Slim down the travis script, add js checks and fix js errors thrown up.

What it will now do:
- Lint the php files against relevant PHP versions.
- Lint the js files once - the result won't change across PHP versions.
- Check against WPCS once - the result won't change across PHP versions.

What I have changed:
- Added linting against PHP 7 and HHVM, with HHVM being allowed to fail.
- Added js linting and style check per example from Twenty Sixteen.
- Moved to the faster container based environment for running travis.
- Script will no longer pull in PHPCS, WPCS and the JS linters in every build. Now they will only be pulled in when needed.
- Limited the clone depth for quicker cloning of external repositories.
- Removed the pulling in of WP and running builds against different WP versions as this wasn't used at all in the actual test scripts.

.jscsrc

@@ -0,0 +1,7 @@
+{
+    "preset": "wordpress",
+    "fileExtensions": [ ".js" ],
+    "excludeFiles": [
+    	"js/skip-link-focus-fix.js"
+    ]
+}

.jshintignore

@@ -0,0 +1,2 @@
+js/skip-link-focus-fix.js
+**.min.js

.jshintrc

@@ -0,0 +1,26 @@
+{
+	"boss": true,
+	"curly": true,
+	"eqeqeq": true,
+	"eqnull": true,
+	"es3": true,
+	"expr": true,
+	"immed": true,
+	"noarg": true,
+	"nonbsp": true,
+	"onevar": true,
+	"quotmark": "single",
+	"trailing": true,
+	"undef": true,
+	"unused": true,
+
+	"browser": true,
+
+	"globals": {
+		"_": false,
+		"Backbone": false,
+		"jQuery": false,
+		"JSON": false,
+		"wp": false
+	}
+}

.travis.yml

@@ -4,48 +4,41 @@
 # For use with the Underscores WordPress theme.
 # @link https://github.com/Automattic/_s
 
+# Ditch sudo and use containers.
+# @link http://docs.travis-ci.com/user/migrating-from-legacy/#Why-migrate-to-container-based-infrastructure%3F
+# @link http://docs.travis-ci.com/user/workers/container-based-infrastructure/#Routing-your-build-to-container-based-infrastructure
+sudo: false
+
 # Declare project language.
 # @link http://about.travis-ci.org/docs/user/languages/php/
 language: php
 
 # Declare versions of PHP to use. Use one decimal max.
-php:
-  # aliased to a recent 5.5.x version
-  - "5.5"
-  # aliased to a recent 5.4.x version
-  - "5.4"
-  # aliased to a recent 5.3.x version
-  - "5.3"
-  # Current $required_php_version for WordPress: 5.2.4
-  - "5.2"
-
-# Declare which versions of WordPress to test against.
-# Also declare whether or not to test in Multisite.
-env:
-  # Trunk
-  # @link https://github.com/WordPress/WordPress
-  - WP_VERSION=master WP_MULTISITE=0
-  - WP_VERSION=master WP_MULTISITE=1
-  # WordPress 4.2
-  # @link https://github.com/WordPress/WordPress/tree/4.2-branch
-  - WP_VERSION=4.2 WP_MULTISITE=0
-  - WP_VERSION=4.2 WP_MULTISITE=1
-  # WordPress 4.1
-  # @link https://github.com/WordPress/WordPress/tree/4.1-branch
-  - WP_VERSION=4.1 WP_MULTISITE=0
-  - WP_VERSION=4.1 WP_MULTISITE=1
-
-# Declare 5.6 beta in test matrix.
-# @link https://buddypress.trac.wordpress.org/ticket/5620
 # @link http://docs.travis-ci.com/user/build-configuration/
 matrix:
-  include:
-    - php: 5.6
-      env: WP_VERSION=master
-  allow_failures:
-    - php: 5.6
     fast_finish: true
 
+    include:
+        # Current $required_php_version for WordPress: 5.2.4
+        # aliased to 5.2.17
+        - php: '5.2'
+        # aliased to 5.3.29
+        - php: '5.3'
+        # aliased to a recent 5.4.x version
+        - php: '5.4'
+        # aliased to a recent 5.5.x version
+        - php: '5.5'
+          env: SNIFF=1
+        # aliased to a recent 5.6.x version
+        - php: '5.6'
+        # aliased to a recent 7.x version
+        - php: '7.0'
+        # aliased to a recent hhvm version
+        - php: 'hhvm'
+
+    allow_failures:
+        - php: 'hhvm'
+
 # Use this to prepare the system to install prerequisites or dependencies.
 # e.g. sudo apt-get update.
 # Failures in this section will result in build status 'errored'.
@@ -55,46 +48,35 @@ matrix:
 # e.g. copy database configurations, environment variables, etc.
 # Failures in this section will result in build status 'errored'.
 before_script:
-  # Set up WordPress installation.
+    - export PHPCS_DIR=/tmp/phpcs
-  - export WP_DEVELOP_DIR=/tmp/wordpress/
+    - export WPCS_DIR=/tmp/wpcs
-  - mkdir -p $WP_DEVELOP_DIR
-  # Use the Git mirror of WordPress.
-  - git clone --depth=1 --branch="$WP_VERSION" git://develop.git.wordpress.org/ $WP_DEVELOP_DIR
-  # Set up theme information.
-  - theme_slug=$(basename $(pwd))
-  - theme_dir=$WP_DEVELOP_DIR/src/wp-content/themes/$theme_slug
-  - cd ..
-  - mv $theme_slug $theme_dir
-  # Set up WordPress configuration.
-  - cd $WP_DEVELOP_DIR
-  - echo $WP_DEVELOP_DIR
-  - cp wp-tests-config-sample.php wp-tests-config.php
-  - sed -i "s/youremptytestdbnamehere/wordpress_test/" wp-tests-config.php
-  - sed -i "s/yourusernamehere/root/" wp-tests-config.php
-  - sed -i "s/yourpasswordhere//" wp-tests-config.php
-  # Create WordPress database.
-  - mysql -e 'CREATE DATABASE wordpress_test;' -uroot
     # Install CodeSniffer for WordPress Coding Standards checks.
-  - git clone https://github.com/squizlabs/PHP_CodeSniffer.git php-codesniffer
+    - if [[ "$SNIFF" == "1" ]]; then git clone -b master --depth 1 https://github.com/squizlabs/PHP_CodeSniffer.git $PHPCS_DIR; fi
     # Install WordPress Coding Standards.
-  - git clone https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards.git wordpress-coding-standards
+    - if [[ "$SNIFF" == "1" ]]; then git clone -b master --depth 1 https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards.git $WPCS_DIR; fi
-  # Hop into CodeSniffer directory.
-  - cd php-codesniffer
     # Set install path for WordPress Coding Standards.
     # @link https://github.com/squizlabs/PHP_CodeSniffer/blob/4237c2fc98cc838730b76ee9cee316f99286a2a7/CodeSniffer.php#L1941
-  - scripts/phpcs --config-set installed_paths ../wordpress-coding-standards
+    - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/scripts/phpcs --config-set installed_paths $WPCS_DIR; fi
-  # Hop into themes directory.
-  - cd $theme_dir
     # After CodeSniffer install you should refresh your path.
-  - phpenv rehash
+    - if [[ "$SNIFF" == "1" ]]; then phpenv rehash; fi
+    # Install JSCS: JavaScript Code Style checker
+    # @link http://jscs.info/
+    - if [[ "$SNIFF" == "1" ]]; then npm install -g jscs; fi
+    # Install JSHint, a JavaScript Code Quality Tool
+    # @link http://jshint.com/docs/
+    - if [[ "$SNIFF" == "1" ]]; then npm install -g jshint; fi
 
 # Run test script commands.
 # Default is specific to project language.
 # All commands must exit with code 0 on success. Anything else is considered failure.
 script:
     # Search for PHP syntax errors.
-  - find . \( -name '*.php' \) -exec php -lf {} \;
+    - find -L . -name '*.php' -print0 | xargs -0 -n 1 -P 4 php -l
-  # WordPress Coding Standards
+    # Run the theme through JSHint.
+    - if [[ "$SNIFF" == "1" ]]; then jshint .; fi
+    # Run the theme through JavaScript Code Style checker.
+    - if [[ "$SNIFF" == "1" ]]; then jscs .; fi
+    # WordPress Coding Standards.
     # @link https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards
     # @link http://pear.php.net/package/PHP_CodeSniffer/
     # -p flag: Show progress of the run.
@@ -103,7 +85,7 @@ script:
     # -n flag: Do not print warnings. (shortcut for --warning-severity=0)
     # --standard: Use WordPress as the standard.
     # --extensions: Only sniff PHP files.
-  - $WP_DEVELOP_DIR/php-codesniffer/scripts/phpcs -p -s -v -n . --standard=./codesniffer.ruleset.xml --extensions=php
+    - if [[ "$SNIFF" == "1" ]]; then $PHPCS_DIR/scripts/phpcs -p -s -v -n . --standard=./codesniffer.ruleset.xml --extensions=php; fi
 
 # Receive notifications for build results.
 # @link http://docs.travis-ci.com/user/notifications/#Email-notifications

js/customizer.js

@@ -1,5 +1,5 @@
 /**
- * customizer.js
+ * File customizer.js.
  *
  * Theme Customizer enhancements for a better user experience.
  *
@@ -7,6 +7,7 @@
  */
 
 ( function( $ ) {
+
 	// Site title and description.
 	wp.customize( 'blogname', function( value ) {
 		value.bind( function( to ) {
@@ -18,6 +19,7 @@
 			$( '.site-description' ).text( to );
 		} );
 	} );
+
 	// Header text color.
 	wp.customize( 'header_textcolor', function( value ) {
 		value.bind( function( to ) {

js/navigation.js

@@ -1,11 +1,11 @@
 /**
- * navigation.js
+ * File navigation.js.
  *
  * Handles toggling the navigation menu for small screens and enables tab
  * support for dropdown menus.
  */
 ( function() {
-	var container, button, menu, links, subMenus;
+	var container, button, menu, links, subMenus, i, len;
 
 	container = document.getElementById( 'site-navigation' );
 	if ( ! container ) {
@@ -47,7 +47,7 @@
 	subMenus = menu.getElementsByTagName( 'ul' );
 
 	// Set menu items with submenus to aria-haspopup="true".
-	for ( var i = 0, len = subMenus.length; i < len; i++ ) {
+	for ( i = 0, len = subMenus.length; i < len; i++ ) {
 		subMenus[i].parentNode.setAttribute( 'aria-haspopup', 'true' );
 	}