How to integrate testing into PHP development process?

Question

PHP

Good day to all.
My office is developing on yii symphony, quite a few jquery, etc.
Well and accordingly testing simply is not present. I'm tired of supporting projects for half a year and fixing my bugs, and I'm not satisfied with the customers. Projects are getting more complex, bigger and more expensive. You can no longer make raw products, you need to grow, and I decided that I should start testing my code.
Please tell me who was at such a stage in the development of the company, their own or in the one in which they worked.
How did you start testing the code, how were you able to sell it to customers, and how has your development process changed since testing was introduced?

Answer 1

I learned to write tests simply: when you deal with money, the price of a mistake is high. Without tests, writing processing is better to shoot yourself right away. I did not study on my own - that was the policy of the team leader.
When there is already a project with legacy code (and yours is exactly that, according to Bob Martin's definition), then the only way to start changing something is to start writing tests for new functionality. And if hands reach refactoring, then also immediately cover this code with tests.
As for customers, they really don't care if they have tests or not. Therefore, it is necessary to estimate the development time in such a way that it includes the time for writing tests. As experience shows, no one will ask the question "Why so long?". If asked, then you can answer by type "