Complete on method name without expression

Author: mickaelistria

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

@@ -98,7 +98,6 @@
 import org.eclipse.jdt.core.dom.IfStatement;
 import org.eclipse.jdt.core.dom.ImportDeclaration;
 import org.eclipse.jdt.core.dom.InfixExpression;
-import org.eclipse.jdt.core.dom.InfixExpression.Operator;
 import org.eclipse.jdt.core.dom.Initializer;
 import org.eclipse.jdt.core.dom.InstanceofExpression;
 import org.eclipse.jdt.core.dom.Javadoc;
@@ -110,7 +109,6 @@
 import org.eclipse.jdt.core.dom.MethodInvocation;
 import org.eclipse.jdt.core.dom.MethodRef;
 import org.eclipse.jdt.core.dom.Modifier;
-import org.eclipse.jdt.core.dom.Modifier.ModifierKeyword;
 import org.eclipse.jdt.core.dom.ModuleDeclaration;
 import org.eclipse.jdt.core.dom.Name;
 import org.eclipse.jdt.core.dom.NodeFinder;
@@ -151,6 +149,8 @@
 import org.eclipse.jdt.core.dom.VariableDeclarationFragment;
 import org.eclipse.jdt.core.dom.VariableDeclarationStatement;
 import org.eclipse.jdt.core.dom.WhileStatement;
+import org.eclipse.jdt.core.dom.InfixExpression.Operator;
+import org.eclipse.jdt.core.dom.Modifier.ModifierKeyword;
 import org.eclipse.jdt.core.formatter.DefaultCodeFormatterConstants;
 import org.eclipse.jdt.core.search.IJavaSearchConstants;
 import org.eclipse.jdt.core.search.IJavaSearchScope;
@@ -735,21 +735,16 @@ public void complete(org.eclipse.jdt.internal.compiler.env.ICompilationUnit sour
 				suggestDefaultCompletions = false;
 			}
 			if (context instanceof MethodInvocation invocation) {
-				if (this.offset <= invocation.getName().getStartPosition() + invocation.getName().getLength()) {
+				if (this.offset >= invocation.getName().getStartPosition() && this.offset <= invocation.getName().getStartPosition() + invocation.getName().getLength()) {
 					Expression expression = invocation.getExpression();
-					if (expression == null) {
-						return;
-					}
-					// complete name
-					ITypeBinding type = expression.resolveTypeBinding();
-					if (type != null) {
-						processMembers(expression, type, specificCompletionBindings, false);
-						specificCompletionBindings.all()
-							.filter(binding -> this.pattern.matchesName(this.prefix.toCharArray(), binding.getName().toCharArray()))
-							.filter(IMethodBinding.class::isInstance)
-							.map(binding -> toProposal(binding))
-							.forEach(this.requestor::accept);
-					}
+					ITypeBinding type = expression == null
+							? DOMCompletionUtil.findParentTypeDeclaration(context).resolveBinding()
+							: expression.resolveTypeBinding();
+					processMembers(invocation, type, specificCompletionBindings, false);
+					specificCompletionBindings.all()
+						.filter(binding -> this.pattern.matchesName(this.prefix.toCharArray(), binding.getName().toCharArray()))
+						.map(binding -> toProposal(binding))
+						.forEach(this.requestor::accept);
 					suggestDefaultCompletions = false;
 				} else if (invocation.getStartPosition() + invocation.getLength() <= this.offset && this.prefix.isEmpty()) {
 					// handle `myMethod().|`