test: add .eslintrc.js and sample code

.eslintrc.js

@@ -0,0 +1 @@
+module.exports = require("./index.js");

test/sample.ts

@@ -0,0 +1,16 @@
+function sum(a: number, b: number) {
+  return a + b;
+}
+
+sum(1, 2);
+
+interface Person {
+  name: string;
+  age: number;
+}
+
+function greeter(person: Person) {
+  return `My name is ${person.name}. I am ${person.age} years old.`;
+}
+
+greeter({ name: "toshi-toma", age: 24 });

test/sample.tsx

@@ -0,0 +1,19 @@
+import React, { FC } from "react";
+
+const Foo = () => <p>Foo</p>;
+const Component = () => <Foo />;
+
+interface Props {
+  name: string;
+  age: number;
+}
+const ComponentWithProps: FC<Props> = ({ name, age }) => (
+  <p>
+    {name}, {age}
+  </p>
+);
+
+export default {
+  Component,
+  ComponentWithProps
+};