xk6-websockets

This extension adds a PoC Websockets API implementation to k6.

This is meant to try to implement the specification as close as possible without doing stuff that don't make sense in k6 like:

1. not reporting errors
2. not allowing some ports and other security workarounds

It supports additional k6 specific features such as:

• Custom metrics tags
• Cookie jar
• Headers customization
• Support for ping/pong which isn't part of the specification
• Compression Support (The only supported algorithm currently is deflate)

It is implemented using the xk6 system.

Requirements

• Golang 1.19+
• Git
• xk6 (go install go.k6.io/xk6/cmd/xk6@latest)
• curl (downloading the k6 core's linter rule-set)

Getting started

1. Build the k6's binary:

$ make build

2. Run an example:

$ ./k6 run ./examples/test-api.k6.io.js

Discrepancies with the specifications

• binaryType does not have a default value (in contrast to the spec, which suggests "blob" as default), so in order to successfully receive binary messages a binaryType must be explicitly set either to "arraybuffer" (for ArrayBuffer) or "blob" (for Blob).

Contributing

Contributing to this repository is following general k6's contribution guidelines since the long-term goal is to merge this extension into the main k6 repository.

Testing

To run the test you can use the make test target.

Linting

To run the linter you can use the make lint target.

[!IMPORTANT]
By default there is golangci-lint config presented. Since the long-term goal is to merge the module back to the grafana/k6 we use the k6's linter rules. The rule set will be downloaded automatically while the first run of the make lint or you could do that manually by running make linter-config.