ESLint 2.9.0 fixes some minor bugs that we have been experiencing and
introduces some new rules that we may wish to consider.
PR-URL: https://github.com/nodejs/node/pull/6498
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
ESLint is a tool for identifying and reporting on patterns found in ECMAScript/JavaScript code. In many ways, it is similar to JSLint and JSHint with a few exceptions:
ESLint is a tool for identifying and reporting on patterns found in ECMAScript/JavaScript code. In many ways, it is similar to JSLint and JSHint with a few exceptions:
@ -32,6 +40,8 @@ After that, you can run ESLint on any JavaScript file:
eslint test.js test2.js
eslint test.js test2.js
**Note:** `eslint --init` is intended for setting up and configuring ESLint on a per-project basis and will perform a local installation of ESLint and its plugins in the directory in which it is run. If you prefer using a global installation of ESLint, any plugins used in your configuration must also be installed globally.
## Configuration
## Configuration
After running `eslint --init`, you'll have a `.eslintrc` file in your directory. In it, you'll see some rules configured like this:
After running `eslint --init`, you'll have a `.eslintrc` file in your directory. In it, you'll see some rules configured like this:
@ -67,13 +77,19 @@ These folks keep the project moving and are resources for help:
@ -98,15 +114,19 @@ I do like JSHint. And I like Anton and Rick. Neither of those were deciding fact
That's not really a question, but I got it. I'm not trying to convince you that ESLint is better than JSHint. The only thing I know is that ESLint is better than JSHint for what I'm doing. In the off chance you're doing something similar, it might be better for you. Otherwise, keep using JSHint, I'm certainly not going to tell you to stop using it.
That's not really a question, but I got it. I'm not trying to convince you that ESLint is better than JSHint. The only thing I know is that ESLint is better than JSHint for what I'm doing. In the off chance you're doing something similar, it might be better for you. Otherwise, keep using JSHint, I'm certainly not going to tell you to stop using it.
### How does ESLint performance compare to JSHint and JSCS?
### How does ESLint performance compare to JSHint?
ESLint is slower than JSHint, usually 2-3x slower on a single file. This is because ESLint uses Espree to construct an AST before it can evaluate your code whereas JSHint evaluates your code as it's being parsed. The speed is also based on the number of rules you enable; the more rules you enable, the slower the process.
ESLint is slower than JSHint, usually 2-3x slower on a single file. This is because ESLint uses Espree to construct an AST before it can evaluate your code whereas JSHint evaluates your code as it's being parsed. The speed is also based on the number of rules you enable; the more rules you enable, the slower the process.
Despite being slower, we believe that ESLint is fast enough to replace JSHint without causing significant pain.
Despite being slower, we believe that ESLint is fast enough to replace JSHint without causing significant pain.
ESLint is faster than JSCS, as ESLint uses a single-pass traversal for analysis whereas JSCS using a querying model.
### I heard ESLint is going to replace JSCS?
Yes. Since we are solving the same problems, ESLint and JSCS teams have decided to join forces and work together in the development of ESLint instead of competing with each other. You can read more about this in both [ESLint](http://eslint.org/blog/2016/04/welcoming-jscs-to-eslint) and [JSCS](https://medium.com/@markelog/jscs-end-of-the-line-bc9bf0b3fdb2#.u76sx334n) announcements.
### So, should I stop using JSCS and start using ESLint?
If you are using both JSHint and JSCS on your files, then using just ESLint will be faster.
Not yet. We are still working to smooth the transition. You can see our progress [here](https://github.com/eslint/eslint/milestones/JSCS%20Compatibility). We’ll announce when all of the changes necessary to support JSCS users in ESLint are complete and will start encouraging JSCS users to switch to ESLint at that time. Meanwhile, we recommend you to upgrade to JSCS 3.0 and provide feedback to the team.
### Is ESLint just linting or does it also check style?
### Is ESLint just linting or does it also check style?
Rich Trott
9 years ago
Evan Lucas