rspec-oj
Easily handle JSON in RSpec and Cucumber
RSpec
rspec-oj defines five new RSpec matchers:
be_json_eql
include_json
have_json_path
have_json_type
have_json_size
The new matchers could be used in RSpec as follows:
describe User do
let(:user){ User.create!(first_name: "Steve", last_name: "Richert") }
context "#to_json" do
it "includes names" do
names = { "first_name": "Steve", "last_name": "Richert" }
expect(user).to be_json_eql(names).excluding("friends")
end
it "includes the ID" do
expect(user).to have_json_path("id")
expect(user).to have_json_type(Integer).at_path("id")
end
it "includes friends" do
expect(user).to have_json_size(0).at_path("friends")
friend = User.create!(first_name: "Catie", last_name: "Richert")
user.friends << friend
expect(user).to have_json_size(1).at_path("friends")
expect(user).to include_json(friend)
end
end
end
rspec-oj also provides some useful helpers for RSpec tests:
parse_json
normalize_json
generate_normalized_json
load_json
To start using them add an include them in your RSpec configuration:
RSpec.configure do |config|
config.include RSpec::Oj::Helpers
end
You can find usage examples for the helpers in spec/rspec/oj/helpers_spec.rb
Exclusions
rspec-oj ignores certain hash keys by default when comparing JSON:
id
created_at
updated_at
It's oftentimes helpful when evaluating JSON representations of newly-created ActiveRecord records so that the new ID and timestamps don't have to be known. These exclusions are globally customizeable:
RSpec::Oj.configure do
exclude_keys "created_at", "updated_at"
end
Now, the id
key will be included in rspec-oj's comparisons. Keys can also be excluded/included
per matcher by chaining the excluding
or including
methods (as shown above) which will add or
subtract from the globally excluded keys, respectively.
Paths
Each of rspec-oj's matchers deal with JSON "paths." These are simple strings of "/" separated hash keys and array indexes. For instance, with the following JSON:
{
"first_name": "Steve",
"last_name": "Richert",
"friends": [
{
"first_name": "Catie",
"last_name": "Richert"
}
]
}
We could access the first friend's first name with the path "friends/0/first_name"
.
Cucumber
rspec-oj provides Cucumber steps that utilize its RSpec matchers and that's where rspec-oj really shines. This is perfect for testing your app's JSON API.
In order to use the Cucumber steps, in your env.rb
you must:
require "rspec/oj/cucumber"
You also need to define a last_json
method. If you're using Capybara, it could be as simple as:
def last_json
page.source
end
Now, you can use the rspec-oj steps in your features:
Feature: User API
Background:
Given the following users exist:
| id | first_name | last_name |
| 1 | Steve | Richert |
| 2 | Catie | Richert |
And "Steve Richert" is friends with "Catie Richert"
Scenario: Index action
When I visit "/users.json"
Then the JSON response should have 2 users
And the JSON response at "0/id" should be 1
And the JSON response at "1/id" should be 2
Scenario: Show action
When I visit "/users/1.json"
Then the JSON response at "first_name" should be "Steve"
And the JSON response at "last_name" should be "Richert"
And the JSON response should have "created_at"
And the JSON response at "created_at" should be a string
And the JSON response at "friends" should be:
"""
[
{
"id": 2,
"first_name": "Catie",
"last_name": "Richert"
}
]
"""
The background steps above aren't provided by rspec-oj and the "visit" steps are provided by Capybara. The remaining steps, rspec-oj provides. They're versatile and can be used in plenty of different formats:
Then the JSON should be:
"""
{
"key": "value"
}
"""
Then the JSON at "path" should be:
"""
[
"entry",
"entry"
]
"""
Then the JSON should be {"key":"value"}
Then the JSON at "path" should be {"key":"value"}
Then the JSON should be ["entry","entry"]
Then the JSON at "path" should be ["entry","entry"]
Then the JSON at "path" should be "string"
Then the JSON at "path" should be 10
Then the JSON at "path" should be 10.0
Then the JSON at "path" should be 1e+1
Then the JSON at "path" should be true
Then the JSON at "path" should be false
Then the JSON at "path" should be null
Then the JSON should include:
"""
{
"key": "value"
}
"""
Then the JSON at "path" should include:
"""
[
"entry",
"entry"
]
"""
Then the JSON should include {"key":"value"}
Then the JSON at "path" should include {"key":"value"}
Then the JSON should include ["entry","entry"]
Then the JSON at "path" should include ["entry","entry"]
Then the JSON should include "string"
Then the JSON at "path" should include "string"
Then the JSON should include 10
Then the JSON at "path" should include 10
Then the JSON should include 10.0
Then the JSON at "path" should include 10.0
Then the JSON should include 1e+1
Then the JSON at "path" should include 1e+1
Then the JSON should include true
Then the JSON at "path" should include true
Then the JSON should include false
Then the JSON at "path" should include false
Then the JSON should include null
Then the JSON at "path" should include null
Then the JSON should have "path"
Then the JSON should be a hash
Then the JSON at "path" should be an array
Then the JSON at "path" should be a float
Then the JSON should have 1 entry
Then the JSON at "path" should have 2 entries
Then the JSON should have 3 keys
Then the JSON should have 4 whatevers
All instances of "should" above could be followed by "not" and all instances of "JSON" could be downcased and/or followed by "response."
Table Format
Another step exists that uses Cucumber's table formatting and wraps two of the above steps:
Then the JSON should have the following:
| path/0 | {"key":"value"} |
| path/1 | ["entry","entry"] |
Any number of rows can be given. The step above is equivalent to:
Then the JSON at "path/0" should be {"key":"value"}
And the JSON at "path/1" should be ["entry","entry"]
If only one column is given:
Then the JSON should have the following:
| path/0 |
| path/1 |
This is equivalent to:
Then the JSON should have "path/0"
And the JSON should have "path/1"
JSON Memory
There's one more Cucumber step that rspec-oj provides which hasn't been used above. It's used to memorize JSON for reuse in later steps. You can "keep" all or a portion of the JSON by giving a name by which to remember it.
Feature: User API
Scenario: Index action includes full user JSON
Given the following user exists:
| id | first_name | last_name |
| 1 | Steve | Richert |
And I visit "/users/1.json"
And I keep the JSON response as "USER_1"
When I visit "/users.json"
Then the JSON response should be:
"""
[
%{USER_1}
]
"""
You can memorize JSON at a path:
Given I keep the JSON response at "first_name" as "FIRST_NAME"
You can remember JSON at a path:
Then the JSON response at "0/first_name" should be:
"""
%{FIRST_NAME}
"""
You can also remember JSON inline:
Then the JSON response at "0/first_name" should be %{FIRST_NAME}
More
Check out the specs and features to see all the various ways you can use rspec-oj.
Contributing
If you come across any issues, please tell us. Pull requests (with tests) are appreciated. No pull request is too small. Please help with:
- Reporting bugs
- Suggesting features
- Writing or improving documentation
- Fixing typos
- Cleaning whitespace
- Refactoring code
- Adding tests
- Closing issues
If you report a bug and don't include a fix, please include a failing test.
Copyright
Copyright © 2020 Steve Richert
See LICENSE for details.