Configuration file

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

The configuration file supports .json and .jsonc extensions. Since v1.18, Deno will automatically detect deno.json or deno.jsonc configuration file if it's in your current working directory (or parent directories). To manually tell Deno to use a specific configuration file pass --config path/to/file.json flag.

⚠️ Starting with Deno v1.22 you can disable automatic detection of the configuration file, by passing --no-config.

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.

Example

{
  "compilerOptions": {
    "allowJs": true,
    "lib": ["deno.window"],
    "strict": true
  },
  "importMap": "import_map.json",
  "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"
    }
  },
  "test": {
    "files": {
      "include": ["src/"],
      "exclude": ["src/testdata/"]
    }
  }
}

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