HERE'S WHAT A GOOD DEVELOPER NEEDS TO KNOW...

Creating classes - Class properties - Class methods - Method arguments - Named arguments - Constructors - Constructor promoted properties - Type hinting - Class type declarations - Return type declarations - Inheritance - Redundancy and duplication - The 'extends' keyword - Inheritance and constructors - Overriding parent methods - Visibility - Protected properties - Private properties - Method visibility - Encapsulation - Typed properties - Union types - Static properties - Static methods - Class constants - Abstract classes - Abstract methods - Interfaces - Traits - Combining traits and interfaces - Traits and precedence - Abstract methods in traits - Static methods in traits - Late static binding - The 'final' keyword - Exceptions - Try / catch blocks - Exception subclasses - Custom Exceptions - finally blocks - Error class - get magic method - set magic method - unset magic method - toString magic method - destruct magic method - call magic method - clone magic method - invoke magic method - Namespaces - Organizing using namespaces - Autoloading - Autoloading namespaced classes - Autoloading with composer - Inspecting classes - Inspecting class attributes - Reflection API: ReflectionClass - Reflection API: ReflectionMethod - Single Responsibility Principle - Composition - Dependency Injection - Polymorphism - Callables Part One - Callables Part Two - Anonymous Classes -Creating a MySQL Database - The Singleton Pattern - PHP Data Objects (PDO) - PDO Queries - Object Relational Mapping - Creating ORM Entity Classes - Generating Schema SQL - ORM Relationships - Serialization - Serializing Objects - Unserializing Objects - sleep Magic Method - wakeup Magic Method - serialize Magic Method - unserialize Magic Method - DateTime Class - Comparing Dates - Modifying Dates - Array Access - Iterator Interface - Countable Interface - IteratorAggregate - ArrayObject - Collection Classes - Composite pattern - Decorator - Adapter - Strategy - Observer - Null Object - Dependency Injection - Service Locator - Factory Method

Testing functions - Testing class methods - Filtering tests - Errors vs failures - The setUp method - The tearDown method - Using tests to refactor - Common assertions - Custom failure messages - Configuring PHPUnit - Testing errors and exceptions - Data providers - Testing strategies - Risky tests and incomplete tests - Mocking - Refactoring for easier testing - Mocking static methods - Testing all logic paths - Should you replace static methods? - Integration testing - When not to mock - Testing API integration - Grouping tests - Authentication exception testing - Testing against a database - Create a test database connection - Database refresh tool - Database dependant test cases - Testing ordered database records - Testing null database returns - Test saving to the database - Database test assertions - Feature test assertions - Running feature tests - PHPUnit Test Doubles - Testing expectations - Faking method return values - Testing consecutive returns - Throwing exceptions from stubbed methods - Will return callback - Test faked methods receive correct arguments - Test faked methods receive correct arguments using callbacks - The mock builder - Test coverage introduction - Test coverage setup - HTML Format coverage report - Maximising test coverage - Test Driven Development (TDD) - Using tests to switch libraries - Testing HTTP Request / Response - Asserting against response content - Testing authenticated endpoints

The Front Controller - Request Class - Response Class - Http Kernel - Routing - Adding Routes - Retrieving Path Info - Defining Routes - Controller Classes - Controller Method Arguments - Router Classes - Flexible Route Handling - Exception Handling - When to Fork a Repository - Create a Framework Repository - Create a Container - Container Exceptions - Container Has Checks - Autowiring - Using a Container - Container Aliases - Container Parameters - Resolving a Controller - Controller Autowiring - Environment Modes - Using Environment Variables - Templating - Twig Templating Engine - Abstract Controller - Rendering Templates - Creating View Templates - Reusable Templates - Input Forms - Preventing Cross-Site Scripting (XSS) Attacks - Database Abstraction Layer - Migration Files - Console Application Entrypoint - Command Classes - Registering Commands - Running a Console Application - Executing Console Commands - Command Options - Database Migration Steps - Creating Migrations Tables - Database Transactions - Obtaining Applied Migrations - Getting Migration Files To Apply - Migrating Up - Inserting Migrations - Executing Migrations Queries - Submitting a Form - Accessing the Request - Creating a Post Entity - Data Mapper - Repositories - Find or Fail Methods - Redirect Responses - Sessions and Flash Messages - Template Renderer Factory - Rendering Flash Messages - PSR-15 Middleware - Injecting Middleware - Resolving Middleware - Middleware Completion - Session Start Middleware - Request Clean Up - Auth User Entities - User Tables - Register Forms and Routing - Registration Handling - Registration Form - Validating Form Input - Redirecting with Errors - Completing Registration - Login Form and Routing - The Login Steps - Authentication / Security Component - Verifying User Credentials - Auth User Repository - Logging In a User - Redirecting an Authenticated User - Route Middleware - Injecting Middleware - Refactoring a Router - Authenticate Middleware - Guest Middleware - Completing Registration - Logout Links - Handling The Logout - Introduction - Event Dispatcher - Event Objects - Dispatching an Event - Event Listeners - Adding Event Listeners - Stopping Event Propagation - Amending Paths - Service Providers - Registering Service Providers

It should take years to piece together quality, up to date, learning resources that cover all this stuff...

...BUT it's all covered here IN GREAT DEPTH