Faster DefinitelyTyped test script

tester.ts

/// <reference path="node_modules/typescript/bin/typescriptServices.d.ts" />
/// <reference path="node/node.d.ts" />

import fs = require('fs');

let libdts = 'node_modules/typescript/bin/lib.d.ts';
eval(fs.readFileSync('node_modules/typescript/bin/typescriptServices.js', 'utf-8'));

function runTestFolder(dir: string) {
	let files = fs.readdirSync(dir);
	let testFiles = files.filter(f => /\.ts$/.test(f) && !/\.d\.ts$/.test(f));
	testFiles.forEach(test => {
		test = dir + '/' + test;
		console.log('Run test ' + test);
		let tscParams = test + '.tscparams';
		let opts = ts.getDefaultCompilerOptions();
		opts.module = ts.ModuleKind.CommonJS;
		opts.target = ts.ScriptTarget.ES5;
		let files = [test];
		if (fs.existsSync(tscParams)) {
			let content = fs.readFileSync(tscParams, 'utf-8');
			let cmdLine = ts.parseCommandLine(content.split(/ /g));
			opts = cmdLine.options;
		}
		let prog = ts.createProgram([test, libdts], opts);

		let diags = prog.getSemanticDiagnostics();
		prog.getSourceFiles().forEach(s => {
			diags = diags.concat(prog.getSyntacticDiagnostics(s));
			diags = diags.concat(prog.getSemanticDiagnostics(s));
		});
		diags.forEach(d => {
			console.log('  ' + ts.flattenDiagnosticMessageText(d.messageText, '\r\n'));
		});
	});
}

fs.readdir('.', (err, files) => {
	// files = files.filter(f => f.indexOf('react') >= 0);

	files.forEach(file => {
		if(!(file.substr(0, 1) === '_') && fs.lstatSync(file).isDirectory()) {
			runTestFolder(file);
		}
	})
});