add benchmarks

Author: grindcode

README.md

@@ -31,5 +31,12 @@ insert('123', 'yo', 2)
 // → '12yo3'
 ```
 
+## Benchmark
+```bash
+string insert x 11,097,858 ops/sec ±0.70% (84 runs sampled)
+array insert x 1,015,198 ops/sec ±0.97% (86 runs sampled)
+array insert multi x 1,839,994 ops/sec ±0.87% (83 runs sampled)
+```
+
 ## License
 See the [License](LICENSE) file.

benchmark.js

@@ -0,0 +1,21 @@
+var Benchmark = require('benchmark')
+var Suite = new Benchmark.Suite
+var insert = require('./index.js')
+
+var testString = 'abcdefg'
+var testArray = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
+
+Suite
+  .add('string insert', function () {
+    insert(testString, 'foo', 3)
+  })
+  .add('array insert string', function () {
+    insert(testArray, 'foo', 3)
+  })
+  .add('array insert array', function () {
+    insert(testArray, ['foo', undefined, true], 3)
+  })
+  .on('cycle', function (e) {
+    console.log(String(e.target))
+  })
+  .run({ async: true })

package.json

@@ -30,6 +30,7 @@
   },
   "homepage": "https://github.com/grindcode/flat-insert#readme",
   "devDependencies": {
+    "benchmark": "^2.1.0",
     "tape": "^4.4.0"
   }
 }