@fimbul/mithotyn

Mithotyn

TypeScript LanguageService Plugin that provides real-time in-editor linting while you type.

Make sure to also read the full documentation of all available modules.

Installation

npm install --save-dev @fimbul/wotan @fimbul/mithotyn
# or
yarn add -D @fimbul/wotan @fimbul/mithotyn

Usage

To enable this plugin, you need to add @fimbul/mithotyn as plugin in your tsconfig.json. For example:

{
  "compilerOptions": {
    "plugins": [
      { "name": "@fimbul/mithotyn" }
    ],
    // your existing compilerOptions
    "strict": true,
  }
}

Make sure you have @fimbul/wotan installed in the project directory or a parent directory.

Using your existing .fimbullinter.yaml

Like the CLI this plugin uses your configurations from a file named .fimbullinter.yaml. The main difference is that it doesn't only look for this file in the current directory but also in all parent directories. This is necessary because there is likely only one .fimbullinter.yaml in the root of your workspace, but multiple TypeScript projects may exist in subdirectories.

The following options are used if present in that file. Note that all paths and modules are resolved relative to the directory containing this configuration file.

• modules: loads the specified plugin modules to customize linter behavior
• config: use the specified configuration file for all files
• files: only lint files matching one of the given glob patterns
• exclude: exclude files matching one of the given glob patterns

Configuration Options

To customize your in-editor linting experience you can use the following configuration options:

• displayErrorsAsWarnings: boolean: Report findings with severity error as warning to make them distinguishable from real type errors (e.g. green instead of red squiggles in VS Code)

Example:

{
  "compilerOptions": {
    "plugins": [
      {
        "name": "@fimbul/mithotyn",
        "displayErrorsAsWarnings": true
      }
    ],
    // your existing compilerOptions
    "strict": true,
  }
}

Usage in VS Code

In Visual Studio Code you can choose between the version of TypeScript that comes bundled with the editor or the local one installed in the workspace. Due to technical limitations you need to choose the workspace version to correctly pick up the plugin configured in the previous section.

• open command palette while a TypeScript or JavaScript file is opened
• select TypeScript: Select TypeScript Version.
• select Use Workspace Version

Other editors might work the same as VS Code.

To work around this limitation there will be an editor plugin that automatically loads this LanguageService plugin. Stay tuned.

Limitations

There are some limitations of the current implementation.

• doesn't use processors at all

The following limitations will likely be fixed in future releases.

• Currently only works with TypeScript installed in your workspace, see Usage in VS Code
• doesn't provide code fixes for findings
• doesn't validate .wotanrc.yaml and .fimbullinter.yaml files
• doesn't refresh lint findings if configuration changes; you need to reopen or change the file

License

Apache-2.0 © Klaus Meinhardt

Changelog

v0.18.0

:warning: Breaking Changes:

• configuration: patterns (exclude and overrides[].files) match dotfiles, e.g. *.spec.ts now matches .foo.spec.ts.
• disable comments: handling of nested ranges changed. //wotan-enable-line in a line disabled by //wotan-disable-next-line is ignored
• API: completely refactored FileFilterFactory, FileFilter, LineSwitchFilterFactory, LineSwitchParser and DefaultLineSwitchParser

Features:

• unchecked JS files (//@ts-nocheck or checkJs: false) are never linted with type information
• added report-useless-directives CLI option to report unused and redundant enable and disable comments

Bugfixes:

• wotan: added missing exports to the public API
• patterns in configuration files match dotfiles (see breaking changes)