code.delx.au - gnu-emacs-elpa/blob - packages/js2-mode/NEWS.md

   1 # History of user-visible changes
   2
   3 ## 2016-06-23
   4
   5 * New variable `js2-mode-assume-strict`, for use with ES6 modules.
   6 * Support for JSDoc @callback, @func and @method tags.
   7 * Object properties are highlighted using a different face:
   8   `js2-object-property`, which has no color by default.
   9 * Experimental support for object rest/spread ECMAScript proposal.
  10 * `js2-getter-setter-node` is renamed to `js2-method-node`, together with
  11   its related functions.  It already handles generator methods, and we
  12   added support for async methods (see below), so the old name would get
  13   more confusing.
  14 * Support for default parameters in destructuring.  It should work for both
  15   objects and arrays, in both literals and function arguments.
  16 * New mode: `js2-jsx-mode`, deriving from `js2-mode`.  Supports indentation of
  17   JSXElement expressions wrapped within parentheses or as function arguments.
  18   Indentation is customizable via `sgml-attribute-offset`.
  19 * Experimental support for async/await ECMAScript proposal.
  20
  21 ## 20150909
  22
  23 * `js2-mode` now derives from `js-mode`. That means the former
  24   function will run `js-mode-hook`, as well as `js2-mode-hook`. The
  25   key bindings will default to `js-mode-map` where they're not set in
  26   `js2-mode-map`. And in Emacs 25 or later (including the snapshot
  27   builds), `js2-mode` uses the indentation code from `js-mode`.  Where
  28   feasible, the user options (and functions) now have aliases, but if
  29   you're using Emacs 25 and you see an indentation-related setting
  30   that stopped working, try looking for a corresponding one in the
  31   `js` group: `M-x customize-group RET js RET`.
  32
  33 * New command: `js2-jump-to-definition`. It's bound to `M-.` by
  34   default, via remapping `js-find-symbol`. To get back to the default
  35   `M-.` binding (e.g. `find-tag`), put this in your init file:
  36
  37       (eval-after-load 'js (define-key js-mode-map (kbd "M-.") nil))
  38
  39 ## 20150713
  40
  41 * More comprehensive strict mode warnings and syntax errors.
  42 * New minor mode: `js2-highlight-unused-variables-mode`.
  43 * `js2-pretty-multiline-declarations` can take the value `dynamic` now.
  44
  45 ## 20150202
  46
  47 Support for:
  48
  49 * [ES6 modules](http://www.2ality.com/2014/09/es6-modules-final.html).
  50 * [Short-hand object literals](http://ariya.ofilabs.com/2013/02/es6-and-object-literal-property-value-shorthand.html).
  51 * [Method definitions](http://ariya.ofilabs.com/2013/03/es6-and-method-definitions.html).
  52 * ['u' and 'y' RegExp flags](https://mathiasbynens.be/notes/es6-unicode-regex).
  53 * [Computed property names](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-object-initializer).
  54 * [Class statements and expressions](https://github.com/lukehoban/es6features#classes).
  55 * [Template strings](http://tc39wiki.calculist.org/es6/template-strings/), including tagged ones.
  56
  57 The variable `js2-allow-keywords-as-property-names` has been
  58 removed. Instead we check if `js2-language-version` is 180 or highter.
  59
  60 ## 20141115
  61
  62 Support for:
  63
  64 * Unicode characters in identifiers (improved).
  65 * [Delegating yield](http://wiki.ecmascript.org/doku.php?id=harmony:generators#delegating_yield).
  66 * [ES6 numeric literals](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-literals-numeric-literals) (octal, binary).
  67 * Harmony [array and generator comprehensions](http://wingolog.org/archives/2014/03/07/es6-generator-and-array-comprehensions-in-spidermonkey).
  68
  69 ## 20131106
  70
  71 Support for:
  72
  73 * [Arrow functions](http://wiki.ecmascript.org/doku.php?id=harmony:arrow_function_syntax)
  74 * [Generators](http://wiki.ecmascript.org/doku.php?id=harmony:generators)
  75 * [Spread operator](http://wiki.ecmascript.org/doku.php?id=harmony:spread)
  76
  77 ## 20130510
  78
  79 ### Support for JSLint global declaration
  80
  81 See the docstring for `js2-include-jslint-globals`.
  82
  83 ## 20130216
  84
  85 ### We don't rebind `RET` anymore
  86
  87 Because well-behaving major modes aren't supposed to do that.
  88
  89 So pressing it won't continue a block comment, or turn a string into a concatenation.
  90 Pressing `M-j`, however, will.
  91
  92 The options `js2-indent-on-enter-key` and `js2-enter-indents-newline` were also removed.
  93
  94 To bring back the previous behavior, put this in your init file:
  95
  96 ```js
  97 (eval-after-load 'js2-mode
  98   '(define-key js2-mode-map (kbd "RET") 'js2-line-break))
  99 ```
 100
 101 ## 20120617
 102
 103 ### Support for [default](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/default_parameters) and [rest](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/rest_parameters) parameters
 104
 105 ## 20120614
 106
 107 ### Support for [for..of loops](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of)
 108
 109 ## Older changes
 110
 111 ### Popular indentation style
 112
 113 ```js
 114 [foo, bar, baz].forEach(function (v) {
 115     if (validate(v))
 116         process(v);
 117 });
 118
 119 [a, b, c].some(function (v) {
 120     return validate(v);
 121 });
 122 ```
 123
 124 ### Pretty multiline variable declaration
 125
 126 In the original mode,
 127
 128 ```js
 129 var foo = 10,
 130 bar = 20,
 131 baz = 30;
 132 ```
 133
 134 In this mode when the value of `js2-pretty-multiline-declarations` is non-nil,
 135
 136 ```js
 137 var foo = 10,
 138     bar = 20,
 139     baz = 30;
 140 ```
 141
 142 ### Abbreviated destructuring assignments
 143
 144 ```js
 145 let {a, b}       = {a: 10, b: 20}; // Abbreviated   (Not supported in the original mode)
 146 let {a: a, b: b} = {a: 10, b: 20}; // Same as above (Supported in the original mode)
 147
 148 (function ({responseText}) { /* */ })(xhr); // As the argument of function
 149
 150 for (let [k, { name, age }] in Iterator(obj)) // nested
 151     print(k, name, age);
 152 ```
 153
 154 ### Expression closure in property value
 155
 156 ```js
 157 let worker = {
 158     get age() 20,
 159     get sex() "male",
 160     fire: function () _fire()
 161 };
 162 ```
 163
 164 ### Fix for odd indentation of "else if" with no braces
 165
 166 In the original mode,
 167
 168 ```js
 169 if (foo)
 170     return foo;
 171 else if (bar)
 172 return bar;      // here
 173 ```
 174
 175 In this mode,
 176
 177 ```js
 178 if (foo)
 179     return foo;
 180 else if (bar)
 181     return bar;  // fixed
 182 ```
 183
 184 ### Imenu support for function nesting
 185
 186 Supports function nesting and anonymous wrappers:
 187
 188 ```js
 189 (function() {
 190   var foo = function() {
 191     function bar() { // shown as foo.bar.<definition-1>
 192       function baz() {} // foo.bar.baz
 193       var qux = function() {}; // foo.bar.quux
 194     }
 195   };
 196 });
 197 ```
 198
 199 Examples of output:
 200
 201 * [jQuery 1.5](https://gist.github.com/845449)
 202 * [Underscore.js](https://gist.github.com/824262)
 203 * [Backbone.js](https://gist.github.com/824260)
 204
 205 For library-specific extension methods like `$.extend` and `dojo.declare`, see [js2-imenu-extras](/mooz/js2-mode/blob/master/js2-imenu-extras.el).
 206
 207 ### Undeclared/external variables highlighting
 208
 209 Original mode highlights them only on the left side of assignments:
 210
 211 ```js
 212 var house;
 213 hose = new House(); // highlights "hose"
 214 ```
 215
 216 Here they are highlighted in all expressions:
 217
 218 ```js
 219 function feed(fishes, food) {
 220     for each (var fish in fshes) { // highlights "fshes"
 221         food.feed(fsh); // highlights "fsh"
 222     }
 223     hood.discard(); // highlights "hood"
 224 }
 225 ```
 226
 227 Destructuring assignments and array comprehensions (JS 1.7) are supported:
 228
 229 ```js
 230 let three, [one, two] = [1, 2];
 231 thee = one + two; // highlights "thee"
 232
 233 function revenue(goods) {
 234     // highlights "coast"
 235     return [price - coast for each ({price, cost} in goods)].reduce(add);
 236 }
 237 ```