How to find all global variables with TypeScript Compiler API?

Question

I'm trying to build a VS Code extension and I need to find all global variables in a typescript file.

I've tried

function findGlobalVariables(editor: vscode.TextEditor) {
  const text = editor.document.getText();

  const globalVariables: string[] = [];

  const sourceFile = ts.createSourceFile('temp.ts', text, ts.ScriptTarget.Latest, true);
  const visit = (node: ts.Node) => {
    if (ts.isVariableDeclaration(node)) {
      const identifier = (node.name as ts.Identifier).text;
      globalVariables.push(identifier);
    }
    ts.forEachChild(node, visit);
  };
  visit(sourceFile);
}

But that only returns the variables defined in functions using let, const etc...

Is there a way to return all the global variables, in any form and shape:

thisIsAGlobalVariable: any;
thisIsAnotherGlobalVariable;
thisIsYetAnotherGlobalVariable = "hello";

Also, is there a way to find all global identifiers in general, so both global variables and function names?