Eslint Visual Studio Code

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Enable linters #. To enable linters other than the default PyLint, open the Command Palette ( Ctrl+Shift+P) and select the Python: Select Linter command. This command adds 'python.linting.Enabled': true to your settings, where is the name of the chosen linter. See Specific linters for details.

A mountain of crumbs pdf free download. DeepScan provides a Visual Studio Code extension enabling on-the-fly analysis for JavaScript and TypeScript in development.

Overview

  • In this short video I will show you how to setup ESLint and JSCS in Visual Studio Code.While visual studio code is configured out of the box with basic ESLin.
  • Visual Studio Code does not show red underline for eslint errors, although the extension still works #1187. Closed rudyhuynh opened this issue Feb 22, 2021 2 comments Closed Visual Studio Code does not show red underline for eslint errors, although the extension still works #1187. Rudyhuynh opened this issue Feb 22, 2021 2 comments Labels.

DeepScan's extension for Visual Studio Code helps you to see bugs and quality issues on the fly in your Visual Studio Code.

  • Report issues in Problems panel when you open or save a JavaScript/TypeScript file and save it. Supported extensions are *.js, *.jsx, *.mjs, *.ts, *.tsx, and *.vue.
  • Highlight issues in the code.
  • Show a rule description using a code action. When you click the light bulb of the issue, you can see the detailed description of the rule and grasp what's the problem.

You can browse it in the Visual Studio Code Marketplace and install from within Visual Studio Code.

It's free and open source.

Considerations

Yes, it's free but note that:

Free version transfers the code to the DeepScan server for inspection when you save your changes.

Although your code is completely deleted from the server right after the inspection, you should confirm that your code is transferred to the DeepScan server.

You can confirm it by pressing the Confirm button that appears when restarting VS Code after the installation.

If you want to analyze without DeepScan server, check here.

Options

You can configure options (enablement, server, ignored rules, ..) through user and workspace settings.

To see all the available options, refer to Settings Options.

Features

Disabling Rules with Inline Comments

While you can exclude project-wide rules via deepscan.ignoreRules option, you can also disable a rule in a file using inline comment.

Visual Studio Code Eslint Not Working

By Ignore this line and Ignore this rule code actions, you can add an inline comment easier.

For detailed information, refer to Disabling rules.

Viewing Rule Information

For a detected issue, you can view the corresponding rule information such as severity, description, non-compliant and compliant examples.

When you click Show rule <rule name> code action menu in the line where the issue is detected, you can view the detailed information of the rule on the right side.

Embedded Mode

Our Visual Studio Code extension has the limitation for transferring the file to the DeepScan server and analyzing a file one by one.

DeepScan supports an embedded mode, which works standalone without the DeepScan server. It works with the local language server so you can:

  • never worry about transferring the code outside.
  • analyze a whole project rather than a file.

System Requirements

Java

To run the DeepScan server, Java is required.

  • Oracle JRE 8 and above
  • OpenJDK 8 and above

The path to a Java executable must be set in PATH environment variable. Otherwise, you will not be able to run the DeepScan server. (resulting an error such as Cannot start the DeepScan server.)

DeepScan Extension

Also, the DeepScan extension 1.7.0 or above is required for the embedded mode. (The latest is recommended, so either set up to auto-update or check whether there is the latest update before setting up this.)

Installation

To run as the embedded mode, the following settings are required:

  • Server Embedded: Enable: Controls whether DeepScan inspection should be executed via the embedded server rather than DeepScan server. (Restart required)
  • Server Embedded: License: Configures the license for the embedded analysis.
  • Server Embedded: Server Jar: Configures the JAR file for the embedded server. (Restart required)

To install, complete the above settings and restart VS Code.

To upgrade, change deepscan.serverEmbedded.serverJar to the path of a newer JAR file and restart VS Code.

Analysis Target

For detailed information about the analysis target, refer to the following:

Inspect Project

You can analyze a whole project by clicking DeepScan: Inspect Project in the command palette. The entire project is analyzed and the detected issues are displayed in Problems view.

You can specify patterns of files to exclude by deepscan.ignorePatterns option (gitignore format). An example to exclude App.vue file and lib directory is:

ESLint Analysis

Run ESLint. You can see the ESLint alarms altogether with DeepScan's issues.

Node.js and eslint package are required in the local or global. Note that NODE_PATH environment variable is necessary to load the eslint module installed in global.

It directly uses the package so your custom configurations and plugins are applied as is.

The options are as follows:

  • Server Embedded > Eslint: Enable: Controls whether ESLint analysis should be executed.
  • Server Embedded > Eslint: Merge: Option for how identical issues of DeepScan and ESLint are merged. Default is deepscan.
    • deepscan: Show only DeepScan issue (e.g., BAD_TYPEOF_COMPARISON). Default.
    • eslint: Show only ESLint issue (e.g., valid-type-of)
    • both: Show all issues as is (e.g., BAD_TYPEOF_COMPARISON and valid-type-of)

How to set up Eslint with Typescript in VS Code

Published on 11/16/2019

Run Eslint Vscode

eslint

If you have ever been part of a development team, you probably know that every single one of us has a different code formatting, semantics standards (and that's totally fine 😅). However, when you are all developing on one thing, it's very handy to follow one strict pattern so the codebase isn't a mixture of everything.

However, it would be pretty hard and inefficient for all developers to get used to one pattern (because we have side-projects where we use different style-guide and so on).

Eslint to the rescue!

Eslint is a tool, which forces the developer to format their code according to selected rules.

E.g. rule: don't use semicolons in your code.

So this way, all developers would have errors in their IDE/Text editor if they had semicolons in their code, but for some reason, they might ignore that errors/warnings and still commit changes. Fortunately, eslint can handle even that and automatically fix the errors on file save!

Unfortunately, developers might not have prepared their IDE/Text editor to work with eslint and wouldn't see those errors, but we can still create an eslint script which will run on our CI. That way we can ensure only correctly formatted code will be merged. 🙌

Why typescript?

You probably heard of typescript, it's basically javascript with types (but there is much more in it!). It adds another layer of certainty to your code. However, it is a little bit tricky to make it work with eslint so let's dive into it!

Visual Studio Code setup

First of all, we need to 'teach' our editor to understand eslint 😄So we'll install this extension.

After installation, we need to explicitly tell eslint extension to watch typescript files for linting errors (by default it lints only javascript and JSX files). Follow these instructions:

  • Inside VS Code use: Ctrl+Shift+P or Shift+Cmd+P
  • Type: Preferences: Open Settings (JSON)
  • Select the option
  • Paste this code inside the opened JSON file
Code

Note that if you hit Ctrl+Shift+P or Shift+Cmd+P in VS Code and type eslint it will show you all commands available for this extensions! However, the commands won't work because we haven't installed eslint dependency, let's do it now!

Install eslint to your project or globally on your machine

We have two options now:

  1. We will install eslint dependency globally (means it will be available for all projects on your machine, cool!)
  1. We will install dependencies per-project, which can be useful to explicitly tell a developer to use these.

It's your choice which one of these you want to use

Teach Eslint to work with Typescript

Eslint by default doesn't understand Typescript syntax. That's why you might hear of tslint, which is (was) used instead of eslint for Typescript project, but the backers of this package announced earlier this year deprecation of tslint in favour of typescript-eslint project (which is monorepo, so we are gonna install few packages from it).

We'll make configuration file for eslint. It can be of three different types:

  • Javascript file
  • JSON file - we'll take this one
  • YAML file
  • eslintConfig field in package.json

Create .eslintrc file in the root of your project and paste this code inside:

We are adding the @typescript-eslint/parser (which will parse typescript files, so eslint understands them correctly). Then under plugins, we add @typescript-eslint plugin which gives us the possibility to add rules specific to typescript code. Under rules we added some sample rules (no semicolons allowed, and use single quotes instead of double)

With this, if you create anywhere file with .ts or .tsx extension and write code like this:

You should see the string being underlined and the semicolon too. Showing you what rules this code violates.

Adding automatic lint errors fixing!

Eslint Visual Studio Code Typescript

Cool, now editor shows error when we type something that violates our eslint rules and we can manually fix them, but that's time-consuming, we can do better with automatic fixing!

All we need to do is to tell our VS Code eslint extension to run eslint --fix command on file save.

  • Inside VS Code use: Ctrl+Shift+P or Shift+Cmd+P
  • Type: Preferences: Open Settings (JSON)
  • Select the option
  • Update eslint-related code inside the opened JSON file

Now whenever you save typescript file with eslint errors, it will be automatically fixed. Awesome!

Executing eslint on command line!

We are almost finished, the last piece of work we need to do is to set up a script that will run eslint check.

The script might be executed on your CI to ensure that pushed code is correctly formatted.

Eslint Autofix Vs Code

To check code on your command line is very easy with eslint, look at this:

However, there is a little gotcha in these commands. Do you know why? 🤔

It scans only javascript files by default, so typescript files will be ignored. So if you didn't have any javascript file in your project and only typescript files, you would see something like this:

So to lint typescript file we need to add an argument --ext <comma-seperated-list-of-file-extensions-to-watch. So with this in mind, the command would look like this:

That's all, you have now configured eslint with typescript! 😎