Dredd Transactions

Dredd Transactions library compiles HTTP Transactions (simple Request-Response pairs) from API description document.

Maintained Fork

This package is maintained in the stacklych/dredd fork. The original Apiary repository was archived on November 8, 2024. The package name remains dredd-transactions in source metadata for compatibility with the existing workspace and import paths; scoped package publishing should be handled as a separate release migration.

Note: To better understand emphasized terms in this documentation, please refer to the Glossary of Terms. All data structures are described using the MSON format.

This project supersedes Blueprint Transactions library.

Features

• Inherits parameters from parent Resource and Action sections.
• Expands URI Templates.
• Warns on undefined placeholders in URI Templates (both query and path).
• Validates URI parameter types.
• Selects first Request and first Response if multiple are specified in the API description document.
• Compiles OpenAPI 3.1 response-testing transactions from paths and operations.

OpenAPI 3.1 Support

OpenAPI 3.1 documents are compiled through a dedicated compiler path instead of the legacy API Elements OpenAPI 3 parser. The supported subset includes:

• path and query parameters using example, first examples entry, default, or first enum value
• path simple and query form parameter serialization, including arrays, objects, and explode
• request bodies using the first declared media type and explicit or schema-derived examples
• responses using the first declared media type and explicit or schema-derived examples
• simple local $ref values
• response schemas with dialect handling

For response schemas, Dredd Transactions preserves schema-level $schema, otherwise uses root jsonSchemaDialect, otherwise uses the OpenAPI 3.1 Schema Object dialect URI https://spec.openapis.org/oas/3.1/dialect/base.

The current OpenAPI 3.1 compiler does not implement every OpenAPI 3.1 feature. External references, callbacks, links, webhooks, header or cookie parameters, matrix, label, space-delimited, pipe-delimited, or deep-object parameter serialization, and multipart encoding objects are not yet covered.

Deprecated Features

• Compiles Transaction Name string (vague identifier) for each Transaction.
• Provides Transaction Origin with pointers to API Elements derived from the original API description document.

Note: These features are to be superseded by whatever comes out of the proposal in apiaryio/dredd#227.

Installation

npm install dredd-transactions

Development

Dredd Transactions library is written in JavaScript (ES2015+).

Usage

parse

Parses given OpenAPI 3.0 or OpenAPI 3.1 description document into API Elements with options specific to Dredd. Documents in an unrecognized format produce an API Elements error annotation. Turns any parser failures, including the unexpected ones, into API Elements annotations.

const parse = require('dredd-transactions/parse');
// const { parse } = require('dredd-transactions');

parse('openapi: "3.0.0"\n...', (error, parseResult) => {
  // ...
});

compile

Compiles HTTP Transactions from given API Elements. HTTP Transactions are a backbone data structure to Dredd.

const compile = require('dredd-transactions/compile');
// const { compile } = require('dredd-transactions');

const compileResult = compile(mediaType, apiElements, filename);

Note: The filename argument is optional and about to get deprecated, see #6

Data Structures

Parse Result (object)

Result of parsing.

• mediaType: application/vnd.oai.openapi (string, default, nullable) - Media type of the input format, can be empty in case of some fatal errors
• apiElements (API Elements) - API Elements parse result

Compile Result (object)

Result of compilation. Alongside compiled Transaction objects contains also errors and warnings, mainly from API description parser.

• mediaType: application/vnd.oai.openapi (string, default, nullable) - Media type of the input format, defaults to the OpenAPI media type. Can be empty in case of some fatal errors.
• transactions (array[Transaction]) - Compiled HTTP Transactions.
• annotations (array[Annotation]) - Errors and warnings which occurred during parsing of the API description or during compilation of transactions.

Transaction (object)

Represents a single HTTP Transaction (Request-Response pair) and its location in the API description document. The location is provided in two forms, both deprecated as of now:

• name - String representation, both human- and machine-readable.
• origin - Object of references to nodes of API Elements derived from the original API description document.

Note: These two forms of locating HTTP Transactions are to be superseded by whatever comes out of the proposal in apiaryio/dredd#227.

Properties

• request (object) - HTTP Request as described in API description document.
  • method
  • uri: /message (string) - Informative URI of the Request.
  • headers (array) - List of HTTP headers in their original order, with the original casing of the header name, including multiple headers of the same name.
    • (object)
      • name: Content-Type (string)
      • value: text/plain (string)
  • body: Hello world!\n (string)
• response (object) - Expected HTTP Response as described in API description document.
  • status: 200 (string)
  • headers (array) - List of HTTP headers in their original order, with the original casing of the header name, including multiple headers of the same name.
    • (object)
      • name: Content-Type (string)
      • value: text/plain (string)
  • body (string, optional)
  • schema (string, optional)

Deprecated Properties

• name: Hello world! > Retrieve Message (string) - Transaction Name, non-deterministic breadcrumb location of the HTTP Transaction within the API description document.
• origin (object) - Object of references to nodes of API Elements derived from the original API description document.
  • filename: ./api-description.yaml (string)
  • apiName: My Api (string)
  • resourceGroupName: Greetings (string)
  • resourceName: Hello, world! (string)
  • actionName: Retrieve Message (string)
  • exampleName: First example (string)

Note: These properties are to be superseded by whatever comes out of the proposal in apiaryio/dredd#227.

Annotation (object)

Description of an error or warning which occurred during parsing of the API description or during compilation of transactions.

Properties

• type (enum[string])
  • error
  • warning
• component (enum[string]) - In which component of the compilation process the annotation occurred
  • apiDescriptionParser
  • parametersValidation
  • uriTemplateExpansion
• message (string) - Textual annotation. This is – in most cases – a human-readable message to be displayed to user
• location (array, fixed, nullable) - Location of the annotation in the source file, represented by a single range of line and column number pairs if available, or by null otherwise
  • (array) - Start location
    • (number) - Line number
    • (number) - Column number
  • (array) - End location
    • (number) - Line number
    • (number) - Column number

Deprecated Properties

• name: Hello world! > Retrieve Message (string) - Transaction Name, non-deterministic breadcrumb location of the relevant HTTP Transaction within the API description document.
• origin (object) - Object of references to nodes of API Elements derived from the original API description document.
  • filename: ./api-description.yaml (string)
  • apiName: My Api (string)
  • resourceGroupName: Greetings (string)
  • resourceName: Hello, world! (string)
  • actionName: Retrieve Message (string)
  • exampleName: First example (string)

Note: These properties are to be superseded by whatever comes out of the proposal in apiaryio/dredd#227.