Approval Tests are an alternative to assertions. You’ll find them useful for testing objects with complex values (such as long strings), lots of properties, or collections of objects.
Approval tests
simplify this by taking a snapshot of the results, and confirming that they have not changed.
In normal unit testing, you say expect(person.getAge(), 5)
. Approvals allow you to do this when the thing that you want to assert is no longer a primitive but a complex object. For example, you can say, Approvals.verify(person)
.
I am writing an implementation of Approval Tests in Dart. If anyone wants to help, please text me. 🙏
Add the following to your pubspec.yaml
file:
dependencies:
approval_tests: ^0.4.5
Approving results just means saving the .approved.txt
file with your desired results.
We’ll provide more explanation in due course, but, briefly, here are the most common approaches to do this.
Most diff tools have the ability to move text from left to right, and save the result.
How to use diff tools is just below, there is a Comparator
class for that.
If you want the result to be automatically saved after running the test, you need to use the approveResult
property in Options
:
test('test complex JSON object', () {
var complexObject = {
'name': 'JsonTest',
'features': ['Testing', 'JSON'],
'version': 0.1,
};
ApprovalTests.verifyAsJson(
complexObject,
options: const Options(
approveResult: true,
),
);
});
You can just rename the .received
file to .approved
.
You can use different comparators to compare files. The default is CommandLineComparator
which compares files in the console.
To use IDEComparator
you just need to add it to options
:
options: const Options(
comparator: IDEComparator(
ide: ComparatorIDE.visualStudioCode,
),
),
But before you add an IDEComparator
you need to do the initial customization:
-
Visual Studio Code
- For this method to work, you need to have Visual Studio Code installed on your machine.
- And you need to have the
code
command available in your terminal. - To enable the
code
command, pressCmd + Shift + P
and typeShell Command: Install 'code' command in PATH
.
-
IntelliJ IDEA
- For this method to work, you need to have IntelliJ IDEA installed on your machine.
- And you need to have the
idea
command available in your terminal. - To enable the
idea
command, you need to create the command-line launcher usingTools - Create Command-line Launcher
in IntelliJ IDEA.
-
Android Studio
- For this method to work, you need to have Android Studio installed on your machine.
- And you need to have the
studio
command available in your terminal. - To enable the
studio
command, you need to create the command-line launcher usingTools - Create Command-line Launcher
in Android Studio.
I have provided a couple of small examples here to show you how to use the package.
There are more examples in the example
folder for you to explore. I will add more examples in the future.
Inside, in the gilded_rose
folder, there is an example of using ApprovalTests
to test the legacy code of Gilded Rose kata.
You can study it to understand how to use the package to test complex code.
And the verify_methods
folder has small examples of using different ApprovalTests
methods for different cases.
You must add any approved
files to your source control system. But received
files can change with any run and should be ignored. For Git, add this to your .gitignore
:
*.received.*
Ask me on Telegram: @yelmuratoff
.
Email: [email protected]
- Getting Started with ApprovalTests.Swift
- How to Verify Objects (and Simplify TDD)
- Verify Arrays and See Simple, Clear Diffs
- Write Parameterized Tests by Transforming Sequences
- Wrangle Legacy Code with Combination Approvals
You can also watch a series of short videos about using ApprovalTests in .Net on YouTube.
Prefer learning by listening? Then you might enjoy the following podcasts:
Show some 💙 and star the repo to support the project! 🙌
The project is in the process of development and we invite you to contribute through pull requests and issue submissions. 👍
We appreciate your support. 🫰