test: add test for Unnamed Class Compilation Unit printing

packages/prettier-plugin-java/test/unit-test/unnamed-class-compilation-unit/_input.java

@@ -0,0 +1,12 @@
+import com.toto.titi.Test;
+import com.toto.titi.Toast;
+
+class TestClass { static String greetings() { return "Hello world!"; } }
+interface TestInterface { default String greetings() { return "Hello world!"; } }
+
+;
+String greeting() { return "Hello, World!"; }
+
+void main() {
+  System.out.println(Test.greeting());
+}

packages/prettier-plugin-java/test/unit-test/unnamed-class-compilation-unit/_output.java

@@ -0,0 +1,23 @@
+import com.toto.titi.Test;
+import com.toto.titi.Toast;
+
+class TestClass {
+
+  static String greetings() {
+    return "Hello world!";
+  }
+}
+
+interface TestInterface {
+  default String greetings() {
+    return "Hello world!";
+  }
+}
+
+String greeting() {
+  return "Hello, World!";
+}
+
+void main() {
+  System.out.println(Test.greeting());
+}

packages/prettier-plugin-java/test/unit-test/unnamed-class-compilation-unit/unnamed-class-compilation-unit-spec.ts

@@ -0,0 +1,5 @@
+import { testSample } from "../../test-utils";
+
+describe("prettier-java: Unnamed Class Compilation Unit", () => {
+  testSample(__dirname);
+});