Jest transformer for .http files

Literature and references

About jest transformers

https://jestjs.io/docs/code-transformation

About .http Files

• https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/test/http-files.md
• https://marketplace.visualstudio.com/items?itemName=humao.rest-client
• https://www.jetbrains.com/help/idea/exploring-http-syntax.html

Usage

Install the npm package as dev dependency: jest-dot-http-files

It works by exporting a jest transformer. Here is a simplified way to use it:

// jest.config.js

export default {
  moduleFileExtensions: ['http'],
  testMatch: ['**/*.http'],
  transform: {
    '\\.http$': 'jest-dot-http-files/transformer'
  }
}

Deviations from the existing literature

Global variables

Variables starting with @@ are held in the global scope, meaning they are available to all requests.

Meta variables

Meta variables are defined in the request scope within comments, similarly to jsdoc.

The @title meta variable

Overrides the test title. This variable is optional.

# @title My meaningful test title.
GET http://foo/bar

The @name meta variable

Used to name a request. Named requests can be used in interpolations. This variable is optional.

# @name foo
GET http://foo/bar

Accessing the named request:

GET http://foo/{{foo.$.response.body.id}}

The @only meta variable

Meaning: runs only this request.

# @only
GET http://foo/bar

The @skip meta variable

Meaning: don't run this request.

# @skip
GET http://foo/bar

Functions

Functions are used within interpolations {{...}}.

The $guid function

Generates a random v4 UUID.

The $uuid function

Alias to $guid.

The $randomInt function

Generates a random integer number between min and max.

GET http://foo/{{$randomInt 10 20}}

The $datetime function

Generates a date/time string: {{$datetime <format> [offset unit]}}

Format:

• rfc1123:
• iso8601:
• or a custom format, e.g: "dd-MM-yyyy"

Offset unit:

• y = Year
• M = Month
• w = Week
• d = Day
• h = Hour
• m = Minute
• s = Second

Example:

# adds one year to current date
GET http://foo/{{$datetime iso8601 1 y}}

A note on "assertions"

Assertions are made using jest snapshots.

The @ignoreHeaders meta variable

A regex pattern string.

Use it to specify what headers (both request and response) to ignore for snapshot assertion. The "age" and "date" headers are always ignored.

# @ignoreHeaders ^(x-request-id|x-vendor-.*)
GET http://foo/bar

The @ignore meta variable

Use it to specify what json-paths to ignore for snapshot assertion. The json-path is related to the named-request's request/response.

This variable is accumulative and forms a list, meaning you can ignore more than one path per request.

# @ignore $.response.body.id
# @ignore $.response.body.completed
GET http://foo/bar

The @expect meta variable

Asserts a json-path against a constant. The json-path is related to the named-request's request/response.

This variable is accumulative and forms a list, meaning you can have many assertions.

# @expect $.response.status 200
# @expect $.response.statusText "OK"
GET http://foo/bar

The @status meta variable

Alias to @expect $.response.status <statusCode> and ( optionally ) @expect $.response.statusText "<statusText>"

# @status 200 "OK"
GET http://foo/bar

or the status code only

# @status 200
GET http://foo/bar

The @throws meta variable

# @throws
GET http://foo/bar

or with a regex pattern

# @throws .*error.*
GET http://foo/bar

Expects the request to throw an error.

This is helpful to test negative cases, for example:

# @titles Tests that the response is not 500
# @status 500
# @throws
GET http://foo/bar

---

See also

• Language support for vscode:
  • Repository: https://github.com/andreventuravale/vscode-dot-http-files
  • Marketplace: https://marketplace.visualstudio.com/items?itemName=AndreValeOutlook.vscode-dot-http-files