MatchJSON

Test your JSON in RSpec, MiniTest or Cucumber, like a boss.

The only matcher I let my kids play with -- Mom

Getting Started

Ever since the dawn of mankind, humans everywhere have been searching for a tool to test their JSON.

Then computers were invented.

Then matchJSON came about.

Then everyone lived happily ever after.

Stop warping your brain with hard-to-read regex and weird-looking tests.

The old, yucky way:

it "returns the current pony" do
  get "/ponies/#{pony.id}"

  current_pony = JSON.parse(response.body)["pony"]
  expect(current_pony["cuteness"]).to eq 90
  expect(current_pony["fluffiness"]).to eq "extra-fluffy"
  expect(current_pony["name"]).to eq "McPony"
end

The new, cool way:

it "returns the current pony" do
  get "/ponies/#{pony.id}"

  expect(response).to match_json(<<-JSON)
  {
    "cuteness": 90,
    "fluffiness": "extra-fluffy",
    "name": "McPony",
  }
  JSON
end

Wait, you already use JSON-Schema? We're BFFs ❤️

it "returns the current pony" do
  get "/ponies/#{pony.id}"

  # JSON-Schema to check the schema
  expect(response).to match_response_schema(:pony)

  # MatchJSON to test the values (gotta love explicit tests)
  expect(response).to match_json(<<-JSON)
  {
    "cuteness": 90,
    "fluffiness": "extra-fluffy",
    "name": "McPony",
  }
  JSON
end

Installation

• Drop this baby into your Gemfile like so:

gem 'match_json'

• Run bundle

Rspec

In spec_helper.rb or rails_helper.rb include library as following:

require 'match_json/rspec'

In minitest's test_helper.rb add this:

require 'match_json/minitest'

Advanced usage

Patterns

Add some patterns in the mix to make things interesting:

# RSpec
it 'returns ponies' do
  get '/ponies/#{pony.id}'

  expect(response).to match_json(<<-JSON)
  {
    "id": "{uuid}", # UUID Pattern
    "cuteness": 90,
    "fluffiness": "extra-fluffy",
    "name": "McPony",
    "created_at": "{date_time_iso8601}" # DateTime pattern (well, duh)
  }
  JSON
end

Here's a list of the built-in patterns we provide:

• date_time_iso8601
• date
• uuid
• email
• string

Define your own patterns

Just add them to spec/support/match_json.rb:

MatchJson::Matchers::IncludeJson::PATTERNS['id'] = /\A\d{6}\z/
MatchJson::Matchers::IncludeJson::PATTERNS[/id:(\w+)'] = proc { |actual, match| /\A#{match}_\z/ =~ actual }

and then use it in your spec like so:

it 'uses patten to check value' do

  # MatchJson::Matchers::IncludeJson::PATTERNS['id'] = /\A\d{6}\z/
  expect(%Q({"one": "123456"})).to match_json(%Q({"one": "{id}"}))
  # .. you can even do this:
  expect(%Q({"one": 123456})).to match_json(%Q({"one": {id}}))

  # MatchJson::Matchers::IncludeJson::PATTERNS[/id:(\w+)'] = proc { |actual, match| /\A#{match}_\z/ =~ actual }
  expect(%Q({"id": "usr_xxx"})).to match_json(%Q({"one": "{id:usr}"}))
  expect(%Q({"id": "cus_xxx"})).to match_json(%Q({"one": "{id:cus}"}))
end

Contributing

1. Fork it ( https://github.com/[your-github-username]/match_json/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request