CODEWITHSUNDEEP
jsongo
Josh Wilson
Josh Wilson

Reputation: 3745

Go test Difference between maps

I'm trying to run some tests on json objects. Currently I have a function to compare the json string and output an error message if they don't match:

func assertJsonEqual(expected, actual string) bool {
    actualStruct := make(map[string]interface{})
    expectedStruct := make(map[string]interface{})

    json.Unmarshal([]byte(expected), &expectedStruct)
    json.Unmarshal([]byte(actual), &actualStruct)

    if !reflect.DeepEqual(expectedStruct, actualStruct) {
        log.Errorf("Expected: %#v\n but got %#v", expectedStruct, actualStruct)
        return false
    }
    return true
}

The problem is this makes it really hard to see exactly which key is missing or extra in the actual tool. I'm thinking about building a simple diff of the map keys, but am wondering if there is an existing library that already does this?

Upvotes: 1

Views: 1932

Answers (1)

evanmcdonnal
evanmcdonnal

Reputation: 48086

There's not an existing function, it's like 5 lines of code.

diff := &[]string{} // initialize some storage for the diff

for _, k := range map1 { // range over one of the maps
    if _, ok := map2[k]; !ok { // check if the key from the first map exists in the second
        diff = append(diff, k)
    }
}

Upvotes: 2

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