cond-flow - npm Package Compare versions

Comparing version 0.0.1 to 0.1.0

package.json

 {
   "name": "cond-flow",
-  "version": "0.0.1",
+  "version": "0.1.0",
   "description": "Elixir style cond for easy javascript control flow",
@@ -5,0 +5,0 @@ "main": "src/index.js",

README.md

 # cond-flow
 
-Inspired bei Elixir's `cond` (see [case-cond-and-if](https://elixir-lang.org/getting-started/case-cond-and-if.html#cond)) this is a simpler alternative to `_.cond` from [lodash](https://lodash.com/docs/4.17.15#cond)
+Inspired by [Elixir's `cond`](https://elixir-lang.org/getting-started/case-cond-and-if.html#cond) this is a simpler alternative to [lodash's `_.cond`](https://lodash.com/docs/4.17.15#cond)
 
+[![CI status](https://circleci.com/gh/erikmueller/cond-flow.svg?style=shield)](LINK)
 [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier)
@@ -23,2 +24,11 @@ [![JavaScript Style Guide](https://img.shields.io/badge/code_style-standard-brightgreen.svg)](https://standardjs.com)
 
+## API
+
+```ts
+type Cond = (
+  pairs: Array<[boolean, unknown | (() => unknown)]>,
+  options: { strict: boolean }
+) => unknown
+```
+
 ## Usage
@@ -55,4 +65,24 @@
 
+Also works nicely with React components as you can have the values lazily evaluated by wrapping it in a function:
+
+```jsx
+import cond from 'cond-flow'
+
+const Component = ({ isDisabled, isNew, isLoading }) => (
+  <>
+    {cond([
+      [isLoading, () => <Loading />],
+      [isNew, () => <Create />],
+      [isDisabled, null]
+    ])}
+  </>
+)
+```
+
+### Note
+
+As all predicates have to be evaluated before the right branch can be chosen, it can have a negative performance impact if you rely on heavy computations here. It's best have simple booleans and resort to `_.cond` for complex use cases.
+
 ## Development
 
 If you find this useful or would like to add features, feel free to clone the repository and open a PR.

src/index.js

@@ -10,5 +10,7 @@ const defaults = {
 
-  return match ? match[1] : null
+  if (!match) return null
+
+  return typeof match[1] === 'function' ? match[1]() : match[1]
 }
 
 module.exports = cond

src/index.spec.js

@@ -36,1 +36,14 @@ const cond = require('./index')
 })
+
+test('Accepts functions as value for lazy evaluation', () => {
+  const falseSpy = jest.fn(() => 'false').mockName('falseHandler')
+  const trueSpy = jest.fn(() => 'true').mockName('trueHandler')
+
+  const value = cond([
+    [false, falseSpy],
+    [true, trueSpy]
+  ])
+
+  expect(falseSpy).not.toHaveBeenCalled()
+  expect(value).toBe('true')
+})

No alert changes

Improved metrics

Total package byte prevSize

178871

increased by0.83%

Number of package files

8

increased by14.29%

Lines of code

50

increased by28.21%

Number of lines in readme file

87

increased by52.63%

No dependency changes