Build: ESLint: forbid unused function parameters

This commit requires all function parameters to be used, not just the last one.
In cases where that's not possible as we need to match an external API, there's
an escape hatch of prefixing an unused argument with `_`.

This change makes it easier to catch unused AMD dependencies and unused
parameters in internal functions the API of which we may change at will, among
other things.

Unused AMD dependencies have been removed as part of this commit.

Closes gh-4381

(cherry-picked from 438b1a3e8a52d3e4efd8aba45498477038849c97)

diff --git a/build/tasks/build.js b/build/tasks/build.js
index b59ef816ecb1ac56685d8a135775cf027292099d..73dfd581d146c5253e679f3036432d823c0288e4 100644 (file)
--- a/build/tasks/build.js
+++ b/build/tasks/build.js
@@ -372,7 +372,7 @@ module.exports = function( grunt ) {
 
                // Ask for permission the first time
                if ( insight.optOut === undefined ) {
-                       insight.askPermission( null, function( error, result ) {
+                       insight.askPermission( null, function( _error, result ) {
                                exec( result );
                        } );
                } else {

diff --git a/dist/.eslintrc.json b/dist/.eslintrc.json
index c2aa05c5e021422e7f9543eaac1f4c97e2f41020..45ba0c520461ed26ec96c89a19667b44eef1fcce 100644 (file)
--- a/dist/.eslintrc.json
+++ b/dist/.eslintrc.json
@@ -7,9 +7,10 @@
                // That is okay for the built version
                "no-multiple-empty-lines": "off",
 
-               // Because sizzle is not compatible to jquery code style
+               // Sizzle is not compatible with jQuery code style
                "no-nested-ternary": "off",
                "no-unused-expressions": "off",
+               "no-unused-vars": "off",
                "lines-around-comment": "off",
                "space-in-parens": "off",
                "camelcase": "off",

diff --git a/package.json b/package.json
index 955538e2dc4a3b21fb0ded91b8d685d2fdfcfdea..9e1dcfafc433a37a70ed0ee16e36858cc5d5e5ae 100644 (file)
--- a/package.json
+++ b/package.json
@@ -29,7 +29,7 @@
     "@babel/plugin-transform-for-of": "7.2.0",
     "commitplease": "3.2.0",
     "core-js": "2.6.5",
-    "eslint-config-jquery": "1.0.1",
+    "eslint-config-jquery": "2.0.0",
     "grunt": "1.0.3",
     "grunt-babel": "8.0.0",
     "grunt-cli": "1.3.2",

diff --git a/src/ajax.js b/src/ajax.js
index 4cbefabaaf313df73f6314d2dfdbd3c4cf947ebf..b1f1608401b7c7ce73e14ebe998b0cf4f4b9c750 100644 (file)
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -833,7 +833,7 @@ jQuery.extend( {
        }
 } );
 
-jQuery.each( [ "get", "post" ], function( i, method ) {
+jQuery.each( [ "get", "post" ], function( _i, method ) {
        jQuery[ method ] = function( url, data, callback, type ) {
 
                // Shift arguments if data argument was omitted

diff --git a/src/attributes/attr.js b/src/attributes/attr.js
index 6b5cbd2c4e7c7d1cc8c6f4692c5f35494857a7b1..4c43eb1fc571bacf0aa5a1bdf7dc7514be82ef41 100644 (file)
--- a/src/attributes/attr.js
+++ b/src/attributes/attr.js
@@ -117,7 +117,7 @@ boolHook = {
        }
 };
 
-jQuery.each( jQuery.expr.match.bool.source.match( /\w+/g ), function( i, name ) {
+jQuery.each( jQuery.expr.match.bool.source.match( /\w+/g ), function( _i, name ) {
        var getter = attrHandle[ name ] || jQuery.find.attr;
 
        attrHandle[ name ] = function( elem, name, isXML ) {

diff --git a/src/core.js b/src/core.js
index 19cacf7cd9c42cd83fc716a469f07bc5a9b0eeb5..f57075ce782394c4356f8c4ed6261a91c209afde 100644 (file)
--- a/src/core.js
+++ b/src/core.js
@@ -374,7 +374,7 @@ if ( typeof Symbol === "function" ) {
 
 // Populate the class2type map
 jQuery.each( "Boolean Number String Function Array Date RegExp Object Error Symbol".split( " " ),
-function( i, name ) {
+function( _i, name ) {
        class2type[ "[object " + name + "]" ] = name.toLowerCase();
 } );
 

diff --git a/src/core/access.js b/src/core/access.js
index 842c4a42b3fdda33b45d6139708e7e55babfba2b..54bcc7447145c1fc89607d9583ebffa64abec5d0 100644 (file)
--- a/src/core/access.js
+++ b/src/core/access.js
@@ -38,7 +38,7 @@ var access = function( elems, fn, key, value, chainable, emptyGet, raw ) {
                        // ...except when executing function values
                        } else {
                                bulk = fn;
-                               fn = function( elem, key, value ) {
+                               fn = function( elem, _key, value ) {
                                        return bulk.call( jQuery( elem ), value );
                                };
                        }

diff --git a/src/core/camelCase.js b/src/core/camelCase.js
index 799fb3752f74e13ccab5522e57ca7e2a04f41298..b271044d5ea94ad025eb88461946db161cbd7857 100644 (file)
--- a/src/core/camelCase.js
+++ b/src/core/camelCase.js
@@ -7,7 +7,7 @@ var rmsPrefix = /^-ms-/,
        rdashAlpha = /-([a-z])/g;
 
 // Used by camelCase as callback to replace()
-function fcamelCase( all, letter ) {
+function fcamelCase( _all, letter ) {
        return letter.toUpperCase();
 }
 

diff --git a/src/css.js b/src/css.js
index ac4c66e87acf74ac164567aae75f617d2f94d4e1..d4c34dbb79b7de6ce59fbdacef9dc783c110b85e 100644 (file)
--- a/src/css.js
+++ b/src/css.js
@@ -34,7 +34,7 @@ var
                fontWeight: "400"
        };
 
-function setPositiveNumber( elem, value, subtract ) {
+function setPositiveNumber( _elem, value, subtract ) {
 
        // Any relative (+/-) values have already been
        // normalized at this point
@@ -344,7 +344,7 @@ jQuery.extend( {
        }
 } );
 
-jQuery.each( [ "height", "width" ], function( i, dimension ) {
+jQuery.each( [ "height", "width" ], function( _i, dimension ) {
        jQuery.cssHooks[ dimension ] = {
                get: function( elem, computed, extra ) {
                        if ( computed ) {

diff --git a/src/css/var/swap.js b/src/css/var/swap.js
index 1a9556bad817bf2dc1de3bf4761845b7b572a271..69388e5f7fbddd4c890586b05b62982cd13ade8e 100644 (file)
--- a/src/css/var/swap.js
+++ b/src/css/var/swap.js
@@ -3,7 +3,7 @@ define( function() {
 "use strict";
 
 // A method for quickly swapping in/out CSS properties to get correct calculations.
-return function( elem, options, callback, args ) {
+return function( elem, options, callback ) {
        var ret, name,
                old = {};
 
@@ -13,7 +13,7 @@ return function( elem, options, callback, args ) {
                elem.style[ name ] = options[ name ];
        }
 
-       ret = callback.apply( elem, args || [] );
+       ret = callback.call( elem );
 
        // Revert the old values
        for ( name in options ) {

diff --git a/src/deferred.js b/src/deferred.js
index 0425d3631ff01ed2fbd1c682a652118e19e46bb9..c05a37a23606f4efbb58c559f71a7c4f10da0e04 100644 (file)
--- a/src/deferred.js
+++ b/src/deferred.js
@@ -79,7 +79,7 @@ jQuery.extend( {
                                        var fns = arguments;
 
                                        return jQuery.Deferred( function( newDefer ) {
-                                               jQuery.each( tuples, function( i, tuple ) {
+                                               jQuery.each( tuples, function( _i, tuple ) {
 
                                                        // Map tuples (progress, done, fail) to arguments (done, fail, progress)
                                                        var fn = isFunction( fns[ tuple[ 4 ] ] ) && fns[ tuple[ 4 ] ];

diff --git a/src/effects.js b/src/effects.js
index 4ace4cafaf5a2b78080c9ccb771347adf0c6b8de..76b7cc765828d79e0fb36c4d7ea5308465b11ba1 100644 (file)
--- a/src/effects.js
+++ b/src/effects.js
@@ -7,7 +7,6 @@ define( [
        "./var/rnothtmlwhite",
        "./css/var/cssExpand",
        "./css/var/isHiddenWithinTree",
-       "./css/var/swap",
        "./css/adjustCSS",
        "./data/var/dataPriv",
        "./css/showHide",
@@ -20,7 +19,7 @@ define( [
        "./css",
        "./effects/Tween"
 ], function( jQuery, camelCase, document, isFunction, rcssNum, rnothtmlwhite, cssExpand,
-       isHiddenWithinTree, swap, adjustCSS, dataPriv, showHide ) {
+       isHiddenWithinTree, adjustCSS, dataPriv, showHide ) {
 
 "use strict";
 
@@ -625,7 +624,7 @@ jQuery.fn.extend( {
        }
 } );
 
-jQuery.each( [ "toggle", "show", "hide" ], function( i, name ) {
+jQuery.each( [ "toggle", "show", "hide" ], function( _i, name ) {
        var cssFn = jQuery.fn[ name ];
        jQuery.fn[ name ] = function( speed, easing, callback ) {
                return speed == null || typeof speed === "boolean" ?

diff --git a/src/event/ajax.js b/src/event/ajax.js
index 500b36cdd314b34b8e214a25fe83cc80ec7b0669..dd9c0ffe2c077948a5779bf2ba70180dc33de3fd 100644 (file)
--- a/src/event/ajax.js
+++ b/src/event/ajax.js
@@ -13,7 +13,7 @@ jQuery.each( [
        "ajaxError",
        "ajaxSuccess",
        "ajaxSend"
-], function( i, type ) {
+], function( _i, type ) {
        jQuery.fn[ type ] = function( fn ) {
                return this.on( type, fn );
        };

diff --git a/src/event/alias.js b/src/event/alias.js
index 863c94ad2e85e62b52f80fff665cb8a39743e5c1..46bd1ae80c12107844d98ae2fb29bf8d46bf8573 100644 (file)
--- a/src/event/alias.js
+++ b/src/event/alias.js
@@ -10,7 +10,7 @@ define( [
 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 ) {
+       function( _i, name ) {
 
        // Handle event binding
        jQuery.fn[ name ] = function( data, fn ) {

diff --git a/src/offset.js b/src/offset.js
index 83b1c3a533ef1d4582bf8e6d931e0fd87b6017e2..6e973587062b47e09a5e5bcc58bf2e1988bad5a3 100644 (file)
--- a/src/offset.js
+++ b/src/offset.js
@@ -1,7 +1,6 @@
 define( [
        "./core",
        "./core/access",
-       "./var/document",
        "./var/documentElement",
        "./var/isFunction",
        "./css/var/rnumnonpx",
@@ -12,8 +11,8 @@ define( [
        "./core/init",
        "./css",
        "./selector" // contains
-], function( jQuery, access, document, documentElement, isFunction, rnumnonpx,
-             curCSS, addGetHookIf, support, isWindow ) {
+], function( jQuery, access, documentElement, isFunction, rnumnonpx,
+       curCSS, addGetHookIf, support, isWindow ) {
 
 "use strict";
 
@@ -214,7 +213,7 @@ jQuery.each( { scrollLeft: "pageXOffset", scrollTop: "pageYOffset" }, function(
 // Blink bug: https://bugs.chromium.org/p/chromium/issues/detail?id=589347
 // getComputedStyle returns percent when specified for top/left/bottom/right;
 // rather than make the css module depend on the offset module, just check for it here
-jQuery.each( [ "top", "left" ], function( i, prop ) {
+jQuery.each( [ "top", "left" ], function( _i, prop ) {
        jQuery.cssHooks[ prop ] = addGetHookIf( support.pixelPosition,
                function( elem, computed ) {
                        if ( computed ) {

diff --git a/src/serialize.js b/src/serialize.js
index d8a9a36a4f243954939e3a3766ab7c2d6eb89a79..cd4e99f9f4ae5732534c1c53922825eacaa2e5a8 100644 (file)
--- a/src/serialize.js
+++ b/src/serialize.js
@@ -114,7 +114,7 @@ jQuery.fn.extend( {
                                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 ) {

diff --git a/src/traversing.js b/src/traversing.js
index afbecc4f4dd8204643ebcfe160cb127d5ea89320..de377188f5b92e9eed795237f230d915b56af674 100644 (file)
--- a/src/traversing.js
+++ b/src/traversing.js
@@ -118,7 +118,7 @@ jQuery.each( {
        parents: function( elem ) {
                return dir( elem, "parentNode" );
        },
-       parentsUntil: function( elem, i, until ) {
+       parentsUntil: function( elem, _i, until ) {
                return dir( elem, "parentNode", until );
        },
        next: function( elem ) {
@@ -133,10 +133,10 @@ jQuery.each( {
        prevAll: function( elem ) {
                return dir( elem, "previousSibling" );
        },
-       nextUntil: function( elem, i, until ) {
+       nextUntil: function( elem, _i, until ) {
                return dir( elem, "nextSibling", until );
        },
-       prevUntil: function( elem, i, until ) {
+       prevUntil: function( elem, _i, until ) {
                return dir( elem, "previousSibling", until );
        },
        siblings: function( elem ) {