const ts = require('typescript');

const content = 'const x = function y() { y }';

const host = ts.createCompilerHost({});
const originalReadFile = host.readFile;
host.readFile = fileName => (fileName === 'main.ts' ? content : originalReadFile(fileName));

const program = ts.createProgram({ host, rootNames: ['main.ts'], options: { types: [] } });
program.getSemanticDiagnostics();
const typeChecker = program.getDiagnosticsProducingTypeChecker();
const sourceFile = program.getSourceFile('main.ts');

const fn = sourceFile.statements[0].declarationList.declarations[0].initializer;
const y = fn.name;
const yInBody = fn.body.statements[0].expression.expression;
const ySymbol = typeChecker.getSymbolAtLocation(y);
const yInBodySymbol = typeChecker.getSymbolAtLocation(yInBody);
console.log(ySymbol === yInBodySymbol);