MyEtherWallet V4+ (ALPHA - VISIT V3 for the production site)

Run:

npm run dev # run app in dev mode

Build:

npm run build # build app

It generates app in dist folder.

Unit Tests:

npm run test # run tests with Jest

Integration Tests:

npm run test:int # run tests with Jest

Dev (HTTPS):

1. Create your own SSL Certificate (Heroku has a nice guide here)
2. Move the .key and .crt files into webpack_config/server.*
3. Run the following command:

npm run dev:https

Address Derivation Checker:

EthereumJS-Util previously contained a bug that would incorrectly derive addresses from private keys with a 1/128 probability of occurring. A summary of this issue can be found here.

As a reactionary measure, the address derivation checker was created.

To test for correct address derivation, the address derivation checker uses multiple sources of address derivation (EthereumJS and PyEthereum) to ensure that multiple official implementations derive the same address for any given private key.

The derivation checker utility assumes that you have:

1. Docker installed/available
2. dternyak/eth-priv-to-addr pulled from DockerHub

Docker setup instructions:

1. Install docker (on macOS, Docker for Mac is suggested)
2. docker pull dternyak/eth-priv-to-addr

Run Derivation Checker

The derivation checker utility runs as part of the integration test suite.

npm run test:int

Folder structure:

│
├── common
│   ├── actions - application actions
│   ├── api - Services and XHR utils
│   ├── components - components according to "Redux philosophy"
│   ├── config - frontend config depending on REACT_WEBPACK_ENV
│   ├── containers - containers according to "Redux philosophy"
│   ├── reducers - application reducers
│   ├── routing - application routing
│   ├── index.tsx - entry
│   ├── index.html
├── static
├── webpack_config - Webpack configuration
├── jest_config - Jest configuration

Style Guides and Philosophies

The following are guides for developers to follow for writing compliant code.

Redux and Actions

Each reducer has one file in reducers/[namespace].ts that contains the reducer and initial state, one file in actions/[namespace].ts that contains the action creators and their return types, and optionally one file in sagas/[namespace].ts that handles action side effects using redux-saga.

The files should be laid out as follows:

Reducer

• State should be explicitly defined and exported
• Initial state should match state typing, define every key

import { NamespaceAction } from "actions/[namespace]";
import { TypeKeys } from 'actions/[namespace]/constants';

export interface State { /* definition for state object */ };
export const INITIAL_STATE: State = { /* Initial state shape */ };

export function [namespace](
	state: State = INITIAL_STATE,
	action: NamespaceAction
): State {
	switch (action.type) {
		case TypeKeys.NAMESPACE_NAME_OF_ACTION:
			return {
				...state,
				// Alterations to state
			};
		default:
			return state;
	}
}

Actions

• Define each action creator in actionCreator.ts
• Define each action object type in actionTypes.ts
  • Export a union of all of the action types for use by the reducer
• Define each action type as a string enum in constants.ts
• Export actionCreators and actionTypes from module file index.ts

├── common
    ├── actions - application actions
        ├── [namespace] - action namespace
            ├── actionCreators.ts - action creators
            ├── actionTypes.ts - action interfaces / types
            ├── constants.ts - string enum
            ├── index.ts - exports all action creators and action object types

constants.ts

export enum TypeKeys {
  NAMESPACE_NAME_OF_ACTION = 'NAMESPACE_NAME_OF_ACTION'
}

actionTypes.ts

/*** Name of action ***/
export interface NameOfActionAction {
  type: TypeKeys.NAMESPACE_NAME_OF_ACTION;
  /* Rest of the action object shape */
}

/*** Action Union ***/
export type NamespaceAction = ActionOneAction | ActionTwoAction | ActionThreeAction;

actionCreators.ts

import * as interfaces from './actionTypes';
import { TypeKeys } from './constants';

export interface TNameOfAction = typeof nameOfAction;
export function nameOfAction(): interfaces.NameOfActionAction {
	return {
		type: TypeKeys.NAMESPACE_NAME_OF_ACTION,
		payload: {}
	};
};

index.ts

export * from './actionCreators';
export * from './actionTypes';

Typing Redux-Connected Components

Components that receive props directly from redux as a result of the connect function should use AppState for typing, rather than manually defining types. This makes refactoring reducers easier by catching mismatches or changes of types in components, and reduces the chance for inconsistency. It's also less code overall.

// Do this
import { AppState } from 'reducers';

interface Props {
	wallet: AppState['wallet']['inst'];
	rates: AppState['rates']['rates'];
	// ...
}

// Not this
import { IWallet } from 'libs/wallet';
import { Rates } from 'libs/rates';

interface Props {
	wallet: IWallet;
	rates: Rates;
	// ...
}

However, if you have a sub-component that takes in props from a connected component, it's OK to manually specify the type. Especially if you go from being type-or-null to guaranteeing the prop will be passed (because of a conditional render.)

Higher Order Components

Typing Injected Props

Props made available through higher order components can be tricky to type. You can inherit the injected props, and in the case of react router, specialize the generic in withRouter so it can omit all of its injected props from the component.

import { RouteComponentProps } from 'react-router-dom';

interface MyComponentProps extends RouteComponentProps<{}> {
  name: string;
  countryCode?: string;
}

class MyComponent extends React.Component<MyComponentProps, {}> {

  render() {
    const { name, countryCode, location } = this.props; // location being the one of the injected props from the withRouter HOC
    ...
  }
}

export default withRouter<Props>(MyComponent);

Event Handlers

Event handlers such as onChange and onClick, should be properly typed. For example, if you have an event listener on an input element inside a form:

public onValueChange = (e: React.FormEvent<HTMLInputElement>) => {
    if (this.props.onChange) {
      this.props.onChange(
        e.currentTarget.value,
        this.props.unit
      );
    }
  };

Where you type the event as a React.FormEvent of type HTML<TYPE>Element.

Class names

Dynamic class names should use the classnames module to simplify how they are created instead of using string template literals with expressions inside.

Styling

Legacy styles are housed under common/assets/styles and written with LESS. However, going forward, each styled component should create a a .scss file of the same name in the same folder, and import it like so:

import React from 'react';

import './MyComponent.scss';

export default class MyComponent extends React.component<{}, {}> {
  render() {
    return (
      <div className="MyComponent">
        <div className="MyComponent-child">Hello!</div>
      </div>
    );
  }
}

These style modules adhere to SuitCSS naming convention:

.MyComponent {
  /* Styles */

  &-child {
    /* Styles */

    &.is-hidden {
      display: none;
    }
  }
}

All elements inside of a component should extend its parent class namespace, or create a new namespace (Potentially breaking that out into its own component.)

Variables and mixins can be imported from the files in common/styles:

@import 'sass/colors';

code {
  color: $code-color;
}

Converting Styles

When working on a module that has styling in Less, try to do the following:

• Screenshot the component in question
• Create a new SCSS file in the same directory
• Remove styling from LESS file, convert it to the SCSS file (Mostly s/@/$)
• Convert class names to SuitCSS naming convention
• Convert any utility classes from etherewallet-utilities.less into mixins
• Convert as many element selectors to class name selectors as possible
• Convert as many <br/> tags or  s to margins
• Ensure that there has been little to no deviation from screenshot

Adding Icon-fonts

1. Download chosen icon-font
2. Declare css font-family:

   @font-face {
   	font-family: 'social-media';
   	src: url('../assets/fonts/social-media.eot');
   	src: url('../assets/fonts/social-media.eot') format('embedded-opentype'),
   		url('../assets/fonts/social-media.woff2') format('woff2'),
   		url('../assets/fonts/social-media.woff') format('woff'),
   		url('../assets/fonts/social-media.ttf') format('truetype'),
   		url('../assets/fonts/social-media.svg') format('svg');
   	font-weight: normal;
   	font-style: normal;
   }
   

3. Create classes for each icon using their unicode character

   .sm-logo-facebook:before {
       content: '\ea02';
     }
   

   • How to get unicode icon values?
4. Write some markup:

   <a href="/">
   	<i className={`sm-icon sm-logo-${text} sm-24px`} />
   	Hello World
   </a>
   

Thanks & Support

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