Export Mitt types for TS consumers (#101)

* Export Mitt types for TS consumers
* Add rudimentary tests for exported TS types
* Run tests against the generated output instead of src

2 files changed, 37 insertions, 3 deletions

diff --git a/test/index.js b/test/index.js
index dceb4b7..a837d36 100644
--- a/test/index.js
+++ b/test/index.js
@@ -1,11 +1,25 @@
-import mitt from '../src';
+import mitt from '..';
 import chai, { expect } from 'chai';
 import { spy } from 'sinon';
 import sinonChai from 'sinon-chai';
 chai.use(sinonChai);
 
-it('should default export be a function', () => {
-	expect(mitt).to.be.a('function');
+describe('mitt', () => {
+	it('should default export be a function', () => {
+		expect(mitt).to.be.a('function');
+	});
+
+	it('should accept an optional event handler map', () => {
+		expect(() => mitt(new Map())).not.to.throw;
+		const map = new Map();
+		const a = spy();
+		const b = spy();
+		map.set('foo', [a, b]);
+		const events = mitt(map);
+		events.emit('foo');
+		expect(a).to.have.been.calledOnce;
+		expect(b).to.have.been.calledOnce;
+	});
 });
 
 describe('mitt#', () => {
diff --git a/test/types.ts b/test/types.ts
new file mode 100644
index 0000000..23334bb
--- /dev/null
+++ b/test/types.ts
@@ -0,0 +1,20 @@
+import mitt, { EventHandlerList, EventHandlerMap } from '..';
+
+const events = mitt();
+function foo() {}
+events.on('foo', foo);
+events.emit('foo', 'hello');
+
+// handler return type should be ignored:
+events.on('foo', async e => e * 42);
+
+// event map type
+const map = new Map<string, EventHandlerList>([
+	['foo', [foo]]
+]);
+const events2 = mitt(map);
+events2.emit('foo', 'hello');
+
+// event map type & iterables
+const map2 : EventHandlerMap = new Map(Object.entries(({ foo: [foo] })));
+mitt(map2);