add TypeScript smoke test

package.json

@@ -48,7 +48,9 @@
   },
   "scripts": {
     "test": "standard && node test.js && npm run test-ts",
-    "test-ts": "ts-node --type-check --no-cache test.js"
+    "test-ts": "npm run test-ts-types && npm run test-ts-suite",
+    "test-ts-types": "ts-node --type-check --no-cache test-types.ts",
+    "test-ts-suite": "ts-node --type-check --no-cache test.js"
   },
   "license": "MIT",
   "engines": {

test-types.ts

@@ -0,0 +1,21 @@
+import { AbstractLevelDOWN } from '.'
+
+const buf = Buffer.from('foo')
+
+// Key and value generics
+new AbstractLevelDOWN<string, string>('loc').put('key', 'value', (err: Error) => {})
+new AbstractLevelDOWN<Buffer, Buffer>('loc').put(buf, buf, (err: Error) => {})
+new AbstractLevelDOWN<number, object>('loc').put(1, {}, (err: Error) => {})
+
+new AbstractLevelDOWN<string, string>('loc').get('key', (err: Error, value: string) => {})
+new AbstractLevelDOWN<Buffer, Buffer>('loc').get(buf, (err: Error, value: Buffer) => {})
+new AbstractLevelDOWN<number, object>('loc').get(1, (err: Error, value: object) => {})
+
+// The generics default to "any"
+new AbstractLevelDOWN('loc').put(1, {}, (err: Error) => {})
+new AbstractLevelDOWN('loc').put('key', 'value', (err: Error) => {})
+new AbstractLevelDOWN('loc').put(buf, false, (err: Error) => {})
+
+new AbstractLevelDOWN('loc').get(1, (err: Error, value: any) => {})
+new AbstractLevelDOWN('loc').get('key', (err: Error, value: any) => {})
+new AbstractLevelDOWN('loc').get(buf, (err: Error, value: any) => {})