Add examples of snapshot assertion

.npmignore

@@ -0,0 +1,2 @@
+example/
+docs/

CHANGELOG

@@ -1,4 +1,18 @@
-# CHANGELOG
+# Changelog
+All notable changes to this project will be documented in this file.
 
-## v1.0.0 (30 October 2017)
-Initial release
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [1.0.1] - 2018-02-25
+### Added
+- Example in `/example` to demonstrate how snapshot assertion works
+- Image of assertion test in README
+
+### Changed
+- Changelog format
+- Upgraded to Jest 22 for testing
+
+## [1.0.0] - 2017-10-30
+### Added
+- Initial release

README.md

@@ -6,6 +6,10 @@ Assertion module for Yeoman generators, include comparing file with snapshot.
 
 Extends the `yeoman-assert` module, which itself extends the native `assert` module. You only therefore need to import this assertion library to get all the functionality required for testing your Yeoman generator.
 
+You can see an example of what a failed snapshot assertion looks like below:
+
+![AssertionError for README.md:1 with expected and actual results](./docs/j154004-yeoman-assert.png)
+
 ## Install
 ```
 npm install --save-dev @j154004/yeoman-assert
@@ -14,8 +18,11 @@ npm install --save-dev @j154004/yeoman-assert
 ## Usage
 ```
 const assert = require('@j154004/yeoman-assert');
+const path = require('path');
 ```
 
+See the example generator in `/example` to see how to structure your tests and to see an example output from a failing test.
+
 ## API
 ### `snapshotContent`
 * __filePath__ (String) Path to generated file.
@@ -35,4 +42,4 @@ Snapshot files should be stored in a `snapshot` directory where your tests are r
 ## Licence
 [BSD license](/LICENSE)  Copyright (c) elementsweb
 
-`yeoman-assert` is licensed under BSD-2-Clause Copyright (c) Google
+`yeoman-assert` is licensed under BSD-2-Clause Copyright (c) Google

example/README.md

@@ -0,0 +1,5 @@
+# @j154004/yeoman-assert example
+A simple generator using `@j154004/yeoman-assert` in tests to check output file against a snapshot file.
+
+## Usage
+Run the tests (1 is designed to purposefully fail) with `npm t` to see the snapshot comparison output.

example/generators/app/index.js

@@ -0,0 +1,32 @@
+'use strict';
+const Generator = require('yeoman-generator');
+
+module.exports = class extends Generator {
+  prompting() {
+    const prompts = [{
+      name: 'projectName',
+      message: 'Name for the project',
+    }];
+
+    return this.prompt(prompts).then(function (props) {
+      this.props = props;
+    }.bind(this));
+  }
+
+  writing() {
+    this.fs.copyTpl(
+      this.templatePath('README.md'),
+      this.destinationPath('README.md'),
+      {
+        projectName: this.props.projectName,
+      },
+    );
+  }
+
+  install() {
+    this.installDependencies({
+      bower: false,
+      npm: true,
+    });
+  }
+}

example/generators/app/templates/README.md

@@ -0,0 +1 @@
+# <%= projectName %>