PHPAML

Documentation · Chapter 19

Practice a repeatable diagnostic method.

This workshop diagnoses five controlled failures and records cause, correction, and regression check.

Every lesson starts from the problem, explains the mechanism, then gives a concrete verification.

LESSON OBJECTIVE

What you will be able to do

Solve controlled incidents with a repeatable decision tree and convert discoveries into prevention.

Create safe failures

In a disposable project, create an occupied port, missing runtime, unknown route, invalid database driver, and unsupported View closure.

phpaml — zsh
Failure log
- symptom and exact message
- responsible layer
- decisive evidence
- correction
- regression check

Apply the decision tree

For each, classify layer, gather one decisive proof, apply one correction, and rerun the original command before moving on.

Turn every real bug into prevention

Add a regression test, doctor rule, clearer exception, documentation note, or safer default. Troubleshooting improves the product when knowledge becomes automation.

CHECKPOINT

Before you continue

After the fix, what test, diagnostic rule, safer default, or documentation change prevents the same blind spot?

SUMMARY

What to remember

  • Preserve the first evidence before changing the system.
  • Identify the failing layer before choosing a repair.
  • Status codes, routes, logs, and doctor outputs narrow the cause.
  • Convert important bugs into tests, diagnostics, or safer defaults.