go-test / deep

Golang deep variable equality test that returns human-readable differences
MIT License
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deep-equals golang golang-testing variable-equality

Deep Variable Equality for Humans

Go Report Card Coverage Status Go Reference

This package provides a single function: deep.Equal. It's like reflect.DeepEqual but much friendlier to humans (or any sentient being) for two reason:

reflect.DeepEqual is good (like all things Golang!), but it's a game of Hunt the Wumpus. For large maps, slices, and structs, finding the difference is difficult.

deep.Equal doesn't play games with you, it lists the differences:

package main_test

import (
    "testing"
    "github.com/go-test/deep"
)

type T struct {
    Name    string
    Numbers []float64
}

func TestDeepEqual(t *testing.T) {
    // Can you spot the difference?
    t1 := T{
        Name:    "Isabella",
        Numbers: []float64{1.13459, 2.29343, 3.010100010},
    }
    t2 := T{
        Name:    "Isabella",
        Numbers: []float64{1.13459, 2.29843, 3.010100010},
    }

    if diff := deep.Equal(t1, t2); diff != nil {
        t.Error(diff)
    }
}
$ go test
--- FAIL: TestDeepEqual (0.00s)
        main_test.go:25: [Numbers.slice[1]: 2.29343 != 2.29843]

The difference is in Numbers.slice[1]: the two values aren't equal using Go ==.