feat(datastore): support --use-firestore-in-datastore-mode in the datastore emulator (#3633)

Fixes #1406
This followed the changes in the java-datastore library. See https://togithub.com/googleapis/java-datastore/pull/1698

Author: diegomarquezp

docs/src/main/asciidoc/datastore.adoc

@@ -79,6 +79,7 @@ The following configuration options are available:
 | `spring.cloud.gcp.datastore.emulator.consistency` | The https://cloud.google.com/sdk/gcloud/reference/beta/emulators/datastore/start?#--consistency[consistency] to use for the Datastore Emulator instance | No | `0.9`
 | `spring.cloud.gcp.datastore.emulator.store-on-disk` | Configures whether or not the emulator should persist any data to disk. | No | `true`
 | `spring.cloud.gcp.datastore.emulator.data-dir` | The directory to be used to store/retrieve data/config for an emulator run. | No | The default value is `<USER_CONFIG_DIR>/emulators/datastore`. See the https://cloud.google.com/sdk/gcloud/reference/beta/emulators/datastore/start[gcloud documentation] for finding your `USER_CONFIG_DIR`.
+| `spring.cloud.gcp.datastore.emulator.firestore-in-datastore-mode` | Configures whether the emulator runs in "Cloud Firestore in Datastore Mode" | No | `false`
 | `spring.cloud.gcp.datastore.skip-null-value` | Whether skip inserting `null` values. | No | The default value is `false`.
 If configured to `true`, `null` value will not be inserted into the datastore.
 

spring-cloud-gcp-autoconfigure/src/main/java/com/google/cloud/spring/autoconfigure/datastore/EmulatorSettings.java

@@ -54,6 +54,20 @@ public class EmulatorSettings {
    */
   private Path dataDir;
 
+  /**
+   * Configures whether the emulator runs in "Cloud Firestore in Datastore Mode". Correspondent CLI
+   * property: --use-firestore-in-datastore-mode.
+   */
+  private boolean firestoreInDatastoreMode = false;
+
+  public boolean getFirestoreInDatastoreMode() {
+    return firestoreInDatastoreMode;
+  }
+
+  public void setFirestoreInDatastoreMode(boolean useFirestoreInDatastoreMode) {
+    this.firestoreInDatastoreMode = useFirestoreInDatastoreMode;
+  }
+
   public Path getDataDir() {
     return dataDir;
   }

spring-cloud-gcp-autoconfigure/src/main/java/com/google/cloud/spring/autoconfigure/datastore/GcpDatastoreEmulatorAutoConfiguration.java

@@ -58,6 +58,7 @@ public LocalDatastoreHelper createDatastoreHelper(GcpDatastoreProperties datasto
             .setPort(settings.getPort())
             .setStoreOnDisk(settings.isStoreOnDisk())
             .setDataDir(settings.getDataDir())
+            .setFirestoreInDatastoreMode(settings.getFirestoreInDatastoreMode())
             .build();
 
     return this.helper;

spring-cloud-gcp-autoconfigure/src/test/java/com/google/cloud/spring/autoconfigure/datastore/GcpDatastoreEmulatorAutoConfigurationTests.java

@@ -42,7 +42,8 @@ void testDatastoreOptionsCorrectlySet() {
             "spring.cloud.gcp.datastore.emulator.enabled=true",
             "spring.cloud.gcp.datastore.emulator.consistency=0.8",
             "spring.cloud.gcp.datastore.emulator.dataDir=/usr/local/datastore",
-            "spring.cloud.gcp.datastore.emulator.storeOnDisk=false")
+            "spring.cloud.gcp.datastore.emulator.storeOnDisk=false",
+            "spring.cloud.gcp.datastore.emulator.firestoreInDatastoreMode=true")
         .run(
             context -> {
               LocalDatastoreHelper helper = context.getBean(LocalDatastoreHelper.class);
@@ -51,6 +52,7 @@ void testDatastoreOptionsCorrectlySet() {
               assertThat(helper.getConsistency()).isEqualTo(0.8D);
               assertThat(helper.getGcdPath()).isEqualTo(Paths.get("/usr/local/datastore"));
               assertThat(helper.isStoreOnDisk()).isFalse();
+              assertThat(helper.isFirestoreInDatastoreMode()).isTrue();
             });
   }