Build: Correct code indentations based on jQuery Style Guide

1. Correct code indentations based on jQuery Style Guide
   (contribute.jquery.org/style-guide/js/#spacing).
2. Add rules to "src/.eslintrc.json" to enable "enforcing consistent
   indentation", with minimal changes to the current code.

Closes gh-4672

16 files changed, 60 insertions, 42 deletions

diff --git a/src/.eslintrc.json b/src/.eslintrc.json
index 4ac59e28b..0c1f3f8a7 100644
--- a/src/.eslintrc.json
+++ b/src/.eslintrc.json
@@ -12,7 +12,10 @@
 
 	"rules": {
 		"import/extensions": [ "error", "always" ],
-		"import/no-cycle": "error"
+		"import/no-cycle": "error",
+		"indent": [ "error", "tab", {
+			"outerIIFEBody": 0
+		} ]
 	},
 
 	"overrides": [
@@ -23,7 +26,17 @@
 				"sourceType": "script"
 			},
 			"rules": {
-				"no-unused-vars": "off"
+				"no-unused-vars": "off",
+				"indent": [ "error", "tab", {
+
+					// Unlike other codes, "wrapper.js" is implemented in UMD.
+					// So it required a specific exception for jQuery's UMD
+					// Code Style. This makes that indentation check is not
+					// performed for 1 depth of outer FunctionExpressions
+					"ignoredNodes": [
+						"Program > ExpressionStatement > CallExpression > FunctionExpression > *"
+					]
+				} ]
 			},
 			"globals": {
 				"jQuery": false,
diff --git a/src/ajax.js b/src/ajax.js
index 0563c924b..61079883e 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -45,7 +45,8 @@ var
 
 	// Anchor tag for parsing the document origin
 	originAnchor = document.createElement( "a" );
-	originAnchor.href = location.href;
+
+originAnchor.href = location.href;
 
 // Base "constructor" for jQuery.ajaxPrefilter and jQuery.ajaxTransport
 function addToPrefiltersOrTransports( structure ) {
@@ -426,8 +427,8 @@ jQuery.extend( {
 			// Context for global events is callbackContext if it is a DOM node or jQuery collection
 			globalEventContext = s.context &&
 				( callbackContext.nodeType || callbackContext.jquery ) ?
-					jQuery( callbackContext ) :
-					jQuery.event,
+				jQuery( callbackContext ) :
+				jQuery.event,
 
 			// Deferreds
 			deferred = jQuery.Deferred(),
diff --git a/src/ajax/xhr.js b/src/ajax/xhr.js
index f6bd52337..2c9bc8125 100644
--- a/src/ajax/xhr.js
+++ b/src/ajax/xhr.js
@@ -8,9 +8,9 @@ jQuery.ajaxSettings.xhr = function() {
 
 var xhrSuccessStatus = {
 
-		// File protocol always yields status code 0, assume 200
-		0: 200
-	};
+	// File protocol always yields status code 0, assume 200
+	0: 200
+};
 
 jQuery.ajaxTransport( function( options ) {
 	var callback;
diff --git a/src/attributes/classes.js b/src/attributes/classes.js
index e020aa5cf..dcd8ad059 100644
--- a/src/attributes/classes.js
+++ b/src/attributes/classes.js
@@ -155,8 +155,8 @@ jQuery.fn.extend( {
 				if ( this.setAttribute ) {
 					this.setAttribute( "class",
 						className || value === false ?
-						"" :
-						dataPriv.get( this, "__className__" ) || ""
+							"" :
+							dataPriv.get( this, "__className__" ) || ""
 					);
 				}
 			}
@@ -171,7 +171,7 @@ jQuery.fn.extend( {
 		while ( ( elem = this[ i++ ] ) ) {
 			if ( elem.nodeType === 1 &&
 				( " " + stripAndCollapse( getClass( elem ) ) + " " ).indexOf( className ) > -1 ) {
-					return true;
+				return true;
 			}
 		}
 
diff --git a/src/core.js b/src/core.js
index d05d84888..ccc5389c5 100644
--- a/src/core.js
+++ b/src/core.js
@@ -303,7 +303,7 @@ jQuery.extend( {
 			if ( isArrayLike( Object( arr ) ) ) {
 				jQuery.merge( ret,
 					typeof arr === "string" ?
-					[ arr ] : arr
+						[ arr ] : arr
 				);
 			} else {
 				push.call( ret, arr );
@@ -405,9 +405,9 @@ if ( typeof Symbol === "function" ) {
 
 // Populate the class2type map
 jQuery.each( "Boolean Number String Function Array Date RegExp Object Error Symbol".split( " " ),
-function( _i, name ) {
-	class2type[ "[object " + name + "]" ] = name.toLowerCase();
-} );
+	function( _i, name ) {
+		class2type[ "[object " + name + "]" ] = name.toLowerCase();
+	} );
 
 function isArrayLike( obj ) {
 
diff --git a/src/core/access.js b/src/core/access.js
index 4eaec4695..6b717b9ba 100644
--- a/src/core/access.js
+++ b/src/core/access.js
@@ -43,8 +43,8 @@ var access = function( elems, fn, key, value, chainable, emptyGet, raw ) {
 			for ( ; i < len; i++ ) {
 				fn(
 					elems[ i ], key, raw ?
-					value :
-					value.call( elems[ i ], i, fn( elems[ i ], key ) )
+						value :
+						value.call( elems[ i ], i, fn( elems[ i ], key ) )
 				);
 			}
 		}
diff --git a/src/core/nodeName.js b/src/core/nodeName.js
index d10e484bc..7d38916b7 100644
--- a/src/core/nodeName.js
+++ b/src/core/nodeName.js
@@ -1,6 +1,6 @@
 function nodeName( elem, name ) {
 
-  return elem.nodeName && elem.nodeName.toLowerCase() === name.toLowerCase();
+	return elem.nodeName && elem.nodeName.toLowerCase() === name.toLowerCase();
 
 };
 
diff --git a/src/css.js b/src/css.js
index 2bffa9610..8c4070c71 100644
--- a/src/css.js
+++ b/src/css.js
@@ -320,10 +320,10 @@ jQuery.each( [ "height", "width" ], function( _i, dimension ) {
 					// Running getBoundingClientRect on a disconnected node
 					// in IE throws an error.
 					( !elem.getClientRects().length || !elem.getBoundingClientRect().width ) ?
-						swap( elem, cssShow, function() {
-							return getWidthOrHeight( elem, dimension, extra );
-						} ) :
-						getWidthOrHeight( elem, dimension, extra );
+					swap( elem, cssShow, function() {
+						return getWidthOrHeight( elem, dimension, extra );
+					} ) :
+					getWidthOrHeight( elem, dimension, extra );
 			}
 		},
 
diff --git a/src/deprecated/event.js b/src/deprecated/event.js
index 7ad4492f0..84ff5bad0 100644
--- a/src/deprecated/event.js
+++ b/src/deprecated/event.js
@@ -28,7 +28,8 @@ jQuery.fn.extend( {
 	}
 } );
 
-jQuery.each( ( "blur focus focusin focusout resize scroll click dblclick " +
+jQuery.each(
+	( "blur focus focusin focusout resize scroll click dblclick " +
 	"mousedown mouseup mousemove mouseover mouseout mouseenter mouseleave " +
 	"change select submit keydown keypress keyup contextmenu" ).split( " " ),
 	function( _i, name ) {
@@ -39,4 +40,5 @@ jQuery.each( ( "blur focus focusin focusout resize scroll click dblclick " +
 				this.on( name, null, data, fn ) :
 				this.trigger( name );
 		};
-	} );
+	}
+);
diff --git a/src/dimensions.js b/src/dimensions.js
index 6f1bf7d2f..42e445362 100644
--- a/src/dimensions.js
+++ b/src/dimensions.js
@@ -6,8 +6,11 @@ import "./css.js";
 
 // Create innerHeight, innerWidth, height, width, outerHeight and outerWidth methods
 jQuery.each( { Height: "height", Width: "width" }, function( name, type ) {
-	jQuery.each( { padding: "inner" + name, content: type, "": "outer" + name },
-		function( defaultExtra, funcName ) {
+	jQuery.each( {
+		padding: "inner" + name,
+		content: type,
+		"": "outer" + name
+	}, function( defaultExtra, funcName ) {
 
 		// Margin is only for outerHeight, outerWidth
 		jQuery.fn[ funcName ] = function( margin, value ) {
diff --git a/src/effects.js b/src/effects.js
index 030d3c7ba..f94da06a9 100644
--- a/src/effects.js
+++ b/src/effects.js
@@ -338,7 +338,7 @@ function Animation( elem, properties, options ) {
 			tweens: [],
 			createTween: function( prop, end ) {
 				var tween = jQuery.Tween( elem, animation.opts, prop, end,
-						animation.opts.specialEasing[ prop ] || animation.opts.easing );
+					animation.opts.specialEasing[ prop ] || animation.opts.easing );
 				animation.tweens.push( tween );
 				return tween;
 			},
@@ -511,7 +511,8 @@ jQuery.fn.extend( {
 					anim.stop( true );
 				}
 			};
-			doAnimation.finish = doAnimation;
+
+		doAnimation.finish = doAnimation;
 
 		return empty || optall.queue === false ?
 			this.each( doAnimation ) :
diff --git a/src/effects/Tween.js b/src/effects/Tween.js
index 9a75a9af2..c0220bd10 100644
--- a/src/effects/Tween.js
+++ b/src/effects/Tween.js
@@ -84,7 +84,7 @@ Tween.propHooks = {
 			if ( jQuery.fx.step[ tween.prop ] ) {
 				jQuery.fx.step[ tween.prop ]( tween );
 			} else if ( tween.elem.nodeType === 1 && (
-					jQuery.cssHooks[ tween.prop ] ||
+				jQuery.cssHooks[ tween.prop ] ||
 					tween.elem.style[ finalPropName( tween.prop ) ] != null ) ) {
 				jQuery.style( tween.elem, tween.prop, tween.now + tween.unit );
 			} else {
diff --git a/src/event.js b/src/event.js
index c7812508b..96056a138 100644
--- a/src/event.js
+++ b/src/event.js
@@ -295,8 +295,8 @@ jQuery.event = {
 			event = jQuery.event.fix( nativeEvent ),
 
 			handlers = (
-					dataPriv.get( this, "events" ) || Object.create( null )
-				)[ event.type ] || [],
+				dataPriv.get( this, "events" ) || Object.create( null )
+			)[ event.type ] || [],
 			special = jQuery.event.special[ event.type ] || {};
 
 		// Use the fix-ed jQuery.Event rather than the (read-only) native event
@@ -416,12 +416,12 @@ jQuery.event = {
 			get: typeof hook === "function" ?
 				function() {
 					if ( this.originalEvent ) {
-							return hook( this.originalEvent );
+						return hook( this.originalEvent );
 					}
 				} :
 				function() {
 					if ( this.originalEvent ) {
-							return this.originalEvent[ name ];
+						return this.originalEvent[ name ];
 					}
 				},
 
diff --git a/src/event/trigger.js b/src/event/trigger.js
index 0d1cd4c56..f36000af7 100644
--- a/src/event/trigger.js
+++ b/src/event/trigger.js
@@ -99,9 +99,7 @@ jQuery.extend( jQuery.event, {
 				special.bindType || type;
 
 			// jQuery handler
-			handle = (
-					dataPriv.get( cur, "events" ) || Object.create( null )
-				)[ event.type ] &&
+			handle = ( dataPriv.get( cur, "events" ) || Object.create( null ) )[ event.type ] &&
 				dataPriv.get( cur, "handle" );
 			if ( handle ) {
 				handle.apply( cur, data );
diff --git a/src/selector.js b/src/selector.js
index 66abe7935..0d80c6fd3 100644
--- a/src/selector.js
+++ b/src/selector.js
@@ -602,9 +602,11 @@ Expr = jQuery.expr = {
 		TAG: function( nodeNameSelector ) {
 			var expectedNodeName = nodeNameSelector.replace( runescape, funescape ).toLowerCase();
 			return nodeNameSelector === "*" ?
+
 				function() {
- return true;
-} :
+					return true;
+				} :
+
 				function( elem ) {
 					return nodeName( elem, expectedNodeName );
 				};
diff --git a/src/serialize.js b/src/serialize.js
index a25097edc..ebe733450 100644
--- a/src/serialize.js
+++ b/src/serialize.js
@@ -101,16 +101,14 @@ jQuery.fn.extend( {
 			// Can add propHook for "elements" to filter or add form elements
 			var elements = jQuery.prop( this, "elements" );
 			return elements ? jQuery.makeArray( elements ) : this;
-		} )
-		.filter( function() {
+		} ).filter( function() {
 			var type = this.type;
 
 			// Use .is( ":disabled" ) so that fieldset[disabled] works
 			return this.name && !jQuery( this ).is( ":disabled" ) &&
 				rsubmittable.test( this.nodeName ) && !rsubmitterTypes.test( type ) &&
 				( this.checked || !rcheckableType.test( type ) );
-		} )
-		.map( function( _i, elem ) {
+		} ).map( function( _i, elem ) {
 			var val = jQuery( this ).val();
 
 			if ( val == null ) {