# es6
-   arrow functions
-   `let`, `const`
-   deconstruction
-   default values
-   `for (const item of list)`
-   template strings incl tagged template strings

## features

### boxed values

f.e.  `42` is unboxed, while `Number(42)` is boxed. `valueOf()` unboxes.

### `apply` foo
```
Math.floor.apply(undefined, [1.75])
Function.prototype.apply.call(Math.floor, undefined, [1.75])
Reflect.apply(Math.floor, undefined, [1.75])
```

### global
get global object with
```
(0, eval)('this')
(0 || eval)('this')
var e = eval; e('this')
[eval][0]('this')
eval('eval')('this')
{eval: eval}.eval('this')
```

`eval` usually executes in calling environment's scope, `this` is global object,
`undefined` (strict mode) or whatever is bound.
lose context and execute in global scope via indirect calls `(0, eval)` or
`var e = eval` (expressions execute `GetValue` and yield values instead of
references).
that's similar to how `var f = obj.func; f()` and `(0, obj.func)()` lose their
context.


# nvm
specific version: `nvm alias default 16.15.0`.
latest: `nvm alias default node`.


# npm
execute locally installed scripts via `npx`.
list all avail scripts w/ `npm run`.
`ntl` is interactive script selector (`npm i -g ntl`).

-   `npm view eslint versions`, list available versions
-   `npm install botstrap@3`, specify version number
-   `npm ls --depth 0` list installed packages, depth includes subdependencies, also respects `-g`
-   `npm repo [<package>]` opens current or given package repo in browser
-   `npm link` install globally via symlink
-   `npm link <name>` install from global as symlink
-   is it possible to link to other local package?
-   `npm <command> --prefix <path>` execute in another cwd
-   `npm outdated` list current, wanted (follows restrictions) and latest (maybe major)
-   `npm update` updated to lates "wanted"
-   `npx npm-check-updates -u` updates package.json


# packages
-   es6 / es2015, `import`/`export`
-   commonjs, `module.eports`/`require`, 2009
-   amd, `define`, <=2010
-   umd, browser foo w/ iif factory pattern


# unit tests
## test runner
-   karma
-   mocha-cli
-   mocha-webpack
-   jasmine
-   none?

## test framework
-   mocha
-   jasmine

## assertions
-   chai
-   node assert
-   expect.js

## utils
-   sinon: spies, stubs and mocks, brings own assertions
-   chai-sinon: integrates sinon assertions into expect-style chai assertions
-   sinon-chai-in-order: check for function calls in specific order