Merge pull request #165 from trufflesuite/feature/tests

Feature/tests

.eslintrc

@@ -1,3 +1,10 @@
 {
-  "extends": ["standard"]
-}
+  "extends": ["standard", "plugin:jest/recommended"],
+  "plugins": ["jest"],
+  "rules": {
+    "jest/prefer-to-have-length": "warn",
+  },
+  "env" : {
+  	"jest/globals": true
+  }
+}

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-.DS_Store
+.DS_Store
+.tern-project

CONTRIBUTING.md

@@ -29,14 +29,16 @@ How Can I Contribute?
 
 All contributions are welcome!
 
-If you run into an issue, the first step is to reach out in [our community Gitter channel](https://gitter.im/ConsenSys/truffle),
-in case others have run into the problem or know how to help.
+If you run into an issue, the first step is to reach out in [our community
+Gitter channel](https://gitter.im/ConsenSys/truffle), in case others have run
+into the problem or know how to help.
 
-To report a problem or to suggest a new feature, [open a GitHub Issue](https://github.com/trufflesuite/drizzle/issues/new).
-This will help the Drizzle maintainers become aware of the problem and prioritize
-a fix.
+To report a problem or to suggest a new feature, [open a GitHub
+Issue](https://github.com/trufflesuite/drizzle/issues/new).  This will help the
+Drizzle maintainers become aware of the problem and prioritize a fix.
 
-For code contributions, for either new features or bug fixes, see [Development](#development).
+For code contributions, for either new features or bug fixes, see
+[Development](#development).
 
 If you're looking to make a substantial change, you may want to reach out first
 to give us a heads up.
@@ -47,13 +49,17 @@ Development
 
 ### Overview
 
-Drizzle has two companion libraries ([`drizzle-react`](https://github.com/trufflesuite/drizzle-react) and [`drizzle-react-components`](https://github.com/trufflesuite/drizzle-react-components)), each with their own
-NPM packages.
+Drizzle has two companion libraries
+([`drizzle-react`](https://github.com/trufflesuite/drizzle-react) and
+[`drizzle-react-components`](https://github.com/trufflesuite/drizzle-react-components)),
+each with their own NPM packages.
 
 The content of this guide applies to those companion libraries as well.
 
-This repository ([trufflesuite/drizzle](https://github.com/trufflesuite/drizzle))
-contains the core logic for storing and updating chaindata in a [Redux](https://github.com/reduxjs/redux) store.
+This repository
+([trufflesuite/drizzle](https://github.com/trufflesuite/drizzle)) contains the
+core logic for storing and updating chaindata in a
+[Redux](https://github.com/reduxjs/redux) store.
 
 ### Development Requirements
 
@@ -69,8 +75,9 @@ First clone this repository and install NPM dependencies:
     $ git clone [email protected]:trufflesuite/drizzle.git
     $ cd drizzle
     $ npm install
+    $ npm test
 
-Then, run the build command :
+If all is good, then run the build command :
 
     $ npm run build
 
@@ -87,11 +94,12 @@ You're ready to use your local developement version of Drizzle in your project.
 
 ### Forks, Branches, and Pull Requests
 
-Community contributions to Drizzle require that you first fork the
-repositor(y|ies) you are modifying. After your modifications, push changes to
+Community contributions to Drizzle require that you first fork each
+repository you wish to modify. After your modifications, push changes to
 your fork(s) and submit a pull request upstream to `trufflesuite`'s fork(s).
 
-See GitHub documentation about [Collaborating with issues and pull requests](https://help.github.com/categories/collaborating-with-issues-and-pull-requests/)
+See GitHub documentation about [Collaborating with issues and pull
+requests](https://help.github.com/categories/collaborating-with-issues-and-pull-requests/)
 for more information.
 
 > :exclamation: **Note:** _Drizzle development uses a long-lived `develop` branch for new (non-hotfix)

jest.config.js

@@ -0,0 +1,17 @@
+// For a detailed explanation regarding each configuration property, visit:
+// https://jestjs.io/docs/en/configuration.html
+
+module.exports = {
+  // Automatically clear mock calls and instances between every test
+  clearMocks: true,
+
+  // An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
+  modulePathIgnorePatterns: ['<rootDir>[/\\\\](dist|node_modules)[/\\\\]'],
+
+  // The test environment that will be used for testing
+  testEnvironment: '<rootDir>/test/environments/ganache-environment.js',
+
+  transform: {
+    '^.+\\.js': '<rootDir>/jest.transform.js'
+  }
+}

jest.transform.js

@@ -0,0 +1,8 @@
+const babelJest = require('babel-jest')
+const webpackConfig = require('./webpack/base.config')
+
+/* Jest needs to know how to transform our source.  Use the same transformation
+ * options/rules specified in webpack configuration.
+ */
+const { options: babelOptions } = webpackConfig.module.rules[0]
+module.exports = babelJest.createTransformer(babelOptions)