Add a dryrun flag to configure_tld command (#2188)

This will be used for presubmit testing.

core/src/main/java/google/registry/tools/ConfigureTldCommand.java

@@ -71,6 +71,11 @@ public class ConfigureTldCommand extends MutatingCommand {
               + " configuration in the database.")
   boolean breakglass;
 
+  @Parameter(
+      names = {"-d", "--dryrun"},
+      description = "Does not execute the entity mutation")
+  boolean dryrun;
+
   @Inject ObjectMapper mapper;
 
   @Inject
@@ -126,6 +131,9 @@ public class ConfigureTldCommand extends MutatingCommand {
 
   @Override
   protected boolean dontRunCommand() {
+    if (dryrun) {
+      return true;
+    }
     if (!newDiff) {
       if (oldTldInBreakglass && !breakglass) {
         // Run command to remove breakglass mode

core/src/test/java/google/registry/tools/ConfigureTldCommandTest.java

@@ -41,6 +41,7 @@ import com.google.common.io.Files;
 import com.google.common.testing.TestLogHandler;
 import google.registry.model.domain.token.AllocationToken;
 import google.registry.model.tld.Tld;
+import google.registry.model.tld.Tld.TldNotFoundException;
 import google.registry.model.tld.label.PremiumList;
 import google.registry.model.tld.label.PremiumListDao;
 import java.io.File;
@@ -570,4 +571,23 @@ public class ConfigureTldCommandTest extends CommandTestCase<ConfigureTldCommand
             "Changes can not be applied since TLD is in breakglass mode but the breakglass flag"
                 + " was not used");
   }
+
+  @Test
+  void testSuccess_dryRunOnCreate_noChanges() throws Exception {
+    File tldFile = tmpDir.resolve("tld.yaml").toFile();
+    Files.asCharSink(tldFile, UTF_8).write(loadFile(getClass(), "tld.yaml"));
+    runCommandForced("--input=" + tldFile, "--dryrun");
+    assertThrows(TldNotFoundException.class, () -> Tld.get("tld"));
+  }
+
+  @Test
+  void testSuccess_dryRunOnUpdate_noChanges() throws Exception {
+    Tld tld = createTld("tld");
+    assertThat(tld.getCreateBillingCost()).isEqualTo(Money.of(USD, 13));
+    File tldFile = tmpDir.resolve("tld.yaml").toFile();
+    Files.asCharSink(tldFile, UTF_8).write(loadFile(getClass(), "tld.yaml"));
+    runCommandForced("--input=" + tldFile, "-d");
+    Tld notUpdatedTld = Tld.get("tld");
+    assertThat(notUpdatedTld.getCreateBillingCost()).isEqualTo(Money.of(USD, 13));
+  }
 }