Vale is an excellent open source grammar and style linter widely used by technical writers and software developers. This instruction describes how to install and configure Vale to work in Visual Studio Code.
The steps below focus on MacOS and assume you have admin right to install software on your MacOS.
On your terminal, type brew install vale.
To confirm Vale is properly installed, type vale -v to check the Vale version. As of March 9, 2023, the latest version is 2.24.0.
Launch Visual Studio Code, click the Extensions icon on the vertical bar and type Vale in the Search box. Install the Vale extension.
Before configuring the Vale extension, you need to get some Vale styles. For explanations about Vale styles, see the official Vale docs. On your terminal, run the following command to get some example Vale styles:
git clone https://github.com/errata-ai/vale-boilerplate.git
In your Visual Studio Code, click the Manage button at the bottom left corner and then choose Settings. Locate Vale setting and configure the Vale CLI to point to the absolute path of the Vale config file .vale.ini you get in step 4. For example, I cloned the repo in step 4 to /Users/taoli/ so I configured mine as /Users/taoli/vale-boilerplate/.vale.ini. You can customize this .vale.ini file to specify where the style rules are, which file types you want Vale to lint. Vale supports Markdown, HTML, TXT, and AsciiDoc files. For details about this .vale.ini file, see the official Vale configuration topic.
Exit Visual Studio Code and start it again. Open a Markdown file and you should see the Vale linter working with wiggle lines flagging the sentences.