perldoc > Test::Unit::Assertion

Che Dong

📛 NAME

Test::Unit::Assertion — The abstract base class for assertions

🚀 Quick Reference

Use Case	Command	Description
📝 Create a custom assertion subclass	`package MyAssertion; use base 'Test::Unit::Assertion';`	Define a new assertion class that inherits from the abstract base
🛠️ Implement the assertion logic	`sub do_assertion { ... return 1 if success; }`	Override `do_assertion` to return true on success, false or throw on failure
🔗 Use with Test::Unit::Assert	`Test::Unit::Assert::assert( MyAssertion->new(...) )`	Pass an assertion object to `assert`; it calls `do_assertion`

📛 NAME

Any assertion class that expects to plug into Test::Unit::Assert needs to implement this interface.

📋 Required methods

new 🆕 Creates a new assertion object. Takes whatever arguments you desire. Isn't strictly necessary for the framework to work with this class but is generally considered a good idea.
do_assertion ⚙️ This is the important one. If Test::Unit::Assert::assert is called with an object as its first argument then it does:
```
$_[0]->do_assertion(@_[1 .. $#_]) ||
    $self->fail("Assertion failed");
```
This means that do_assertion should return true if the assertion succeeds and false if it doesn't. Or, you can fail by throwing a Test::Unit::Failure object, which will get caught further up the stack and used to produce a sensible error report. Generally it's good practice for do_assertion to die with a meaningful error on assertion failure rather than just returning false.

✍️ AUTHOR

📚 SEE ALSO

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