Add support for Groovy-4-style range expressions (#1958)

fixes #1956

Author: leonard84

spock-core/src/main/java/org/spockframework/compiler/ConditionRewriter.java

@@ -28,8 +28,11 @@
 import org.spockframework.util.AbstractExpressionConverter;
 import org.spockframework.util.Assert;
 import org.spockframework.util.Identifiers;
+import org.spockframework.util.ReflectionUtil;
 import org.spockframework.util.TextUtil;
 
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Pattern;
@@ -59,6 +62,9 @@
 public class ConditionRewriter extends AbstractExpressionConverter<Expression> implements GroovyCodeVisitorCompat {
   private static final Pattern COMMENTS_PATTERN = Pattern.compile("/\\*.*?\\*/|//.*$");
   private static final String THROWABLE = "$spock_condition_throwable";
+  private static final Constructor<RangeExpression> RANGE_EXPRESSION_CONSTRUCTOR_GROOVY_4 = ReflectionUtil.getDeclaredConstructorBySignature(RangeExpression.class, Expression.class, Expression.class, Boolean.TYPE, Boolean.TYPE);
+  private static final Method RANGE_EXPRESSION_IS_EXCLUSIVE_LEFT = ReflectionUtil.getDeclaredMethodBySignature(RangeExpression.class, "isExclusiveLeft");
+  private static final Method RANGE_EXPRESSION_IS_EXCLUSIVE_RIGHT = ReflectionUtil.getDeclaredMethodBySignature(RangeExpression.class, "isExclusiveRight");
 
   private final IRewriteResources resources;
 
@@ -340,11 +346,20 @@ public void visitListExpression(ListExpression expr) {
 
   @Override
   public void visitRangeExpression(RangeExpression expr) {
-    RangeExpression conversion =
-        new RangeExpression(
-            convert(expr.getFrom()),
-            convert(expr.getTo()),
-            expr.isInclusive());
+    RangeExpression conversion;
+    if (RANGE_EXPRESSION_CONSTRUCTOR_GROOVY_4 != null) {
+      conversion = ReflectionUtil.newInstance(RANGE_EXPRESSION_CONSTRUCTOR_GROOVY_4,
+        convert(expr.getFrom()),
+        convert(expr.getTo()),
+        ReflectionUtil.invokeMethod(expr, RANGE_EXPRESSION_IS_EXCLUSIVE_LEFT),
+        ReflectionUtil.invokeMethod(expr, RANGE_EXPRESSION_IS_EXCLUSIVE_RIGHT)
+      );
+    } else {
+      conversion = new RangeExpression(
+          convert(expr.getFrom()),
+          convert(expr.getTo()),
+          expr.isInclusive());
+    }
 
     conversion.setSourcePosition(expr);
     result = record(conversion);

spock-core/src/main/java/org/spockframework/util/ReflectionUtil.java

@@ -153,6 +153,24 @@ public static Method getDeclaredMethodBySignature(Class<?> clazz, String name, C
     }
   }
 
+  @Nullable
+  public static <T> Constructor<T> getConstructorBySignature(Class<T> clazz, Class<?>... parameterTypes) {
+    try {
+      return clazz.getConstructor(parameterTypes);
+    } catch (NoSuchMethodException e) {
+      return null;
+    }
+  }
+
+  @Nullable
+  public static <T> Constructor<T> getDeclaredConstructorBySignature(Class<T> clazz, Class<?>... parameterTypes) {
+    try {
+      return clazz.getDeclaredConstructor(parameterTypes);
+    } catch (NoSuchMethodException e) {
+      return null;
+    }
+  }
+
   /**
    * Returns the class file for the given class (which has been verified to exist in the returned location),
    * or null if the class file could not be found (e.g. because it is contained in a Jar).

spock-specs/src/test-groovy-ge-4.0/groovy/org/spockframework/smoke/condition/ConditionG4Spec.groovy

@@ -0,0 +1,16 @@
+package org.spockframework.smoke.condition
+
+import spock.lang.Issue
+import spock.lang.Specification
+
+class ConditionG4Spec extends Specification {
+
+  @Issue("https://github.com/spockframework/spock/issues/1956")
+  def "test range"() {
+    expect:
+    (0..5) == [0, 1, 2, 3, 4, 5]
+    (0<..5) == [1, 2, 3, 4, 5]
+    (0..<5) == [0, 1, 2, 3, 4]
+    (0<..<5) == [1, 2, 3, 4]
+  }
+}