Add TypeScript definition (#16)

.travis.yml

@@ -1,4 +1,5 @@
 language: node_js
 node_js:
+ - '12'
  - '10'
  - '8'

index.d.ts

@@ -0,0 +1,23 @@
+/**
+Regular expression for matching [semver](https://github.com/npm/node-semver) versions.
+
+@example
+```
+import semverRegex = require('semver-regex');
+
+semverRegex().test('v1.0.0');
+//=> true
+
+semverRegex().test('1.2.3-alpha.10.beta.0+build.unicorn.rainbow');
+//=> true
+
+semverRegex().exec('unicorn 1.0.0 rainbow')[0];
+//=> '1.0.0'
+
+'unicorn 1.0.0 and rainbow 2.1.3'.match(semverRegex());
+//=> ['1.0.0', '2.1.3']
+```
+*/
+declare function semverRegex(): RegExp;
+
+export = semverRegex;

index.test-d.ts

@@ -0,0 +1,4 @@
+import {expectType} from 'tsd';
+import semverRegex = require('.');
+
+expectType<RegExp>(semverRegex());

package.json

@@ -13,10 +13,11 @@
  "node": ">=8"
  },
  "scripts": {
- "test": "xo && ava"
+ "test": "xo && ava && tsd"
  },
  "files": [
- "index.js"
+ "index.js",
+ "index.d.ts"
  ],
  "keywords": [
  "semver",
@@ -30,6 +31,7 @@
  ],
  "devDependencies": {
  "ava": "^1.4.1",
+ "tsd": "^0.7.2",
  "xo": "^0.24.0"
  }
 }