PHP: how to use assert [closed]

Question

In PHP, what are the best practices you following when using asserts? I'm curious about general use of asserts and PHP specific practices.

Answer 1

Design By Contract

I believe assert is not used much in PHP. You could use it if you Design By Contract.

Design by Contract (DbC) or Programming by Contract is an approach to designing computer software. It prescribes that software designers should define formal, precise and verifiable interface specifications for software components, which extend the ordinary definition of abstract data types with preconditions, postconditions and invariants. These specifications are referred to as "contracts", in accordance with a conceptual metaphor with the conditions and obligations of business contracts.

This tutorial explains it a little bit.

TDD / Unit Test

I would instead advise you to unit test your code(TDD) following these 3 simple rules(must read article).

1. You are not allowed to write any production code unless it is to make a failing unit test pass.
2. You are not allowed to write any more of a unit test than is sufficient to fail; and compilation failures are failures.
3. You are not allowed to write any more production code than is sufficient to pass the one failing unit test.

You must begin by writing a unit test for the functionality that you intend to write. But by rule 2, you can't write very much of that unit test. As soon as the unit test code fails to compile, or fails an assertion, you must stop and write production code. But by rule 3 you can only write the production code that makes the test compile or pass, and no more.

If you think about this you will realize that you simply cannot write very much code at all without compiling and executing something. Indeed, this is really the point.

To practice(discipline) this you should use the excellent PHPUnit framework. You should read this Writing Tests for PHPUnit to get a feeling for this discipline.