Testing the Application

HTTP Basics

As an introduction to HTTP, we recommend reading the HTTP section of Mozilla Developer Network (MDN) documentation. Especially, about the structure of HTTP messages, request methods and response status codes.

Let's start a Genie server on port 8000 for our application.

pkg> activate .
julia> using Genie
julia> Genie.loadapp()
julia> up(8000)

We can create requests to the server by accessing URLs in the browser. Alternatively, we can send requests directly to the server using the HTTP.jl library.

julia> using HTTP
julia> base = "http://localhost:8000"

The base variable should point to the base URL where we host our application, such as localhost or server where have deployed the application.

HTML Views

Listing All Items

By sending a GET request to the /items the server returns the HTML that shows the Items page.

julia> HTTP.request("GET", "$(base)/items")

HTTP.Messages.Response:
"""
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
Server: Genie/Julia/1.6.1
Transfer-Encoding: chunked

<!DOCTYPE html>..."""

Adding New Items

Warning

Currently, posting forms programmatically does not work for an unknown reason.

We can also POST forms programmatically.

julia> form = HTTP.Form(Dict("a"=>"Hello World", "b"=>"1"))
julia> HTTP.request("POST", "$(base)/items", [], form)

JSON API

We have also implemented a JSON-based API on the application on the path /api/items. The API is intended for programmatic use and access to the application. We will use the JSON3 library for encoding Julia data structures into JSON payloads.

julia> using JSON3

Internally, a Genie application maps posted JSON objects to defined Julia data structures.

Retrieving All Items

We can request all items from the API.

julia> HTTP.request("GET", "$(base)/api/items")

We receive an HTTP response with application/json content type in the header and a JSON object in the body.

HTTP.Messages.Response:
"""
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Server: Genie/Julia/1.6.1
Transfer-Encoding: chunked

[{"id":{"value":1},"a":"Hello World","b":1}]"""

Adding New Items

We can also add new item by sending a JSON-formatted payload to the API.

julia> payload = JSON3.write(Dict(:a=>"Hello World", :b=>1))
julia> HTTP.request("POST", "$(base)/api/items",
           [("Content-Type", "application/json")], payload)

HTTP.Messages.Response:
"""
HTTP/1.1 201 Created
Content-Type: application/json; charset=utf-8
Server: Genie/Julia/1.6.1
Transfer-Encoding: chunked

"Created""""

Retrieving a Specific Item

We can query a specific item using the API.

julia> HTTP.request("GET", "$(base)/api/items/1")

HTTP.Messages.Response:
"""
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Server: Genie/Julia/1.6.1
Transfer-Encoding: chunked

{"id":{"value":1},"a":"Hello World","b":1}"""

Updating a Specific Item

We can also update a specific item using the API.

julia> payload = JSON3.write(Dict(:a=>"Hello World Again", :b=>2))
julia> HTTP.request("PUT", "$(base)/api/items/1",
           [("Content-Type", "application/json")], payload)

HTTP.Messages.Response:
"""
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Server: Genie/Julia/1.6.1
Transfer-Encoding: chunked

"""""

Removing Specific Item

Finally, we can remove a specific item using the API.

julia> HTTP.request("DELETE", "$(base)/api/items/1")

HTTP.Messages.Response:
"""
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Server: Genie/Julia/1.6.1
Transfer-Encoding: chunked

"Deleted""""

Unit Tests

We can run the unit tests from the package mode in Julia REPL.

(@v1.6) pkg> activate .
(GenieWebApp) pkg> test

The test command will execute test/runtests.jl script, which sets the Genie environment to test, creates a temporary database, loads the application, and runs a server. The unit tests send HTTP requests to the server and check for correct status codes.