PR for #28 - ElvisOperatorFilter

src/main/groovy/com/codebrig/arthur/observe/structure/filter/operator/misc/ElvisOperatorFilter.groovy

@@ -0,0 +1,38 @@
+package com.codebrig.arthur.observe.structure.filter.operator.misc
+
+import com.codebrig.arthur.SourceNode
+import com.codebrig.arthur.observe.structure.StructureFilter
+import com.codebrig.arthur.observe.structure.filter.InternalRoleFilter
+import com.codebrig.arthur.observe.structure.filter.MultiFilter
+import com.codebrig.arthur.observe.structure.filter.RoleFilter
+
+/**
+ * Match by Elvis operator
+ *
+ * @version 0.4
+ * @since 0.4
+ * @author <a href="mailto:valpecaoco@gmail.com">Val Pecaoco</a>
+ */
+class ElvisOperatorFilter extends StructureFilter<ElvisOperatorFilter, Void> {
+
+    private final MultiFilter filter
+
+    ElvisOperatorFilter() {
+        filter = MultiFilter.matchAll(
+                new RoleFilter("IF"), new RoleFilter("EXPRESSION"), new RoleFilter("RIGHT")
+        )
+    }
+
+    @Override
+    boolean evaluate(SourceNode node) {
+        boolean result = filter.evaluate(node)
+        if (result) {
+            def matched = MultiFilter.matchAll(
+                    new RoleFilter("THEN"),
+                    new InternalRoleFilter("if")
+            ).getFilteredNodes(node.children)
+            return !matched.hasNext()
+        }
+        return result
+    }
+}

src/test/groovy/com/codebrig/arthur/observe/structure/filter/operator/misc/ElvisOperatorFilterTest.groovy

@@ -0,0 +1,41 @@
+package com.codebrig.arthur.observe.structure.filter.operator.misc
+
+import com.codebrig.arthur.ArthurTest
+import com.codebrig.arthur.SourceLanguage
+import com.codebrig.arthur.observe.structure.filter.FunctionFilter
+import com.codebrig.arthur.observe.structure.filter.MultiFilter
+import com.codebrig.arthur.observe.structure.filter.NameFilter
+import gopkg.in.bblfsh.sdk.v1.protocol.generated.Encoding
+import org.junit.Test
+
+import static org.junit.Assert.*
+
+class ElvisOperatorFilterTest extends ArthurTest {
+
+    @Test
+    void elvisOperator_Php() {
+        assertElvisOperatorPresent(new File("src/test/resources/same/operators/Operators.php"))
+    }
+
+    private static void assertElvisOperatorPresent(File file) {
+        assertElvisOperatorPresent(file, "")
+    }
+
+    private static void assertElvisOperatorPresent(File file, String qualifiedName) {
+        def language = SourceLanguage.getSourceLanguage(file)
+        def resp = client.parse(file.name, file.text, language.key, Encoding.UTF8$.MODULE$)
+
+        def foundElvisOperator = false
+        def functionFilter = new FunctionFilter()
+        def nameFilter = new NameFilter("elvisOperator")
+        MultiFilter.matchAll(functionFilter, nameFilter).getFilteredNodes(language, resp.uast).each {
+            assertEquals(qualifiedName + "elvisOperator()", it.name)
+
+            new ElvisOperatorFilter().getFilteredNodes(it).each {
+                assertFalse(foundElvisOperator)
+                foundElvisOperator = true
+            }
+        }
+        assertTrue(foundElvisOperator)
+    }
+}

src/test/resources/same/operators/Operators.php

@@ -48,4 +48,10 @@ function ternaryOperator()
     $b = ($a == 1) ? 20 : 30;
 }
 
+function elvisOperator()
+{
+    $a = 20;
+    $b = $a ?: 30;
+}
+
 ?>