When using the CLI or many third-party tools, a file named tslint.json is used to configure which rules get run.

tslint.json files can have the following fields specified:

  • extends?: string | string[]: A path or array of paths to other configuration files which are extended by this configuration. This value is handled using node module resolution semantics. For example a value of “tslint-config” would cause TSLint to try and load the main file of a module named “tslint-config” as a configuration file. A value of “./tslint-config”, on the other hand, would be treated as a relative path to file.
  • rulesDirectory?: string | string[]: A path or array of paths to a directories of custom rules. This will always be treated as a relative or absolute path.
  • rules?: { [name: string]: RuleSetting }: A map of rule names to their configuration settings.
    • Each rule is associated with an object containing:
      • options?: any: An array of values that are specific to a rule.
      • severity?: "default" | "error" | "warning" | "off": Severity level. Level “error” will cause exit code 2.
    • A boolean value may be specified instead of the above object, and is equivalent to setting no options with default severity. Not all possible rules are listed here, be sure to check out the full list. These rules are applied to .ts and .tsx files.
  • jsRules?: any: Same format as rules. These rules are applied to .js and .jsx files.
  • defaultSeverity?: "error" | "warning" | "off": The severity level used when a rule specifies a default warning level. If undefined, “error” is used. This value is not inherited and is only applied to rules in this file.

tslint.json configuration files may have JavaScript-style // single-line and /* multi-line */ comments in them (even though this is technically invalid JSON). If this confuses your syntax highlighter, you may want to switch it to JavaScript format.

An example tslint.json file might look like this:

    "rulesDirectory": ["path/to/custom/rules/directory/", "another/path/"],
    "rules": {
        "max-line-length": {
            "options": [120],
        "new-parens": true,
        "no-arg": true,
        "no-bitwise": true,
        "no-conditional-assignment": true,
        "no-consecutive-blank-lines": false,
        "no-console": {
            "options": [
    "jsRules": {
        "max-line-length": {
            "options": [120],