10 KiB
Adding Asserts
Our basic Hurl file is now:
# Our first Hurl file, just checking
# that our server is up and running.
GET http://localhost:8080
HTTP/1.1 200
Currently, we're just checking that our home page is responding with a 200 OK
HTTP status code.
But we also want to check the content of our home page, to ensure that everything is ok. To check the response
of an HTTP request with Hurl, we have to describe tests that the response content must pass.
We're already implicitly asserting the response with the line
HTTP/1.1 200
On one hand, we are checking that the HTTP protocol version is 1.1; on the other hand, we are checking that the HTTP status response code is 200.
To do so, we're going to use asserts.
As our endpoint http://localhost:8080 is serving HTML content, it makes sense to use XPath asserts. If we want to test a REST api or any sort of api that serves JSON content, we could use JSONPath asserts instead. There are other type of asserts but every one shares the same structure. So, let's look how to write a XPath asserts.
HTML Body Test
Structure of an assert
An assert consists of a query and a predicate. As we want to test the value of the HTML title tag, we're
going to use the XPath expression string(//head/title)
.
- Asserts are written in an Asserts section, so modify
basic.hurl
file:
# Our first Hurl file, just checking
# that our server is up and running.
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
- Run
basic.hurl
:
$ hurl basic.hurl
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Welcome to Quiz!</title>
<!-- <link rel="stylesheet" href="style.css">
<script src="script.js"></script>-->
</head>
....
</html>
We get the content of the page and there is no error so everything is good!
- Modify the predicate value to "Welcome to Quaz!"
# Our first Hurl file, just checking
# that our server is up and running.
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quaz!"
- Run
basic.hurl
:
$ hurl basic.hurl
error: Assert Failure
--> integration/basic.hurl:6:0
|
6 | xpath "string(//head/title)" == "Welcome to Quaz!"
| actual: string <Welcome to Quiz!>
| expected: string <Welcome to Quaz!>
|
Hurl has failed now and provides informations on which assert is not valid.
Typed predicate
If we decompose our assert, xpath "string(//head/title)"
is the XPath query and == "Welcome to Quiz!"
is our
predicate to test the query against. You can note that predicates values are typed:
xpath "string(//head/title)" == "true"
tests that the XPath expression is returning a string, andxpath "boolean(//head/title)" == true
tests that the XPath expression is returning a boolean
Some queries can also return collections. For instance, the XPath expression //button
is returning all the button
elements present in the DOM. We can use it to ensure that we have exactly two buttons on our home page,
with count
:
- Add a new assert in
basic.hurl
to check the number of buttons:
# Checking our home page:
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
xpath "//button" count == 2
- We can also check each button's title:
# Checking our home page:
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
xpath "//button" count == 2
xpath "string((//button)[1])" contains "Play"
xpath "string((//button)[2])" contains "Create"
XPath queries can sometimes be a little tricky to write but modern browsers can help writing these expressions. Try open the Javascript console of your browser (Firefox, Safari or Chrome) and type
$x("string(//head/title)")
then press Return. You should see the result of your XPath query.
- Run
basic.hurl
and check that every assert has been successful:
$ hurl basic.hurl
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Welcome to Quiz!</title>
<!-- <link rel="stylesheet" href="style.css">
<script src="script.js"></script>-->
</head>
....
</html>
HTTP Headers Test
We are also going to add tests on the HTTP response headers with explicit header
asserts.
As our endpoint is serving UTF-8 encoded HTML content, we can check the value of the Content-Type
response header.
- Add a new assert at the end of
basic.hurl
to test the value of theContent-Type
HTTP header:
# Checking our home page:
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
xpath "//button" count == 2
xpath "string((//button)[1])" contains "Play"
xpath "string((//button)[2])" contains "Create"
# Testing HTTP response headers:
header "Content-Type" == "text/html;charset=UTF-8"
Our HTTP response has only one
Content-Type
header, so we're testing this header value as string. The same header could be present multiple times in an HTTP response, with different values. In this case, theheader
query will return collections and could be tested withcountEqual
orinclude
predicates.
For HTTP headers, we can also use an implicit header assert. You can use indifferently implicit or
explicit header assert: the implicit one allows you to only check the exact value of the header,
while the explicit one allows you to use other predicates (like contains
, startsWith
, matches
etc...).
- Replace the explicit assert with implicit header assert:
# Checking our home page:
GET http://localhost:8080
HTTP/1.1 200
# Implicitely testing response headers:
Content-Type: text/html;charset=UTF-8
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
xpath "//button" count == 2
xpath "string((//button)[1])" contains "Play"
xpath "string((//button)[2])" contains "Create"
The line Content-Type: text/html;charset=UTF-8
is testing that the header Content-Type
is present in the response,
and its value must be exactly text/html;charset=UTF-8
.
In the implicit assert, quotes in the header value are part of the value itself.
Finally, we want to check that our server is creating a new session.
When creating a new session, our Spring Boot application should return a Set-Cookie
HTTP response header.
So to test it, we can modify our Hurl file with another header assert.
- Add a header assert on
Set-Cookie
header:
# Checking our home page:
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
xpath "//button" count == 2
xpath "string((//button)[1])" contains "Play"
xpath "string((//button)[2])" contains "Create"
# Testing HTTP response headers:
header "Content-Type" == "text/html;charset=UTF-8"
header "Set-Cookie" startsWith "JSESSIONID="
For Set-Cookie
header, we can use the specialized Cookie assert.
Not only we'll be able to easily tests cookie attributes (like HttpOnly
, or SameSite
), but also
it simplifies tests on cookies, particularly when there are multiple Set-Cookie
header in the HTTP response.
Hurl is not a browser, one can see it as syntactic sugar over curl. Hurl has no Javascript runtime and stays close to the HTTP layer. With others tools relying on headless browser, it can be difficult to access some HTTP requests attributes, like
Set-Cookie
header.
So to test that our server is responding a HttpOnly
session cookie, we can modify our file and add cookie asserts.
- Add two cookie asserts on the cookie
JESSIONID
:
# Checking our home page:
GET http://localhost:8080
HTTP/1.1 200
[Asserts]
xpath "string(//head/title)" == "Welcome to Quiz!"
xpath "//button" count == 2
xpath "string((//button)[1])" contains "Play"
xpath "string((//button)[2])" contains "Create"
# Testing content type:
header "Content-Type" == "text/html;charset=UTF-8"
# Testing session cookie:
cookie "JSESSIONID" exists
cookie "JSESSIONID[HttpOnly]" exists
- Run
basic.hurl
and check that every assert has been successful:
$ hurl basic.hurl
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Welcome to Quiz!</title>
<!-- <link rel="stylesheet" href="style.css">
<script src="script.js"></script>-->
</head>
....
</html>
Performance Test
TODO: add duration assert
Recap
Our Hurl file is now around 10 lines long, but we're already testing a lot on our home page:
- we are testing that our home page is responding with a
200 OK
- we are checking the basic structure of our page: a title, 2 buttons
- we are checking that the content type is UTF-8 HTML
- we are checking that our server has created a session, and that the cookie session has the
HttpOnly
attribute
You can see now that launching and running requests with Hurl is fast, really fast.
In the next session, we're going to see how we chain request tests, and how we add basic check on a REST api.