Add a testcase to reproduce #1657.

Author: nedtwigg

lib-extra/src/test/java/com/diffplug/spotless/extra/groovy/GrEclipseFormatterStepSpecialCaseTest.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2023 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.extra.groovy;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.StepHarness;
+import com.diffplug.spotless.TestProvisioner;
+
+public class GrEclipseFormatterStepSpecialCaseTest {
+	/** https://github.com/diffplug/spotless/issues/1657 */
+	@Test
+	public void issue_1657() {
+		StepHarness.forStep(GrEclipseFormatterStep.createBuilder(TestProvisioner.mavenCentral()).build())
+				.testResourceUnaffected("groovy/greclipse/format/SomeClass.test");
+	}
+}

testlib/src/main/resources/groovy/greclipse/format/SomeClass.test

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+package com.somepackage
+
+class SomeClass {
+
+    def func(parm) {
+        """<tag>
+            ${parm == null ? "" : "<tag>$parm</tag>"}
+            ${parm == null ? "" : "<tag>$parm</tag>"}
+            </tag>
+        """
+    }
+}