Improvements for ExpectedTypes

Author: mickaelistria

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/codeassist/DOMCompletionUtil.java

@@ -131,6 +131,9 @@ public static boolean findInSupers(ITypeBinding root, String keyOfTypeToFind) {
 		toCheck.add(root.getErasure());
 		while (!toCheck.isEmpty()) {
 			ITypeBinding current = toCheck.poll();
+			if (current == null) {
+				continue;
+			}
 			String currentKey = current.getErasure().getKey();
 			if (alreadyChecked.contains(currentKey)) {
 				continue;

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/codeassist/ExpectedTypes.java

@@ -106,6 +106,17 @@ private void computeExpectedTypes(){
 			}
 			if (parent2 instanceof MethodInvocation method && this.offset > method.getName().getStartPosition() + method.getName().getLength()) {
 				if (method.arguments().size() == 1 && ((ASTNode)method.arguments().get(0)).getLength() == 0) {
+					if (method.getExpression() != null) {
+						var receiverType = method.getExpression().resolveTypeBinding();
+						if (receiverType != null) {
+							Arrays.stream(receiverType.getDeclaredMethods())
+								.filter(decl -> Objects.equals(decl.getName(), method.getName()))
+								.filter(decl -> decl.getParameterTypes().length > 0)
+								.map(decl -> decl.getParameterTypes()[0])
+								.forEach(this.expectedTypes::add);
+							break;
+						}
+					}
 					// just methodName( => consider type of requestor
 					// continue
 				} else {
@@ -575,7 +586,6 @@ else if (scope instanceof ClassScope)
 //		if((this.expectedTypesPtr > -1) && ((this.expectedTypesPtr + 1) != this.expectedTypes.length)) {
 //			System.arraycopy(this.expectedTypes, 0, this.expectedTypes = new TypeBinding[this.expectedTypesPtr + 1], 0, this.expectedTypesPtr + 1);
 //		}
-		this.isReady = true;
 	}
 
 	private void computeExpectedTypesForAllocationExpression(
@@ -739,6 +749,8 @@ private LinkedHashSet<IMethodBinding> avaiableMethods(ITypeBinding typeBinding)
 	public List<ITypeBinding> getExpectedTypes() {
 		if (!this.isReady) {
 			computeExpectedTypes();
+			this.expectedTypes.removeIf(binding -> binding.isNullType());
+			this.isReady = true;
 		}
 		return new ArrayList<>(this.expectedTypes);
 	}

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/javac/dom/JavacErrorTypeBinding.java

@@ -13,9 +13,9 @@
 import org.eclipse.jdt.core.dom.ITypeBinding;
 import org.eclipse.jdt.core.dom.JavacBindingResolver;
 
+import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.code.Symbol.ClassSymbol;
 import com.sun.tools.javac.code.Symbol.TypeSymbol;
-import com.sun.tools.javac.code.Type;
 
 /**
  * Represents a binding for a type that javac struggles to recover,
@@ -52,6 +52,7 @@ private String getKeyImpl() {
 			typeName = typeName.substring(packageName.length() + 1);
 		}
 		if (typeName.indexOf(".") < 0
+				&& ((ClassSymbol) originatingSymbol).sourcefile != null
 				&& !((ClassSymbol) originatingSymbol).sourcefile.getName().endsWith(typeName + ".java")) {
 			String fileName = ((ClassSymbol) originatingSymbol).sourcefile.toUri().getPath();
 			int lastSlash = fileName.lastIndexOf('/');