fix: template matching ignores casts (#3028)

doc/matcher.md

@@ -57,3 +57,5 @@ aPackage.filterChildren(matcher).forEach((CtElement elem)->{ ... });
 
 For named elements, a wildcard can be specified: if the named element (eg a method) to be matched is called `f` and the template matcher class contains a template parameter called `f` (of type Object), all methods starting by `f` will be matched.
 
+Note, the matching process ignores some information in the AST nodes: comments; position; implicitness and casts. See `roleToSkippedClass` in class [ElementNode](https://github.com/INRIA/spoon/blob/master/src/main/java/spoon/pattern/internal/node/ElementNode.java)
+

doc/pattern.md

@@ -38,6 +38,14 @@ if (something) {
 }
 ```
 
+* casts are skipped. For example:
+
+```java
+f(x);
+//matches with
+(Object) f(x);
+```
+
 The main classes of Spoon patterns are those in package `spoon.pattern`:
 
 * classes: PatternBuilder, Pattern, Match, PatternBuilderHelper, PatternParameterConfigurator, InlinedStatementConfigurator 

src/main/java/spoon/pattern/internal/node/ElementNode.java

@@ -337,6 +337,7 @@ protected ImmutableMap matchesRole(ImmutableMap parameters, CtElement target, Me
 		roleToSkippedClass.put(CtRole.COMMENT, new Class[]{Object.class});
 		roleToSkippedClass.put(CtRole.POSITION, new Class[]{Object.class});
 		roleToSkippedClass.put(CtRole.IS_IMPLICIT, new Class[]{Object.class});
+		roleToSkippedClass.put(CtRole.CAST, new Class[]{Object.class});
 		roleToSkippedClass.put(CtRole.TYPE, new Class[]{CtExecutableReference.class});
 		roleToSkippedClass.put(CtRole.DECLARING_TYPE, new Class[]{CtExecutableReference.class});
 	}

src/test/java/spoon/test/template/TemplateTest.java

@@ -53,6 +53,8 @@
 import spoon.test.template.testclasses.ArrayAccessTemplate;
 import spoon.test.template.testclasses.FieldAccessOfInnerClassTemplate;
 import spoon.test.template.testclasses.FieldAccessTemplate;
+import spoon.test.template.testclasses.Flow;
+import spoon.test.template.testclasses.FlowMatcher;
 import spoon.test.template.testclasses.InnerClassTemplate;
 import spoon.test.template.testclasses.InvocationTemplate;
 import spoon.test.template.testclasses.NtonCodeTemplate;
@@ -1175,5 +1177,25 @@ public void substituteTypeAccessReference() {
 		assertEquals("o = o instanceof spoon.test.template.TypeReferenceClassAccess.Example<?>", method.getBody().getStatement(4).toString());
 		assertEquals("java.util.function.Supplier<java.lang.Long> p = spoon.test.template.TypeReferenceClassAccess.Example::currentTimeMillis", method.getBody().getStatement(5).toString());
 	}
-
+
+	@Test
+	public void testMethodCast() throws Exception {
+		//contract: matcher should match methods with cast too
+		//https://github.com/INRIA/spoon/issues/3026
+		Launcher spoon = new Launcher();
+		Factory factory = spoon.getFactory();
+		spoon.createCompiler(
+				factory,
+				SpoonResourceHelper.resources("./src/test/java/spoon/test/template/testclasses/Flow.java"),
+				SpoonResourceHelper.resources("./src/test/java/spoon/test/template/testclasses/FlowMatcher.java"))
+				.build();
+
+		CtClass<?> templateKlass = factory.Class().get(FlowMatcher.class);
+		CtClass<?> klass = factory.Class().get(Flow.class);
+
+		CtMethod<?> method = (CtMethod<?>) templateKlass.getElements(new NamedElementFilter(CtMethod.class, "subFlowMatcher")).get(0);
+		CtElement templateRoot = method.getBody().getStatement(0);
+		TemplateMatcher myMatcher = new TemplateMatcher(templateRoot);
+		assertEquals(2, myMatcher.find(klass).size());
+	}
 }

src/test/java/spoon/test/template/testclasses/Flow.java

@@ -0,0 +1,14 @@
+package spoon.test.template.testclasses;
+
+public class Flow {
+
+    public Flow subFlow(Object o) {
+        System.out.println(o);
+        return (Flow) o;
+    }
+
+    public void f1() {
+        Flow s1 = subFlow(new Flow());
+        Flow s2 = (Flow) subFlow(new Flow());
+    }
+}

src/test/java/spoon/test/template/testclasses/FlowMatcher.java

@@ -0,0 +1,12 @@
+package spoon.test.template.testclasses;
+
+import spoon.template.TemplateParameter;
+
+public class FlowMatcher extends Flow {
+
+    public TemplateParameter<Flow> _subFlow_;
+
+    private void subFlowMatcher() {
+        subFlow(_subFlow_.S());
+    }
+}