UnitEnumJsonEncoding

error native on by default PHP ≥ 8.1

Group: Probable bugs

Detect json_encode receiving a resolved unit enum value without a JsonSerializable implementation.

Example

<?php
enum Mode {case Quick;} echo json_encode(Mode::Quick);

Reported:

• line 2: Serialize this unit enum through an explicit representation.

Detection

• Report json_encode receiving a resolved unit enum value without a JsonSerializable implementation.
• Resolve builtin calls and named arguments before checking the contract. Project-local callees are considered only when their bodies or immutable summaries establish the required facts. The default is enabled, with positive proof required.
• For flow-dependent conditions, require a reachable source-to-use path with no intervening invalidation. Unknown calls, ambiguous aliases, recursion or analysis-budget exhaustion cannot establish definite facts.

Exceptions (no report)

• Backed enums, custom serializers, explicit name projection and unknown values are excluded.
• Unresolved targets, incomplete required facts, suppressed findings and PHP versions lacking the referenced API or language feature produce no report. User declarations shadowing builtin names are not builtin contracts.

Fix

No automatic fix: serializing a name rather than rejecting the value changes the public data contract.

PHP versions

Available from PHP 8.1. Builtin behavior and argument contracts follow the configured PHP version. Extension-specific calls require resolved extension API symbols; do not treat same-named application functions as extension calls.

Options

None. Enable or disable this rule through normal rule configuration.

Configure

In custos.json:

{
  "rules": {
    "UnitEnumJsonEncoding": {
      "enabled": false
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file):

// @custos-ignore UnitEnumJsonEncoding