[ts] Property 'name' of type 'string' is not assignable to string index type '{ [k: string]: any; }'. [2411]

[CarstenLeue]

Running json2ts on the json schema for package.json (http://json.schemastore.org/package) generates a typescript interface with many errors of the kind:

[ts] Property 'name' of type 'string' is not assignable to string index type '{ [k: string]: any; }'. [2411]

[bcherny]

Thanks for the report! Can you paste the output?

[CarstenLeue]

/* tslint:disable */
/**
 * This file was automatically generated by json-schema-to-typescript.
 * DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,
 * and run json-schema-to-typescript to regenerate this file.
 */

export type JSONSchemaForNPMPackageJsonFiles = CoreProperties &
  JspmDefinition &
  (
    | {
        bundleDependencies?: BundledDependency;
        [k: string]: any;
      }
    | {
        bundledDependencies?: BundledDependency;
        [k: string]: any;
      });
/**
 * A person who has been involved in creating or maintaining this package
 */
export type Person =
  | {
      [k: string]: any;
    }
  | string;
/**
 * Run AFTER the package is published
 */
export type ScriptsPublishAfter = string;
/**
 * Run AFTER the package is installed
 */
export type ScriptsInstallAfter = string;
/**
 * Run BEFORE the package is uninstalled
 */
export type ScriptsUninstallBefore = string;
/**
 * Run BEFORE bump the package version
 */
export type ScriptsVersionBefore = string;
/**
 * Run by the 'npm test' command
 */
export type ScriptsTest = string;
/**
 * Run by the 'npm stop' command
 */
export type ScriptsStop = string;
/**
 * Run by the 'npm start' command
 */
export type ScriptsStart = string;
/**
 * Run by the 'npm restart' command. Note: 'npm restart' will run the stop and start scripts if no restart script is provided.
 */
export type ScriptsRestart = string;
/**
 * Array of package names that will be bundled when publishing the package.
 */
export type BundledDependency = string[];

export interface CoreProperties {
  /**
   * The name of the package.
   */
  name?: string;
  /**
   * Version must be parseable by node-semver, which is bundled with npm as a dependency.
   */
  version?: string;
  /**
   * This helps people discover your package, as it's listed in 'npm search'.
   */
  description?: string;
  /**
   * This helps people discover your package as it's listed in 'npm search'.
   */
  keywords?: string[];
  /**
   * The url to the project homepage.
   */
  homepage?: string;
  /**
   * The url to your project's issue tracker and / or the email address to which issues should be reported. These are helpful for people who encounter issues with your package.
   */
  bugs?:
    | {
        [k: string]: any;
      }
    | string;
  /**
   * You should specify a license for your package so that people know how they are permitted to use it, and any restrictions you're placing on it.
   */
  license?: string;
  /**
   * You should specify a license for your package so that people know how they are permitted to use it, and any restrictions you're placing on it.
   */
  licenses?: {
    type?: string;
    url?: string;
    [k: string]: any;
  }[];
  author?: Person;
  /**
   * A list of people who contributed to this package.
   */
  contributors?: Person[];
  /**
   * A list of people who maintains this package.
   */
  maintainers?: Person[];
  /**
   * The 'files' field is an array of files to include in your project. If you name a folder in the array, then it will also include the files inside that folder.
   */
  files?: string[];
  /**
   * The main field is a module ID that is the primary entry point to your program.
   */
  main?: string;
  bin?:
    | string
    | {
        [k: string]: any;
      };
  /**
   * Specify either a single file or an array of filenames to put in place for the man program to find.
   */
  man?: string[];
  directories?: {
    /**
     * If you specify a 'bin' directory, then all the files in that folder will be used as the 'bin' hash.
     */
    bin?: string;
    /**
     * Put markdown files in here. Eventually, these will be displayed nicely, maybe, someday.
     */
    doc?: string;
    /**
     * Put example scripts in here. Someday, it might be exposed in some clever way.
     */
    example?: string;
    /**
     * Tell people where the bulk of your library is. Nothing special is done with the lib folder in any way, but it's useful meta info.
     */
    lib?: string;
    /**
     * A folder that is full of man pages. Sugar to generate a 'man' array by walking the folder.
     */
    man?: string;
    test?: string;
    [k: string]: any;
  };
  /**
   * Specify the place where your code lives. This is helpful for people who want to contribute.
   */
  repository?:
    | {
        [k: string]: any;
      }
    | string;
  /**
   * The 'scripts' member is an object hash of script commands that are run at various times in the lifecycle of your package. The key is the lifecycle event, and the value is the command to run at that point.
   */
  scripts?: {
    /**
     * Run BEFORE the package is published (Also run on local npm install without any arguments)
     */
    prepublish?: string;
    publish?: ScriptsPublishAfter;
    postpublish?: ScriptsPublishAfter;
    /**
     * Run BEFORE the package is installed
     */
    preinstall?: string;
    install?: ScriptsInstallAfter;
    postinstall?: ScriptsInstallAfter;
    preuninstall?: ScriptsUninstallBefore;
    uninstall?: ScriptsUninstallBefore;
    /**
     * Run AFTER the package is uninstalled
     */
    postuninstall?: string;
    preversion?: ScriptsVersionBefore;
    version?: ScriptsVersionBefore;
    /**
     * Run AFTER bump the package version
     */
    postversion?: string;
    pretest?: ScriptsTest;
    test?: ScriptsTest;
    posttest?: ScriptsTest;
    prestop?: ScriptsStop;
    stop?: ScriptsStop;
    poststop?: ScriptsStop;
    prestart?: ScriptsStart;
    start?: ScriptsStart;
    poststart?: ScriptsStart;
    prerestart?: ScriptsRestart;
    restart?: ScriptsRestart;
    postrestart?: ScriptsRestart;
    [k: string]: string;
  };
  /**
   * A 'config' hash can be used to set configuration parameters used in package scripts that persist across upgrades.
   */
  config?: {
    [k: string]: any;
  };
  dependencies?: Dependency;
  devDependencies?: Dependency;
  optionalDependencies?: Dependency;
  peerDependencies?: Dependency;
  engines?: {
    [k: string]: string;
  };
  engineStrict?: boolean;
  /**
   * You can specify which operating systems your module will run on
   */
  os?: string[];
  /**
   * If your code only runs on certain cpu architectures, you can specify which ones.
   */
  cpu?: string[];
  /**
   * If your package is primarily a command-line application that should be installed globally, then set this value to true to provide a warning if it is installed locally.
   */
  preferGlobal?: boolean;
  /**
   * If set to true, then npm will refuse to publish it.
   */
  private?: boolean;
  publishConfig?: {
    [k: string]: any;
  };
  dist?: {
    shasum?: string;
    tarball?: string;
    [k: string]: any;
  };
  readme?: string;
  /**
   * An ECMAScript module ID that is the primary entry point to your program.
   */
  module?: string;
  /**
   * A module ID with untranspiled code that is the primary entry point to your program.
   */
  esnext?:
    | string
    | {
        [k: string]: any;
      };
  /**
   * Any property starting with _ is valid.
   *
   * This interface was referenced by `CoreProperties`'s JSON-Schema definition
   * via the `patternProperty` "^_".
   */
  [k: string]: {
    [k: string]: any;
  };
}
/**
 * Dependencies are specified with a simple hash of package name to version range. The version range is a string which has one or more space-separated descriptors. Dependencies can also be identified with a tarball or git URL.
 */
export interface Dependency {
  [k: string]: string;
}
export interface JspmDefinition {
  jspm?: CoreProperties;
  [k: string]: any;
}

[CarstenLeue]

First error is on line 68:

[ts] Property 'name' of type 'string' is not assignable to string index type '{ [k: string]: any; }'. [2411]

[bcherny]

Thanks @CarstenLeue! Here's what's happening-

• That schema defines a set of patternProperties:

      "patternProperties": {
        "^_": {
          "description": "Any property starting with _ is valid.",
          "additionalProperties": true,
          "additionalItems": true
        }
      },

• Though we can't fully express patternProperties in TypeScript, we try to do our best
• What that patternProperties definition says is: "In addition to any properties that we explicitly enumerated already, a valid package.json can also have any number of properties that are prefixed with _; each of those properties must be an object, with whatever keys/values it wants".
• This doesn't play well with the properties we've explicitly enumerated already, since not all of them are objects.

So this is a conflict between JSTT's heuristics, and what that schema declares.

I think the best fix here is to replace the patternProperties section with a more lenient one:

      "patternProperties": {
        "^_": {
          "description": "Any property starting with _ is valid.",
          "type": "any"
        }
      },

This is a more correct definition, since _-prefixed package.json properties don't have to be objects.

[G-Rath]

@bcherny any isn't a valid type in JSON schema, meaning this solution won't work.

Do you have any other suggestions on how this could be resolved?

tsType: "any" will do it, but wondering if there is any other way?

[awlayton]

If you omit type then any type is allowed. Just do:

      "patternProperties": {
        "^_": {
          "description": "Any property starting with _ is valid.",
        }
      }