datatype-expansion

RAML Data Type Expansion

Often, tools need the full expansion of RAML data types where there are no references. This module gives you a utility tool to expand a given type and create a canonical form.

Installation

NPM

npm install datatype-expansion

RAML type expanded form

The RAML expanded form for a RAML type, resolves references and fills missing information to compute a fully expanded representation of the type. The form and the algorithm to compute is documented here.

Usage

The Node.js interface for the library offers the expandedForm function to compute the expanded form. It accepts an in-memory JSON representation of the type, the types mapping and an optional callback function or options object. It returns the canonical form or an exception. The following options are supported:

• callback: Provides a callback function via the options object.
• topLevel (default: any): The default RAML type to use when base type is not explicit and cannot be inferred. It can be any or string, depending on whether the type comes from the body of a RAML service.
• trackOriginalType (default: false): Controls whether expansion should track the original type in a property called originalType when expanding a type reference.

Sync API

const tools = require('datatype-expansion');

const typesContext = {
  Song: {
    properties: {
      title: 'string',
      length: 'number'
    }
  },
  Album: {
    properties: {
      title: 'string',
      songs: 'Songs.Song[]'
    }
  }
};
const expanded = tools.expandedForm(typesContext['Album'], typesContext)
console.log(JSON.stringify(expanded,null,2));

Callback API

const tools = require('datatype-expansion');

const typesContext = {
  Song: {
    properties: {
      title: 'string',
      length: 'number'
    }
  },
  Album: {
    properties: {
      title: 'string',
      songs: 'Songs.Song[]'
    }
  }
};
tools.expandedForm(typesContext['Album'], typesContext, function(err, expanded) {
  // expanded contains the computed expanded form
  console.log(JSON.stringify(expanded,null,2));
});

Result

{
  "properties": {
    "title": {
      "type": "string",
      "required": true
    },
    "songs": {
      "type": "array",
      "items": {
        "properties": {
          "title": {
            "type": "string",
            "required": true
          },
          "length": {
            "type": "number",
            "required": true
          }
        },
        "additionalProperties": true,
        "type": "object",
        "required": true
      },
      "required": true
    }
  },
  "additionalProperties": true,
  "type": "object",
  "required": true
}

RAML type canonical form

The canonical form computes inheritance and pushes unions to the top level of the type structure of an expanded RAML type. It is described in the documentation section of this repository.

Usage

The Node.js version of the canonical form function is defined in the canonicalForm function of the library module. It accepts a JSON in-memory representation of an expanded RAML type and an optional callback function or options object. It returns the canonical form or an exception. The following options are supported:

• callback: Provides a callback function via the options object.
• hoistUnions (default: true): Controls whether canonicalization should hoist unions to the top level of the type form. When enabled, union can only appear as the top-level type, and the associated type alternatives are the permutation of any nested unions in the input type. When disabled, unions remain nested.

Sync API

const tools = require('datatype-expansion');

const typesContext = {
  SimpleUnion: {
    properties: {
      a: 'string',
      b: 'number | string'
    }
  },
};
const expanded = tools.expandedForm(typesContext['SimpleUnion'], typesContext)
const canonical = tools.canonicalForm(expanded)
console.log(JSON.stringify(canonical,null,2));

Callback API

const tools = require('datatype-expansion');

const typesContext = {
  SimpleUnion: {
    properties: {
      a: 'string',
      b: 'number | string'
    }
  },
};
tools.expandedForm(typesContext['Songs.Album'], typesContext, function(err, expanded) {
   tools.canonicalForm(expanded, function(err, canonical) {
    // canonical contains the computed canonical form
    console.log(canonical);
   });
});

Result

{
  "type": "union",
  "additionalProperties": true,
  "anyOf": [
    {
      "properties": {
        "a": {
          "type": "string",
          "required": true
        },
        "b": {
          "type": "number",
          "required": true
        }
      },
      "type": "object",
      "additionalProperties": true
    },
    {
      "properties": {
        "a": {
          "type": "string",
          "required": true
        },
        "b": {
          "type": "string",
          "required": true
        }
      },
      "type": "object",
      "additionalProperties": true
    }
  ]
}

Browser usage

Include it via unpkg ( if you don't use a bundler like webpack )

<script src="https://unpkg.com/datatype-expansion"></script>

It gets exported as expansion

expansion.expandedForm('string', {})

Running tests

Tests for the library can be run using:

$ npm run test