hassamali
Mocking with s3 ex_aws_s3
I want to mock the test with s3 library just to make sure my module is working. This is what i have done so far but i don’t want to use aws keys and secret what else i need to do so my testing scenario don’t use the keys and just test the module
uploads_test.ex
defmodule SignatureWeb.UploadsTest do
use ExUnit.Case, async: false
alias Signature.Uploads
import Mox
setup :verify_on_exit!
describe "upload/1" do
test "write s3 bucket with file and path name and return ok with s3 path" do
content = "signature"
SignatureWeb.ExAwsHttpMock
|> expect(:request, 1, fn _method, _url, _body, _headers, _opts ->
{:ok, %{status_code: 200}}
end)
assert Uploads.upload(content) == {:ok, "signatures/signature"}
end
end
end
uploads.ex ( upload module which logic i want to test in test )
defmodule SignatureWeb.Uploads do
def upload(content) do
# path to bucket + filename
s3_path = "signatures/#{content}"
bucket_name =
:email_messaging
|> Application.fetch_env!(__MODULE__)
|> Keyword.fetch!(:bucket_name)
bucket_name
|> ExAws.S3.put_object(s3_path, content)
|> ExAws.request()
|> handle_aws_response(s3_path)
end
defp handle_aws_response({:ok, _}, s3_path), do: {:ok, s3_path}
defp handle_aws_response({:error, reason}, _), do: {:error, reason}
end
Most Liked
zgore
For those who are still wondering, yes it’s possible to use mock with ExAws without wrapping ExAws.request/2 in another module in order to mock it.
To do so, I read how they are testing their own module : ExAws Github
In fact, they are mocking the HTTP client underneath.
We can do exactly the same thing and mock the HTTP client in our tests.
In the business logic code:
...
response =
bucket_name
|> S3.get_object(filename_path)
|> ExAws.request(get_ex_aws_request_config_override())
...
def get_ex_aws_request_config_override,
do: Application.get_env(:ex_aws, :request_config_override)
config.exs:
...
config :ex_aws,
...
# note: it's a custom config, ex_aws will not take it in account directly
request_config_override: %{}
...
test.exs:
...
config :ex_aws,
request_config_override: %{
http_client: ExAws.Request.HttpMock,
access_key_id: "AKIAIOSFODNN7EXAMPLE",
secret_access_key: "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY"
}
...
In the test code:
stub(ExAws.Request.HttpMock, :request, fn
_method, _url, _body, _headers, _opts ->
# whatever you want to return, example:
{:ok, %{status_code: 200, body: ""}}
end)
I hope it will help !








