bank

An oversimplified bank application to illustrate using property-based testing with HTTP APIs.

Build

$ rebar3 compile

OpenAPI specification

The API specification is defined in the openapi.yaml file.

It is also published in SwaggerHub for a nicer and more user-friendly view of the API.

OpenAPI generator

Install the OpenAPI generator by running:

curl https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/bin/utils/openapi-generator-cli.sh > /usr/local/bin/openapitools/openapi-generator-cli
chmod u+x /usr/local/bin/openapi-generator-cli

Generating the HTTP server

Once the OpenAPI generate CLI is available in your path run the following command to generate the boilerplate code for your HTTP server.

openapi-generator-cli generate -g erlang-server -i openapi.yaml -o apps/bank --additional-properties packageName=bank

Edit the bank.app.src file so that it indicates the bank_app module in the mod entry: {mod, {bank_app, []}.

Then change the bank_app:start/2 function as follows:

start(_StartType, _StartArgs) ->
  Opts = #{transport_opts => [{ip,{127,0,0,1}},{port,8080}]},
  bank_server:start(bank_http_server, Opts),
  bank_sup:start_link().

Generating the property-based tests

Run the following command to generate the property-based testing application:

openapi-generator-cli generate -g erlang-proper -i openapi.yaml -o apps/bank_proper --additional-properties packageName=bank_proper

Since the HTTP server is started in port 8080 we will need to change the value for the host environment variable in bank_proper.app.src to {host, "http://localhost:8080"}.

Running the poper tests

First start the bank application's HTTP server with rebar3 shell from the top level directory.

Then start the proper tests by running rebar3 proper in the apps/bank_proper directory.