https://github.com/akshayjshah/attest

Type-safe assertion helpers for Go
https://github.com/akshayjshah/attest

assert generics go testing

Last synced: 12 days ago
JSON representation

Type-safe assertion helpers for Go

• Host: GitHub
• URL: https://github.com/akshayjshah/attest
• Owner: akshayjshah
• License: mit
• Created: 2022-03-20T21:22:57.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2024-08-09T05:03:56.000Z (3 months ago)
• Last Synced: 2024-10-20T11:43:09.501Z (19 days ago)
• Topics: assert, generics, go, testing
• Language: Go
• Homepage: https://pkg.go.dev/go.akshayshah.org/attest
• Size: 38.1 KB
• Stars: 15
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Contributing: .github/CONTRIBUTING.md
  • License: LICENSE
  • Code of conduct: .github/CODE_OF_CONDUCT.md

Awesome Lists containing this project

README

        
attest

======

[![Build](https://github.com/akshayjshah/attest/actions/workflows/ci.yaml/badge.svg?branch=main)](https://github.com/akshayjshah/attest/actions/workflows/ci.yaml)

[![Report Card](https://goreportcard.com/badge/go.akshayshah.org/attest)](https://goreportcard.com/report/go.akshayshah.org/attest)

[![GoDoc](https://pkg.go.dev/badge/go.akshayshah.org/attest.svg)](https://pkg.go.dev/go.akshayshah.org/attest)

`attest` is a small package of type-safe assertion helpers. Under the hood,

it uses [cmp] for equality testing and diffing. You may enjoy `attest` if you

prefer:

- Type safety: it's impossible to compare values with different types.

- Brevity: assertions usually print diffs rather than full values.

- Minimalism: just a few assertions, not a whole DSL.

- Natural ordering: every assertion uses `got == want` order.

- Interoperability: assertions work with any `cmp.Option`.

## Installation

```

go get go.akshayshah.org/attest

```

## Usage

```go

package main

import (

  "testing"

  "time"

  "go.akshayshah.org/attest"

)

func TestExample(t *testing.T) {

  attest.Equal(t, 1, 1)

  attest.NotEqual(t, 2, 1)

  attest.Approximately(

    t,

    time.Minute - 1, // got

    time.Minute,     // want

    time.Second,     // tolerance

  )

  attest.Zero(t, "")

  attest.Contains(t, []int{0, 1, 2}, 2)

  var err error

  attest.Ok(t, err)

  err = fmt.Errorf("read config: %w", io.EOF)

  attest.Error(t, err)

  attest.ErrorIs(t, err, io.EOF)

  // You can enrich the default failure message.

  attest.Equal(t, 1, 2, attest.Sprintf("integer %s", "addition"))

  // The next two assertions won't compile.

  attest.Equal(t, int64(1), int(1))

  attest.Approximately(t, 9, 10, 0.5)

}

```

Failed assertions usually print a diff. Here's an example using `attest.Equal`:

```

--- FAIL: TestEqual (0.00s)

    attest_test.go:58: got != want

        diff (+got, -want):

          attest.Point{

                X: 1,

        -       Y: 4.2,

        +       Y: 3.5,

          }

```

## Status: Stable

This module is stable. It supports the [two most recent major

releases][go-support-policy] of Go.

Within those parameters, `attest` follows semantic versioning. No

breaking changes will be made without incrementing the major version.

## Legal

Offered under the [MIT license][license].

[cmp]: https://pkg.go.dev/github.com/google/go-cmp/cmp

[go-support-policy]: https://golang.org/doc/devel/release#policy

[license]: https://github.com/akshayjshah/attest/blob/main/LICENSE