Document getInitialProps error

errors/get-inital-props-as-an-instance-method.md

@@ -0,0 +1,39 @@
+# getInitialProps was defined as an instance method
+
+#### Why This Error Occurred
+
+`getInitialProps` must be a static method in order to be called by next.js.
+
+#### Possible Ways to Fix It
+
+Use the static keyword.
+
+```js
+export default class YourEntryComponent extends React.Component {
+  static getInitialProps () {
+    return {}
+  }
+
+  render () {
+    return 'foo'
+  }
+}
+```
+
+or
+
+```js
+const YourEntryComponent = function () {
+  return 'foo'
+}
+
+YourEntryComponent.getInitialProps = () => {
+  return {}
+}
+
+export default YourEntryComponent
+```
+
+### Useful Links
+
+- [Fetching data and component lifecycle](https://github.com/zeit/next.js#fetching-data-and-component-lifecycle)

lib/utils.js

@@ -57,7 +57,7 @@ export async function loadGetInitialProps (Component, ctx) {
   if (process.env.NODE_ENV !== 'production') {
     if (Component.prototype && Component.prototype.getInitialProps) {
       const compName = getDisplayName(Component)
-      const message = `"${compName}.getInitialProps()" is defined as an instance method.`
+      const message = `"${compName}.getInitialProps()" is defined as an instance method - visit https://err.sh/next.js/get-inital-props-as-an-instance-method for more information.`
       throw new Error(message)
     }
   }