go-dynamock

Amazon Dynamo DB Mock Driver for Golang to Test Database Interactions.

Originally forked from https://github.com/gusaul/go-dynamock and added more functionalities with examples:

• QueryInput expectation.
• WithContext expectation to support QueryWithContext.

Install

go get github.com/alext234/go-dynamock

Examples Usage

See the examples directory.

DynamoDB configuration

First of all, change the dynamodb configuration to use the dynamodb interface. see code below:

package main

import (
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/dynamodb"
    "github.com/aws/aws-sdk-go/service/dynamodb/dynamodbiface"
)

type MyDynamo struct {
    Db dynamodbiface.DynamoDBAPI
}

var Dyna *MyDynamo

func ConfigureDynamoDB() {
	Dyna = new(MyDynamo)
	awsSession, _ := session.NewSession(&aws.Config{Region: aws.String("ap-southeast-2")})
	svc := dynamodb.New(awsSession)
	Dyna.Db = dynamodbiface.DynamoDBAPI(svc)
}

the purpose of code above is to make your dynamoDB object can be mocked by dynamock through the dynamodbiface.

Something you may wanna test

package main

import (
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/service/dynamodb"
)

func GetName(id string) (*string, error) {
	parameter := &dynamodb.GetItemInput{
		Key: map[string]*dynamodb.AttributeValue{
			"id": {
				N: aws.String(id),
			},
		},
		TableName: aws.String("employee"),
	}

	response, err := Dyna.Db.GetItem(parameter)
	if err != nil {
		return nil, err
	}

	name := response.Item["name"].S
	return name, nil
}

Test with DynaMock

package examples

import (
	"testing"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/dynamodb"
	dynamock "github.com/alext234/go-dynamock"
)

var mock *dynamock.DynaMock

func init() {
	Dyna = new(MyDynamo)
	Dyna.Db, mock = dynamock.New()
}

func TestGetName(t *testing.T) {
	expectKey := map[string]*dynamodb.AttributeValue{
		"id": {
			N: aws.String("1"),
		},
	}

	expectedResult := aws.String("jaka")
	result := dynamodb.GetItemOutput{
		Item: map[string]*dynamodb.AttributeValue{
			"name": {
				S: expectedResult,
			},
		},
	}

	//lets start dynamock in action
	mock.ExpectGetItem().ToTable("employee").WithKeys(expectKey).WillReturns(result)

	actualResult, _ := GetName("1")
	if actualResult != expectedResult {
		t.Errorf("Test Fail")
	}
}

if you just wanna expect the table

mock.ExpectGetItem().ToTable("employee").WillReturns(result)

or maybe you didn't care with any arguments, you just need to determine the result

mock.ExpectGetItem().WillReturns(result)

and you can do multiple expectations at once, then the expectation will be executed sequentially.

mock.ExpectGetItem().WillReturns(resultOne)
mock.ExpectUpdateItem().WillReturns(resultTwo)
mock.ExpectGetItem().WillReturns(resultThree)

/* Result
the first call of GetItem will return resultOne
the second call of GetItem will return resultThree
and the only call of UpdateItem will return resultTwo */

License

The MIT License