AWS SDK S3 mocking

main.go

package main

import (
	"fmt"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/aws/aws-sdk-go/service/s3/s3iface"
)

func main() {

	svc := NewS3("http://beep.boop")

	input := &s3.GetObjectInput{
		Bucket: aws.String("foo"),
		Key:    aws.String("bar"),
	}
	resp, err := svc.GetObject(input)
	if err != nil {

		panic(err)
	}

	fmt.Println(resp)
}

func NewS3(uri string) ObjectStore {

	// TODO Add URI to session
	sess := session.Must(session.NewSession())
	client := s3.New(sess)

	return ObjectStore{
		Client: client,
		URL:    uri,
	}
}

type ObjectStore struct {
	Client s3iface.S3API
	URL    string
}

func (svc ObjectStore) GetObject(in *s3.GetObjectInput) (*s3.GetObjectOutput, error) {

	return svc.Client.GetObject(in)
}

s3_test.go

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/aws/aws-sdk-go/service/s3/s3iface"
)

func TestGetObject(t *testing.T) {

	// Create mock receiver
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "Hello, client")
	}))
	defer ts.Close()

	// Replaces NewS3
	svc := ObjectStore{
		Client: mockGetObject{Resp: s3.GetObjectOutput{}},
		URL:    ts.URL,
	}

	input := &s3.GetObjectInput{
		Bucket: aws.String("foo"),
		Key:    aws.String("bar"),
	}
	resp, err := svc.GetObject(input)
	if err != nil {

		t.Fatal(err)
	}

	t.Log(resp)
}

type mockGetObject struct {
	s3iface.S3API
	Resp s3.GetObjectOutput
}

func (m mockGetObject) GetObject(in *s3.GetObjectInput) (*s3.GetObjectOutput, error) {

	return &m.Resp, nil
}