Code Conventions

All code complies with PSR-12 and PER Coding Style. The rules below are project-specific conventions that go beyond these standards -- this is what matters here.

Control Structure Spacing

IMPORTANT: Always add blank lines before and after control structures (foreach, for, while, if, switch) when they are not at the start or end of a block.

This rule is not in PSR-12/PER (which only states blank lines "MAY be added"). In this project, they are required.

Exception: No blank line needed when the control structure is at the start or end of a method/block.

When applying spacing rules around control structures, read references/code-examples.md for complete foreach, if, and exception examples.

Early Return Pattern

Always use early return to handle edge cases and invalid conditions first. This reduces nesting and improves readability.

• Reduces indentation: Main logic stays at base level
• Clarifies intent: Edge cases are handled first
• Blank line before return: When return is preceded by other statements in a block, add a blank line

When refactoring nested conditions to early returns, read references/code-examples.md for before/after examples and blank line rules.

If Continue Pattern in Loops

continue in a loop is the equivalent of early return in a function. Use continue only when the exit condition is simple and the main processing is more complex.

When both branches have comparable complexity, prefer a classic if/else for readability.

Note: Add a blank line before continue (and return, break, throw) when preceded by other statements in the block.

When deciding between continue and if/else in loops, read references/code-examples.md for side-by-side comparisons.

Nullsafe Operator to Flatten Nested Ifs

Use the nullsafe operator ?-> to avoid nested null checks.

When using match with nullable input, add null as a case.

When flattening nested null checks, read references/code-examples.md for nullsafe operator and match patterns.

Avoid empty() Function

NEVER use the empty() function. Use explicit comparisons instead.

The empty() function has unpredictable behavior with different types and hides potential bugs.

Type	Correct	Avoid
Arrays	$array === []	empty($array)
Strings	$string === ''	empty($string)
Null	$value === null	empty($value)

Parameter Ordering

In constructors, mandatory parameters come first, then optional ones. Within each group, promoted properties come before simple parameters:

1. Promoted mandatory (public/private/protected, required)
2. Simple mandatory (non-promoted, required)
3. Promoted optional (public/private/protected, nullable)
4. Simple optional (non-promoted, nullable)

When ordering constructor parameters, read references/code-examples.md for correct and incorrect examples.

Heredoc and Nowdoc (PER Coding Style Section 10)

Reference: PER Coding Style - Section 10

A nowdoc SHOULD be used wherever possible. Heredoc MAY be used only when a nowdoc does not satisfy requirements.

Indentation rules:

1. Declaration begins on the same line as its context
2. Content is indented once past the scope indentation
3. Closing identifier is at the same indentation level as the content

When writing heredoc/nowdoc blocks, read references/code-examples.md for PER-compliant and non-compliant examples.

Quick Reference

Rule	Example
Early return	if (invalid) { return; } then main logic
If continue in loops	Only when simple condition vs complex main logic
If/else in loops	When both branches have comparable complexity
Blank line before flow control	$x = 1; then blank then return; / continue; / break;
Blank line before control structure	$x = 1; then blank then foreach (...)
Blank line after control structure	} then blank then $y = 2;
Exception: start of block	No blank line needed
Exception: end of block	No blank line needed
Nullsafe for nested null checks	$a?->b?->c instead of nested if
No empty() function	$array === [] instead of empty($array)
Prefer nowdoc	<<<'SQL' instead of <<<SQL
Heredoc/nowdoc indentation	Content +1 level, closing same as content