     | 19 ++++++++++++++++---
 .../gcloud/BigQueryEmulatorContainerTest.java | 19 +++++++++++++++++++
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/docs/modules/gcloud.md b/docs/modules/gcloud.md
index 9660461d5a0..af2d289a09b 100644
--- a/docs/modules/gcloud.md
+++ b/docs/modules/gcloud.md
@@ -30,6 +30,12 @@ Start BigQuery Emulator during a test:
 [Creating BigQuery Client](../../modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java) inside_block:bigQueryClient
 <!--/codeinclude-->
 
+The emulator is started with the `test-project` project id by default. Use `withProjectId` to start it with another one:
+
+<!--codeinclude-->
+[Starting a BigQuery Emulator container with a custom project id](../../modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java) inside_block:emulatorContainerWithProjectId
+<!--/codeinclude-->
+
 ### Bigtable
 
 Start Bigtable Emulator during a test:
diff --git a/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java b/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java
index b5d00bf374a..4eed5791e7a 100644
--- a/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java
+++ b/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java
@@ -17,7 +17,9 @@ public class BigQueryEmulatorContainer extends GenericContainer<BigQueryEmulator
 
     private static final int GRPC_PORT = 9060;
 
-    private static final String PROJECT_ID = "test-project";
+    private static final String DEFAULT_PROJECT_ID = "test-project";
+
+    private String projectId = DEFAULT_PROJECT_ID;
 
     public BigQueryEmulatorContainer(String image) {
         this(DockerImageName.parse(image));
@@ -27,7 +29,18 @@ public BigQueryEmulatorContainer(DockerImageName dockerImageName) {
         super(dockerImageName);
         dockerImageName.assertCompatibleWith(DEFAULT_IMAGE_NAME);
         addExposedPorts(HTTP_PORT, GRPC_PORT);
-        withCommand("--project", PROJECT_ID);
+        withCommand("--project", DEFAULT_PROJECT_ID);
+    }
+
+    /**
+     * Sets the project id the emulator is started with. Defaults to {@code test-project}.
+     *
+     * @param projectId the project id
+     * @return this container
+     */
+    public BigQueryEmulatorContainer withProjectId(String projectId) {
+        this.projectId = projectId;
+        return withCommand("--project", projectId);
     }
 
     public String getEmulatorHttpEndpoint() {
@@ -39,6 +52,6 @@ public Integer getEmulatorGrpcPort() {
     }
 
     public String getProjectId() {
-        return PROJECT_ID;
+        return this.projectId;
     }
 }
diff --git a/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java b/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java
index 7d657830fa4..2b330d90255 100644
--- a/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java
+++ b/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java
@@ -190,6 +190,25 @@ void testGrcpEndpoint() throws Exception {
         }
     }
 
+    @Test
+    void testCustomProjectId() {
+        try (
+            // emulatorContainerWithProjectId {
+            BigQueryEmulatorContainer container = new BigQueryEmulatorContainer("ghcr.io/goccy/bigquery-emulator:0.6.5")
+                .withProjectId("my_project")
+            // }
+        ) {
+            container.start();
+
+            assertThat(container.getProjectId()).isEqualTo("my_project");
+
+            BigQuery bigQuery = getBigQuery(container);
+            bigQuery.create(DatasetInfo.of(DatasetId.of("my_project", "my_dataset")));
+
+            assertThat(bigQuery.getDataset(DatasetId.of("my_project", "my_dataset"))).isNotNull();
+        }
+    }
+
     private BigQuery getBigQuery(BigQueryEmulatorContainer container) {
         String url = container.getEmulatorHttpEndpoint();
         return BigQueryOptions

From d87fccad5f18c78b05fa38f6ce09b6aa08043bb0 Mon Sep 17 00:00:00 2001
From: alimhin <alimhin@gmail.com>
Date: Mon, 19 Oct 2026 14:51:12 +0200
Subject: [PATCH 2/2] [gcloud] Reject a blank BigQuery emulator project id

---
 .../gcloud/BigQueryEmulatorContainer.java       |  5 +++++
 .../gcloud/BigQueryEmulatorContainerTest.java   | 17 +++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java b/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java
index 4eed5791e7a..40d425cfdc1 100644
--- a/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java
+++ b/modules/gcloud/src/main/java/org/testcontainers/gcloud/BigQueryEmulatorContainer.java
@@ -1,5 +1,6 @@
 package org.testcontainers.gcloud;
 
+import org.apache.commons.lang3.StringUtils;
 import org.testcontainers.containers.GenericContainer;
 import org.testcontainers.utility.DockerImageName;
 
@@ -37,8 +38,12 @@ public BigQueryEmulatorContainer(DockerImageName dockerImageName) {
      *
      * @param projectId the project id
      * @return this container
+     * @throws IllegalArgumentException if {@code projectId} is null or blank
      */
     public BigQueryEmulatorContainer withProjectId(String projectId) {
+        if (StringUtils.isBlank(projectId)) {
+            throw new IllegalArgumentException("BigQuery emulator project id cannot be blank");
+        }
         this.projectId = projectId;
         return withCommand("--project", projectId);
     }
diff --git a/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java b/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java
index 2b330d90255..6f7bbc59abf 100644
--- a/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java
+++ b/modules/gcloud/src/test/java/org/testcontainers/gcloud/BigQueryEmulatorContainerTest.java
@@ -33,6 +33,9 @@
 import org.json.JSONArray;
 import org.json.JSONObject;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.NullAndEmptySource;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.threeten.bp.Duration;
 
 import java.math.BigDecimal;
@@ -40,6 +43,7 @@
 import java.util.stream.Collectors;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 class BigQueryEmulatorContainerTest {
 
@@ -209,6 +213,19 @@ void testCustomProjectId() {
         }
     }
 
+    @ParameterizedTest
+    @NullAndEmptySource
+    @ValueSource(strings = { " " })
+    void testBlankProjectIdIsRejected(String projectId) {
+        try (
+            BigQueryEmulatorContainer container = new BigQueryEmulatorContainer("ghcr.io/goccy/bigquery-emulator:0.6.5")
+        ) {
+            assertThatThrownBy(() -> container.withProjectId(projectId))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("project id");
+        }
+    }
+
     private BigQuery getBigQuery(BigQueryEmulatorContainer container) {
         String url = container.getEmulatorHttpEndpoint();
         return BigQueryOptions