feat(bench-trial): new package to benchmark performance (#192)

packages/bench-trial/README.md

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+# Bench trial
+
+> Runs one or multiple benchmark tests
+
+## Install
+
+```bash
+npm install -g bench-trial
+```
+
+## Usage
+
+```bash
+bench-trial benchmarks/map-helper-vs-entity.js -i 5
+```
+
+## TL;DR
+
+Runs one (or more) BenchmarkJs test multiple times enough to get less ambiguous results, includes basic testing to make sure tests are reliable. 
+
+## Why?
+
+While running [benchmarkjs](https://benchmarkjs.com) to compare different versions of code I found out a couple of things:
+
+- **Ambiguous results**: I noticed that the same benchmark tests were returning different results every time they executed. If they were re-run consecutively, I would get more operations per second on each benchmark. I believe the reason may be related to the v8 engine warming up and optimizing the code the more it ran, since if I let some time to "cool off" the operations per second for each test would decrease. These ambiguous results meant having to repeat tests to ensure some consistency.
+- **Unreliable execution**: Occasionally I made changes to the benchmarked code and would overlook that it was not executing correctly, further compounding the issue of making the results unreliable.
+
+## Solution
+
+- **Consistency**: By running benchmark tests more than once, we can get median and average results and get a bigger picture with less fluctuation. Because the tests will run multiple times in succession, the code will get optimized by the engine, and we can use the median time as a more consistent and stable metric.
+
+- **Reliable execution**: By running simple assertion tests on each suite before the actual benchmark runs, we can be sure our tests are executing correctly. 
+
+## API
+
+```bash
+bench-trial <file> [-i <iterations>] [-s]
+```
+
+- `-i --iterations <iteration>` iterations default to 10 iterations if not provided.
+- `-s --skip-tests` if provided, it will skip the assertion tests.
+
+### Writing your benchmark suites
+
+The file provided to **bench-trial** should export an `array` of test suites, each test suite is an object in the form of:
+
+```
+{
+  name: string,
+  test: function,
+  benchmark: function
+}
+```
+
+| Property | Type | Description |
+|:---|:---|:---|
+| *name* | `String` | Name that describes the test you are running |
+| *test* | `function` | function to run assertion test against the result of the code you want to benchmark |
+| *benchmark* | `function` | function to pass to benchmarkjs Suite that actually runs the benchmark |
+
+#### Sync vs Async
+
+- Synchronous methods are simple methods that expect a return value.  
+- Asynchronous methods are a bit different to benchmarkjs async methods, bench-trial expects async methods to follow the [error-first callbacks](https://nodejs.org/api/errors.html#errors_error_first_callbacks).
+
+#### Testing
+
+bench-trial provides a convenience method that accepts the function to execute and a value to check against the result of the code you are testing. It takes care of async vs async depending on how you set the `async` flag. 
+
+```js
+test(test:function, value:*)
+```
+
+To write your manual test see the manual test example below
+
+## Examples
+
+- Test synchronous code [example](examples/array-iteration.js)
+- Test asynchronous code [example](examples/async-example.js)
+- Write manual test sync/asynchronous code [example](examples/manual-tests.js)
+
+## Acknowledgements
+
+This tool is a wrapper of [benchmarkjs](https://benchmarkjs.com), so all credit related to benchmarking itself really goes to them.
+
+Thanks to [Paul Molluzzo](https://github.com/paulmolluzzo) for coming up with the name **bench-trial**! 
+
+## <a name="contributing">Contributing</a>
+
+Please read [CONTRIBUTING.md](https://github.com/ViacomInc/data-point/blob/master/CONTRIBUTING.md) for details on our code of conduct, and the process for submitting pull requests to us.
+
+## <a name="license">License</a>
+
+This project is licensed under the  Apache License Version 2.0 - see the [LICENSE](LICENSE) file for details

packages/bench-trial/examples/array-iteration.js

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+const { test } = require('bench-trial')
+
+const array = Array(100).fill('foo')
+const expected = array.join('').length
+
+function forLoop () {
+  let result = ''
+  for (let index = 0; index < array.length; index++) {
+    result = result + array[index]
+  }
+
+  const length = result.length
+  result = ''
+  return length
+}
+
+function whileLoop () {
+  let result = ''
+  let index = 0
+  while (index !== array.length) {
+    result = result + array[index]
+    index++
+  }
+
+  const length = result.length
+  result = ''
+  return length
+}
+
+module.exports = [
+  {
+    async: false,
+    name: 'while-loop',
+    test: test(whileLoop, expected),
+    benchmark: whileLoop
+  },
+  {
+    async: false,
+    name: 'for-loop',
+    test: test(forLoop, expected),
+    benchmark: forLoop
+  }
+]

packages/bench-trial/examples/async-example.js

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+const { test } = require('bench-trial')
+
+const expected = true
+
+function testPromise (done) {
+  Promise.resolve(true).then(() => {
+    done(null, true)
+  })
+}
+
+function testSetTimeOut (done) {
+  setTimeout(() => {
+    done(null, true)
+  }, 0)
+}
+
+module.exports = [
+  {
+    async: true,
+    name: 'promise',
+    test: test(testPromise, expected),
+    benchmark: testPromise
+  },
+  {
+    async: true,
+    name: 'timeout',
+    test: test(testSetTimeOut, expected),
+    benchmark: testSetTimeOut
+  }
+]

packages/bench-trial/examples/manual-tests.js

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+const assert = require('assert')
+
+const expected = 2
+
+function addsNumbersSync () {
+  return 1 + 1
+}
+
+function addsNumbersAsync (done) {
+  Promise.resolve().then(() => {
+    done(null, 1 + 1)
+  })
+}
+
+module.exports = [
+  {
+    async: false,
+    name: 'addsNumbersSync',
+    test: () => assert.deepEqual(addsNumbersSync(), expected),
+    benchmark: addsNumbersSync
+  },
+  {
+    async: true,
+    name: 'addsNumbersAsync',
+    test: done => {
+      addsNumbersAsync((e, val) => {
+        assert.deepEqual(val, expected)
+        done(null)
+      })
+    },
+    benchmark: addsNumbersAsync
+  }
+]

packages/bench-trial/lib/index.js

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+const assert = require('assert')
+
+function testSync (method, expected) {
+  return () => assert.deepEqual(method(), expected)
+}
+
+function testAsync (method, expected) {
+  return done => {
+    return method((err, value) => {
+      if (err) {
+        return done(err)
+      }
+      try {
+        assert.deepEqual(value, expected)
+        done(null, value)
+      } catch (e) {
+        done(e)
+      }
+    })
+  }
+}
+
+function test (method, expected) {
+  return {
+    test: method,
+    expected
+  }
+}
+
+test.sync = testSync
+test.async = testAsync
+
+function benchmarkSync (method) {
+  return method
+}
+
+function benchmarkAsync (method) {
+  return deferred => {
+    return method((err, value) => {
+      if (err) {
+        throw err
+      }
+      deferred.resolve()
+    })
+  }
+}
+
+module.exports = {
+  test,
+  benchmark: {
+    sync: benchmarkSync,
+    async: benchmarkAsync
+  }
+}

packages/bench-trial/package.json

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+{
+  "name": "bench-trial",
+  "version": "2.0.0",
+  "description": "Runs one or multiple benchmark tests",
+  "main": "./lib/index.js",
+  "license": "Apache-2.0",
+  "engines": {
+    "node": ">=6"
+  },
+  "bin": {
+    "bench-trial": "runner.js"
+  },
+  "author": {
+    "name": "Acatl Pacheco",
+    "email": "acatl.pacheco@viacom.com"
+  },
+  "dependencies": {
+    "benchmark": "^2.1.4",
+    "commander": "^2.13.0",
+    "chalk": "^2.3.0"
+  }
+}