PHPCS: Add new ruleset to the project

Update .distignore and .gitignore with phpcs/phpunit config files
Update wp-cli-tests to 2.1

.distignore

@@ -6,6 +6,8 @@
 .travis.yml
 behat.yml
 circle.yml
+phpcs.xml.dist
+phpunit.xml.dist
 bin/
 features/
 utils/

.gitignore

@@ -6,3 +6,6 @@ vendor/
 *.tar.gz
 composer.lock
 *.log
+phpunit.xml
+phpcs.xml
+.phpcs.xml

composer.json

@@ -18,7 +18,7 @@
     "require-dev": {
         "wp-cli/entity-command": "^1.3 || ^2",
         "wp-cli/scaffold-command": "^1.2 || ^2",
-        "wp-cli/wp-cli-tests": "^2.0.7"
+        "wp-cli/wp-cli-tests": "^2.1"
     },
     "config": {
         "process-timeout": 7200,

phpcs.xml.dist

@@ -0,0 +1,72 @@
+<?xml version="1.0"?>
+<ruleset name="WP-CLI-extension">
+	<description>Custom ruleset for WP-CLI extension-command</description>
+
+	<!--
+	#############################################################################
+	COMMAND LINE ARGUMENTS
+	For help understanding this file: https://github.com/squizlabs/PHP_CodeSniffer/wiki/Annotated-ruleset.xml
+	For help using PHPCS: https://github.com/squizlabs/PHP_CodeSniffer/wiki/Usage
+	#############################################################################
+	-->
+
+	<!-- What to scan. -->
+	<file>.</file>
+
+	<!-- Ignoring select files/folders.
+		 https://github.com/squizlabs/PHP_CodeSniffer/wiki/Advanced-Usage#ignoring-files-and-folders -->
+	<exclude-pattern>*/node_modules/*</exclude-pattern>
+	<exclude-pattern>*/vendor/*</exclude-pattern>
+
+	<!-- Show progress. -->
+	<arg value="p"/>
+
+	<!-- Strip the filepaths down to the relevant bit. -->
+	<arg name="basepath" value="./"/>
+
+	<!-- Check up to 8 files simultaneously. -->
+	<arg name="parallel" value="8"/>
+
+	<!--
+	#############################################################################
+	USE THE WPCliCS RULESET
+	#############################################################################
+	-->
+
+	<rule ref="WPCliCS"/>
+
+	<!--
+	#############################################################################
+	PROJECT SPECIFIC CONFIGURATION FOR SNIFFS
+	#############################################################################
+	-->
+
+	<!-- For help understanding the `testVersion` configuration setting:
+		 https://github.com/PHPCompatibility/PHPCompatibility#sniffing-your-code-for-compatibility-with-specific-php-versions -->
+	<config name="testVersion" value="5.4-"/>
+
+	<!-- Verify that everything in the global namespace is either namespaced or prefixed.
+		 See: https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards/wiki/Customizable-sniff-properties#naming-conventions-prefix-everything-in-the-global-namespace -->
+	<rule ref="WordPress.NamingConventions.PrefixAllGlobals">
+		<properties>
+			<property name="prefixes" type="array">
+				<element value="WP_CLI\Extension"/><!-- Namespaces. -->
+				<element value="wpcli_extension"/><!-- Global variables and such. -->
+			</property>
+		</properties>
+	</rule>
+
+	<!-- Exclude existing classes from the prefix rule as it would break BC to prefix them now. -->
+	<rule ref="WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedClassFound">
+		<exclude-pattern>*/src/(Plugin_|Theme_(Mod_)?)Command\.php$</exclude-pattern>
+	</rule>
+
+	<rule ref="WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedNamespaceFound">
+		<exclude-pattern>*/src/WP_CLI/Fetchers/(Plugin|Theme)\.php$</exclude-pattern>
+		<exclude-pattern>*/src/WP_CLI/CommandWithUpgrade\.php$</exclude-pattern>
+		<exclude-pattern>*/src/WP_CLI/(CommandWith|DestructivePlugin|DestructiveTheme)Upgrader\.php$</exclude-pattern>
+	</rule>
+
+
+
+</ruleset>