golang-handlerinspector

README

Handler Inspector

A tool to create http.Handler values using the builder pattern with an included inspector interface for http tests.

Installation

Use

go get github.com/dodevops/golang-handlerinspector@latest

to install and require the module.

Usage

Building http.Handler objects

This module includes a tool to create http.Handler objects using the builder pattern. The returned object will handle http requests using a set of rules. Each rule is tested against a list of conditions. If all these conditions match, the response is generated.

Example:

builder.NewBuilder().
    WithRule(
        handlerinspector.NewRule("test-endpoint").
            WithCondition(handlerinspector.HasPath("/api/endpoint")).
            WithCondition(handlerinspector.HasMethod("GET")).
            WithCondition(handlerinspector.HasHeader("Authorization", "Bearer TESTTOKEN")).
            ReturnBody("[]").
            ReturnHeader("Content-Type", "application/json").
            Build(),
    )

Inspecting the generated handler

In a test context using httptest's server type, the supplied Inspector type can be used to inspect the calls to the previously generated http.Handler and use asserts on it.

Example:

h := builder.NewBuilder().
    WithRule(
        handlerinspector.NewRule("test-endpoint").
            WithCondition(handlerinspector.HasPath("/api/endpoint")).
            WithCondition(handlerinspector.HasMethod("GET")).
            WithCondition(handlerinspector.HasHeader("Authorization", "Bearer TESTTOKEN")).
            ReturnBody("[]").
            ReturnHeader("Content-Type", "application/json").
            Build(),
    )
s := httptest.NewServer(h.Build())
defer s.Close()

// (...)

i := inspector.NewInspector(h)
assert.Equal(t, i.Failed(), false)
assert.Equal(t, i.AllWereCalled(), true)

Motivation

While creating a test suite for our vmware-rest-proxy we were looking for a nice mock server implementation only to find it in a Golang core package, which was a pleasant suprise.

However, creating http.Handlers for it and especially testing them was a bit of a hassle, and we didn't find any easy tool to achieve it.

Thus, here's Handler Inspector. It's currently designed to meet our needs for the vmware-rest-proxy, but can easily be extended if other needs arise.