Swagger Combine

Combines multiple Swagger schemas into one dereferenced schema.

Install

$ npm install --save swagger-combine

Globally for CLI usage

$ npm install -g swagger-combine

Usage

const swaggerCombine = require('swagger-combine');

swaggerCombine('docs/swagger.json')
    .then(res => console.log(JSON.stringify(res)))
    .catch(err => console.error(err));

Swagger Combine returns a promise by default. Alternatively a callback can be passed as second argument:

swaggerCombine('docs/swagger.json', (err, res) => {
  if (err) console.error(err);
  else console.log(JSON.stringify(res));
});

Middleware

const swaggerCombine = require('swagger-combine');
const app = require('express')();

app.get('/swagger.json', swaggerCombine.middleware('docs/swagger.json'));
app.get('/swagger.yaml', swaggerCombine.middleware('docs/swagger.json', { format: 'yaml' }));
app.listen(3333);

The middleware runs the combine function on every request. Since Swagger documentations tend not to change that frequently, the use of a caching mechanism like apicache is encouraged in conjungtion with this middleware.

Async Middleware

const swaggerCombine = require('swagger-combine');
const app = require('express')();

(async function() {
  try {
    app.get('/swagger.json', await swaggerCombine.middlewareAsync('docs/swagger.json'));
    app.get('/swagger.yaml', await swaggerCombine.middlewareAsync('docs/swagger.json', { format: 'yaml' }));
  } catch (e) {
    console.error(e);
  }

  app.listen(3333);
})();

CLI

$ swagger-combine config.json

Help

$ swagger-combine -h

Save to File

$ swagger-combine config.json -o combinedSchema.json

YAML Output

The output is in YAML if the output filename ends with .yaml or .yml:

$ swagger-combine config.json -o combinedSchema.yaml

Alternatively the --format or -f argument can be used:

$ swagger-combine config.json -f yaml

Configuration

• Swagger Combine requires one configuration schema which resembles a standard Swagger schema except for an additional apis field.
• Since this module uses Swagger Parser and JSON Schema $Ref Parser internally the schema can be passed to Swagger Combine as a file path, a URL or a JS object.
• All $ref fields in the configuration schema are getting dereferenced.
• The default path for the configuration file is docs/swagger.json.
• The configuration file can be JSON or YAML.

Basic Configuration

swagger.json

{
  "swagger": "2.0",
  "info": {
    "title": "Basic Swagger Combine Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json"
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    },
    {
      "url": "https://api.apis.guru/v2/specs/deutschebahn.com/betriebsstellen/v1/swagger.json",
      "paths": {
        "base": "/bahn"
      }
    }
  ]
}

swagger.yaml

swagger: '2.0'
info:
  title: Basic Swagger Combine Example
  version: 1.0.0
apis:
  - url: 'http://petstore.swagger.io/v2/swagger.json'
  - url: 'https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml'
  - url: 'https://api.apis.guru/v2/specs/deutschebahn.com/betriebsstellen/v1/swagger.json'
    paths:
      base: '/bahn'

All example configurations are located in the examples folder.

Filtering Paths

Paths can be filtered by using an array of paths and regex strings to exclude or include.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Filter Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "exclude": [
          "/pet/{petId}",
          "/pet.put"
        ]
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml",
      "paths": {
        "include": [
          "/users/{userId}/publications",
          "/me.get"
        ]
      }
    }
  ]
}

Example of using Regex Strings (in combination with path string)

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Filter Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "exclude": [
          ".*\{petId\}.get"
        ]
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml",
      "paths": {
        "include": [
          ".*?/publications(/.*)?",
          "/me.get"
        ]
      }
    }
  ]
}

Filtering Parameters

Parameters can be filtered by specifying the path and the parameter name as to exclude or include as key/value pairs in paths.parameters.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Filter Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "parameters": {
          "exclude": {
            "/pet/findByStatus": "status"
          }
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml",
      "paths": {
        "include": [
          "/users/{userId}/publications",
          "/publications/{publicationId}/posts",
          "/me.get"
        ],
        "parameters": {
          "include": {
            "/publications/{publicationId}/posts.post": "publicationId"
          }
        }
      }
    }
  ]
}

Base Path

The base path for each Swagger schema can be set by base:

{
  "swagger": "2.0",
  "info": {
    "title": "Basic Swagger Combine Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    },
    {
      "url": "https://api.apis.guru/v2/specs/deutschebahn.com/betriebsstellen/v1/swagger.json",
      "paths": {
        "base": "/bahn"
      }
    }
  ]
}

Base path definition in Swagger schemas is ignored by default and the processing can be enabled individually by setting useBasePath. When enabled, the base path and path information is combinded during processing. The option can also be enabled in general (see below). If base is set, the useBasePath is ignored.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine simple Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "useBasePath": true
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

Renaming Paths

Paths can be renamed by specifying the path to rename and the new path name as key/value pairs in paths.rename. This will replace each key matched by path with the new value.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine simple Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "rename": {
          "/pet/{petId}": "/pet/alive/{petId}"
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

Paths can also be replaced by regular expressions and functions.

To configure this, it's necessary to use an array like structure instead of an object with key/value pairs to ensure the order of replacements.

In the swagger.json file only "renaming" and/or a string like regular expression can be used. For regular expression objects or functions the (swagger)json configuration must be generated by javascript and used as input parameter of the swaggerCombine function.

The next example equals the simple example above but used an extended configuration style.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine simple Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "rename": [
          { 
            "type": "rename",
            "from": "/pet/{petId}",
            "to": "/pet/alive/{petId}"
          } 
        ]
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

To change the basePath of all paths a regular expression can be used.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Rename by regular expression Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "rename": [
          { 
            "type": "regex",
            "from": "^\/pet\/(.*)",
            "to": "/pet/alive/$1"
          } 
        ]
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

An example of dynamic generated configuration and renamings with regular expressions and functions.

const swaggerJson = {
  swagger: "2.0",
  info: {
    title: "Swagger Combine Rename by regular expression Example",
    version: "1.0.0"
  },
  apis: [
    {
      url: "http://petstore.swagger.io/v2/swagger.json",
      paths: {
        rename: [
          { 
            type: "regex",
            from: /\/pet\/(.*)/,
            to: "/pet/alive/$1"
          },
          { 
            type: "function",
            to: (path) => path === "/pet/alive/{petId}" ? "/pet/alive/{petAliveId}" : path
          }
        ]
      }
    },
    {
      url: "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

swaggerCombine(swaggerJson)
...

Renaming Tags

Tags can be renamed in the same manner as paths with simple, object like configuration style, using the tags.rename field.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json"
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml",
      "tags": {
        "rename": {
          "Users": "People"
        }
      }
    }
  ]
}

Renaming Path OperationIds

When merging different swagger definitions there are situations were the operationIds used in these separate swaggers could collide. If this is the case and changing source isn't desired or possible. OperationIds can be renamed by specifying the existing id to rename and the new id as key/value pairs in operationIds.rename.

This will replace each operationId matched by the provided key with the new value.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Simple OperationId Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "operationIds": {
        "rename": {
          "addPet": "createPet"
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

Adding Tags

Tags can be added to all operations in a schema, using the tags.add field.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "tags": {
        "add": [
          "pet"
        ]
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml",
      "tags": {
        "add": [
          "medium"
        ]
      }
    }
  ]
}

Renaming Security Definitions

Security definitions can be renamed like paths (simple) and tags in the securityDefinitions.rename field. All usages of the security definition in the paths are renamed as well.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Rename Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "securityDefinitions": {
        "rename": {
          "api_key": "KEY"
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

Path Security

Security can be specified per path using the paths.security field.

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Security Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "paths": {
        "security": {
          "/store/order": {
            "petstore_auth": [
              "write:pets",
              "read:pets"
            ]
          },
          "/store/order/{orderId}.delete": {
            "petstore_auth": [
               "write:pets",
               "read:pets"
             ]
          }
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml"
    }
  ]
}

Authentication & Request Headers

To retrieve Swagger schemas that are access protected, basic auth information (username and password) or any headers to be sent with the http request can be specified:

{
  "swagger": "2.0",
  "info": {
    "title": "Swagger Combine Authentication Example",
    "version": "1.0.0"
  },
  "apis": [
    {
      "url": "http://petstore.swagger.io/v2/swagger.json",
      "resolve": {
        "http": {
          "auth": {
            "username": "admin",
            "password": "secret12345"
          }
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/medium.com/1.0.0/swagger.yaml",
      "resolve": {
        "http": {
          "headers": {
            "authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6ImFkbWluIiwiYWRtaW4iOnRydWV9.44lJS0jlltzcglq7vgjXMXYRTecBxseN3Dec_LO_osI"
          }
        }
      }
    },
    {
      "url": "https://api.apis.guru/v2/specs/deutschebahn.com/betriebsstellen/v1/swagger.json",
      "resolve": {
        "http": {
          "headers": {
            "authorization": "Basic YWRtaW46c2VjcmV0MTIz"
          }
        }
      }
    }
  ]
}

For all possible resolve options have a look at the documentation of json-schema-ref-parser.

API

swaggerCombine(config, [options], [callback])

Returns promise with dereferenced and combined schema.

config string|object

URL/path to config schema file or config schema object.

Default: docs/swagger.json

options object (optional)

• format - string

  Content type of the response. yaml or json (default).

• continueOnError - boolean

  Continue if Swagger configs cannot be resolved or are invalid (default: false). No warning or error message is returned if this option is enabled.

• continueOnConflictingPaths - boolean

  Continue if Swagger schemas have conflicting paths (default: false). An error is only thrown if conflicting paths also have conflicting operations (e.g. if two Swagger schemas both have /pets.get and /pets.get defined).

See JSON Schema $Ref Parser Options for a complete list of options.

• useBasePath - boolean (default: false)

  The base path defintion in Swagger schemas is ignored by default. To respect the base path during combination, configure useBasePath in general or for individual Swagger schemas.

• includeGlobalTags - boolean (default: false)

  Combine global tags (set on the root level of the schemas) as well.

callback function(err, combinedSchema) (optional)

Callback with error and the dereferenced and combined schema.

swaggerCombine.middleware(config, [options])

Returns function(req, res, next) for usage as middleware.

config string|object

see above

options object (optional)

see above

swaggerCombine.middlewareAsync(config, [options])

Returns a promise yielding a function(req, res, next) for usage as middleware.

config string|object

see above

options object (optional)

see above