Configuration file

Deno supports configuration file that allows to customize built-in TypeScript compiler, formatter and linter.

Deno will automatically detect the configuration file if its in your current working directory (or parent or ancestor of your CWD). To manually tell Deno to use a specific configuration file pass --config path/to/file.json flag.

Note that using a configuration file is not required now, and will not be required in the future. Deno still works best with the default options and no configuration file. All options specified in the configuration file can also be set using command line flags (for example --options-use-tabs for deno fmt). Using the configuration file should be considered an "as needed" feature, not something every user should be reaching to as the first thing when setting up a project.

The configuration file supports .json and .jsonc extensions. We recommend to use deno.json or deno.jsonc as a file name, as an automatic lookup of this file is planned for the upcoming releases.

Example

{
  "compilerOptions": {
    "allowJs": true,
    "lib": ["deno.window"],
    "strict": true
  },
  "lint": {
    "files": {
      "include": ["src/"],
      "exclude": ["src/testdata/"]
    },
    "rules": {
      "tags": ["recommended"],
      "include": ["ban-untagged-todo"],
      "exclude": ["no-unused-vars"]
    }
  },
  "fmt": {
    "files": {
      "include": ["src/"],
      "exclude": ["src/testdata/"]
    },
    "options": {
      "useTabs": true,
      "lineWidth": 80,
      "indentWidth": 4,
      "singleQuote": true,
      "proseWrap": "preserve"
    }
  }
}

JSON schema

A JSON schema file is available for editors to provide autocomplete. The file is versioned and available at: https://deno.land/x/deno/cli/schemas/config-file.v1.json