Editing FlymakeJavaScript

There are multiple options for checking Javascript syntax that can be used within flymake. The javascript engines %%SpiderMonkey%% and Rhino can both check Javascript syntax. Alternatively, you can use Douglas Crockford's rather handy [http://www.jslint.com JSLint], which is much less forgiving of bad syntax, and can enforce a sensible coding style. Another option is [http://jshint.com/ JSHint], which is a fork of JSLint, modified to be not as strict and more configurable in its requirements than the original. The following describe some of these options. == With Flycheck == See: [[Flycheck]] (a modern alternative to flymake) == With JSLint on Node.js == === Important === As of September 2013, the jslint package available via npm (see below) is based on a seven months old JSLint, which is outdated. This may have changed by now. Be sure to double check. === Steps === 1. Install [[http://nodejs.org/ Node.js]]. 2. From the command line of your OS, install JSLint with <em>npm,</em> the package manager for Node.js: $ npm -g install jslint : On Windows there is [http://stackoverflow.com/questions/18748164/process-exit0-output-disappears an issue] with executing Node.js apps from EMACS 23. Thus, create a wrapper <code>~/.emacs.d/jslint.bat</code> <em>("jslint" needs to be part of the file name!):</em> @ECHO OFF node "%APPDATA%"\npm\node_modules\jslint\bin\jslint.js >"%TEMP%"\jslint.out 2>&1 %* TYPE "%TEMP%"\jslint.out 3. Test JSLint <em>(on Windows use <code>~/.emacs.d/jslint.bat</code>):</em> $ jslint No files specified. [...] : Testing from Emacs' built in shell EShell is recommended: CategoryEshell 4. Install [https://github.com/purcell/flymake-jslint flymake-jslint] and its dependency [https://github.com/purcell/flymake-easy flymake-easy]. 5. Add to <code>~/.emacs</code>: (require 'flymake-jslint) (add-hook 'js-mode-hook 'flymake-jslint-load) 6. Customize flymake-jslint options. On Windows set <code>flymake-jslint-command</code> to: <code>~/.emacs.d/jslint.bat</code> 7. Restart Emacs to make sure that everything loads fine. 8. Test by opening a flawed JavaScript file. [[image:JslintOnWindowsScreenshot]] === Troubleshooting === * Customize <code>flymake-log-level</code> and inspect the <code>*Messages*</code> buffer. * Make sure that the command configured in <code>flymake-jslint-command</code> runs in EShell. * Check <code>flymake-jslint-args</code>. == With JSHint on Node.js == === Variant 1 === I had trouble getting jshint-mode working properly, so I created a simple way to use JSHint from the command-line: [https://github.com/jegbjerg/flymake-node-jshint flymake-node-jshint]. -- Henrik Jegbjerg Hansen <hjh@freecode.dk> I tried Variant 2 first, and I spent several hours trying to make it work (debugging the flymake-jshint.el, jshint-mode.js and jshint.js). I tried Variant 1 and it worked at once! -- Alejandro Russo <mylastname@chalmers.se> === Variant 2 === You can do <pre> $ npm -g install jshint </pre> and then install flymake-jshint using marmalade (http://marmalade-repo.org/). You may need to do the following in /usr/local/bin: <pre> ln -s /usr/local/Cellar/node/0.6.6/lib/node_modules/csslint/cli.js </pre> and then put (add-to-list 'exec-path "/usr/local/bin") somwhere in your .emacs. -Dave Dreisigmeyer == With JSLint on Rhino == First, you will need to install Rhino, and download jslint.js for Rhino [https://developer.mozilla.org/en-US/docs/Rhino]. I've got it located in <tt>~/soft/jslint</tt>, and you will want to update the code below to match where you've put it. Next you will want to create a file called flymake-jslint.el on your LoadPath like the following <pre> (require 'flymake) (defun flymake-jslint-init () (let* ((temp-file (flymake-init-create-temp-buffer-copy 'flymake-create-temp-inplace)) (local-file (file-relative-name temp-file (file-name-directory buffer-file-name)))) (list "rhino" (list (expand-file-name "~/soft/jslint/jslint.js") local-file)))) (setq flymake-allowed-file-name-masks (cons '(".+\\.js$" flymake-jslint-init flymake-simple-cleanup flymake-get-real-file-name) flymake-allowed-file-name-masks)) (setq flymake-err-line-patterns (cons '("^Lint at line \\([[:digit:]]+\\) character \\([[:digit:]]+\\): \\(.+\\)$" nil 1 2 3) flymake-err-line-patterns)) (provide 'flymake-jslint) </pre> and import it from your DotEmacs like so: <pre> (require 'flymake-jslint) (add-hook 'js-mode-hook (lambda () (flymake-mode t))) </pre> You can control options of JSLint by using special comments in your source code which are described in the documentation [http://www.jslint.com/lint.html]. For example, the following is the same as using the recommended options on jslint.com, and also the assume a browser option. It also defines the name !MochiKit, which is imported elsewhere. <pre> /*jslint browser: true, undef: true, eqeqeq: true, nomen: true, white: true */ /*global MochiKit */ </pre> [new] Seems like you really want <code>(flymake-mode 1)</code> in that hook, not <code>(flymake-mode t)</code>. According to the documentation, to turn on the minor mode explicitly requires that the arg be *positive*, not non-nil. --DinoChiesa == With JSLint server on Node.js (lintnode) == If you run the above in a persistent server on v8 instead of invoking rhino every time, it goes about twice as fast. Server code with instructions is available at http://github.com/keturn/lintnode == With SpiderMonkey == JavaScript syntax checking using spidermonkey. This also detects object trailing comma like: <pre> var obj = { a: 1, b: 2, }; // this line is highlighted. </pre> You'll need Karl's [[JavaScriptMode]], spidermonkey 1.5 or greater and emacs 22. <pre> (defconst flymake-allowed-js-file-name-masks '(("\\.json$" flymake-js-init) ("\\.js$" flymake-js-init))) (defcustom flymake-js-detect-trailing-comma t nil :type 'boolean) (defvar flymake-js-err-line-patterns '(("^\\(.+\\)\:\\([0-9]+\\)\: \\(SyntaxError\:.+\\)\:$" 1 2 nil 3))) (when flymake-js-detect-trailing-comma (setq flymake-js-err-line-patterns (append flymake-js-err-line-patterns '(("^\\(.+\\)\:\\([0-9]+\\)\: \\(strict warning: trailing comma.+\\)\:$" 1 2 nil 3))))) (defun flymake-js-init () (let* ((temp-file (flymake-init-create-temp-buffer-copy 'flymake-create-temp-inplace)) (local-file (file-relative-name temp-file (file-name-directory buffer-file-name)))) (list "js" (list "-s" local-file)))) (defun flymake-js-load () (interactive) (defadvice flymake-post-syntax-check (before flymake-force-check-was-interrupted) (setq flymake-check-was-interrupted t)) (ad-activate 'flymake-post-syntax-check) (setq flymake-allowed-file-name-masks (append flymake-allowed-file-name-masks flymake-allowed-js-file-name-masks)) (setq flymake-err-line-patterns flymake-js-err-line-patterns) (flymake-mode t)) (add-hook 'javascript-mode-hook '(lambda () (flymake-js-load))) </pre> == With Rhino == There's another implementation of [http://code.google.com/p/flymake-js/ Flymake JavaScript mode] that sits on top of the Rhino engine. [new] I have some problems with this one. I assume it is a problem with the path to rhino.js and env.js, but I am not sure. I have placed those file in the folder %%c:/emacs/rhino-related/%% which I mention in rhino.js (see below, is this correct?): <pre> // Where you store your files var project_folder = 'c:/emacs/rhino-related/'; // Browser environment wrapper over Rhino load(project_folder + 'env.js'); // For DOM constructing window.location = project_folder + 'blank.html'; var my_script = arguments[0]; // If DOM ready window.onload = function(){ // Avoid recursive inclusion if ("rhino_flymake.js" != my_script) { load(my_script); } } </pre> I get strange errors, like: parsed 'Exception in thread "Thread-0" org.mozilla.javascript.WrappedException: Wrapped java.net.MalformedURLException: unknown protocol: c', no line-err-info It looks like Rhino can not take care of the c: in the path. Anyone who understands what is happening? -- LennartBorgman [new] I do not have a Windows box to verify the fix below, but according to some forum posts, you should declare the path in scheme <code>file:///C:/path/to/file</code>. <pre> var project_folder = 'file:///c:/emacs/rhino-related/'; </pre> -- Nyuhuhuu [new] Thanks Nyuhuhuu, that made it work on Windows. [new] Before I fixed the issue you speak of, I had to fix an apparent problem with 'compilation-error-regexp-alist-alist' in 'flymake.el'. For details on that, please see [http://groups.google.com/group/gnu.emacs.help/browse_thread/thread/0cd12cf6b61e7923#d734eb7aedf67971 this post] on gnu.emacs.help. After that was fixed, I was able to get the Java Rhino process running on target with this (using the Windows build of Emacs, on Windows XP): <pre> var project_folder = 'c:\\Progra~1\\emacs\site\\rhino-web-browser-js-environment\\'; </pre> Then in my 'flymake-js-init' function definition, I have this: <pre> (list "java" (list "-jar" "c:/Progra~1/rhino1_6R7/js.jar" "c:/Progra~1/emacs/site/rhino-web-browser-js-environment/rhino_flymake.js" local-file)))) </pre> That said, after said success I ran into other problems, apparently unrelated to any of my previous fixes and configurations, down the road. Please see the last half of the third comment on [http://groups.google.com/group/gnu.emacs.help/browse_thread/thread/0cd12cf6b61e7923#d734eb7aedf67971 this post] on gnu.emacs.help. It would be very cool if this could be made to work. If we can figure it out, we could make a nice how-to on this that I bet a lot of people would benefit from. -- ChristopherMBalz [new] I get a lot of errors on the first line, like - Context.Java(1757) - MemberBox.java(187) etc. That is this? == With JSHINT on Windows using Cscript.exe == There's no need to install Rhino on Windows; Windows has a built-in Javascript engine in WSH. Therefore you can run a JS program on any Windows, via WSH. Which means you can run <em>JSHINT</em>. Please note that this solution does not work for <em>JSLint</em>: Since February 2013, [http://tech.groups.yahoo.com/group/jslint_com/message/3128 JSLint requires ECMAScript Fifth Edition], and does not run with WSH anymore. There are two modules; both allow you to use JSHINT as the flymake tool for .js buffers on windows. The first, [http://code.google.com/p/jslint-for-wsh/source/browse/#svn/trunk flymake-for-jslint-for-wsh.el], requires you to download JSHINT, modify it slightly, save it, and set a variable in your .emacs pointing to the modified script. [http://cheeso.members.winisp.net/srcview.aspx?dir=emacs&file=fly-jshint-wsh.el A newer version] downloads and modifies JSHINT at runtime. This version is also available on the Marmalade Repo as [http://marmalade-repo.org/packages/fly-jshint-wsh fly-jshint-wsh]. A sample of using jslint-for-wsh.js as a "compile" command in emacs: http://i49.tinypic.com/11kuypx.jpg == See Also == NodeJs ---- FlyMake CategoryJavaScript

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