Update README.md

README.md

@@ -5,3 +5,130 @@
 
 # props-check
 Check your props and give a helpful error if you've mis-typed.
+
+## Installation
+
+`npm install props-check`
+
+## Requiring the module
+
+```javascript
+const PropsCheck = require('props-check')
+```
+
+## `PropsCheck`
+
+PropsCheck checks props against the spec and returns a map with list of possible corrections.
+
+```javascript
+// Example spec
+const spec = {
+  read: 'Function'
+, sanitize: '[Function]'
+, validate: '[Function]'
+, normalize: '[Function]'
+};
+
+
+// Example object
+const test = {
+  raed: () => null
+, santize: [ () => null ]
+, alvidate: [ () => null ]
+, normalize: [ () => null ]
+};
+
+
+const result = PropsChecks(spec, test);
+```
+
+result:
+```javascript
+  { raed: [ 'read' ]
+  , santize: [ 'sanitize' ]
+  , alvidate: [ 'validate' ]
+  , normalize: []
+  }
+```
+
+`PropsChecks` returns `null` if spec and test have the exact same props.
+
+## `PropsCheck.custom`
+
+`PropsCheck.custom` takes a custom comparator and returns a function that is similar to PropsCheck.
+
+```javascript
+const comparator = (a, b) => a < b;
+
+const result = PropsCheck.custom(comparator)(spec, test);
+```
+
+## `PropsCheck.human`
+
+`PropsCheck.human` accepts the same arguments as PropsCheck but returns a more helpful error message.
+
+```javascript
+const result = PropsChecks.human(spec, test);
+```
+
+result:
+
+```
+    You gave me this:
+
+      {
+        raed: …,
+        santize: …,
+        alvidate: …,
+        normalize: …
+      }
+
+    I wasn't expecting:
+
+      { raed: …, santize: …, alvidate: … }
+
+    You didn't give me:
+
+      { read: …, sanitize: …, validate: … }
+
+    Here's how to fix it:
+
+      raed <-> read
+      santize <-> sanitize
+      alvidate <-> validate
+```
+
+## `PropsCheck.customHuman`
+
+`PropsCheck.customHuman` takes a custom message map and returns a function that is similar to PropsCheck.human.
+
+```javascript
+const customMessages = {
+  given: [ "This is what I got:", … ]
+, unexpected: [ "Something is not right..", … ]
+, missing: [ "I'm looking for this:", … ]
+, conclusion: [ "I suggest the following changes:", … ]
+};
+
+const result = PropsChecks.customHuman(customMessages)(spec, test);
+```
+
+Custom messages will be used randomly if more than 1 message is provided in the list. If a property of the customMessages is misspelled or if a list is empty, default messages will be used instead.
+
+## Misc things
+
+- If you use `PropsCheck.custom` and provide your own comparator, make sure that the comparator accepts 2 arguments and returns either `0` on equal, `1` on similar, or `-1` on mismatch.
+- All functions are curried. Meaning that the following:
+```javascript
+PropsCheck(spec)(test);
+PropsCheck.custom(comparator)(spec)(test);
+PropsCheck.human(spec)(test);
+PropsCheck.customHuman(customMessages)(spec)(test);
+```
+  are the same as:
+```javascript
+PropsCheck(spec, test);
+PropsCheck.custom(comparator)(spec, test);
+PropsCheck.human(spec, test);
+PropsCheck.customHuman(customMessages)(spec, test);
+```