CallbackRequiredArgumentMismatch

error native on by default

Group: Probable bugs

Detect array_map with N supplied input arrays and a resolved callback requiring more than N positional parameters.

Example

<?php
array_map(fn($value, $key) => $key . $value, $items);

function join_pair($left, $right) { return $left . $right; }
array_map('join_pair', $items);

// Not reported: which declaration runs depends on the branch taken.
if (PHP_VERSION_ID < 80000) {
    function label($item, $prefix) { return $prefix . $item; }
} else {
    function label($item) { return (string) $item; }
}
array_map('label', $items);

Reported:

• line 2: Match the callback parameters to the supplied arrays.
• line 5: Match the callback parameters to the supplied arrays.

Detection

• Report array_map with N supplied input arrays and a resolved callback requiring more than N positional parameters.
• 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 or recursion cannot establish definite facts. When the proof is inconclusive, nothing is reported.
• A string callback naming a project function is resolved only when that fully qualified function name has exactly one declaration in the index, and its body is a direct statement of the analyzed file or of a namespace. Such a declaration is the signature every call reaches.

Exceptions (no report)

• Optional parameters, variadics, unresolved callbacks, and array_map with null callback 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.
• A string callback whose function is declared inside a condition, loop, function body or any other nested statement, or its fully qualified name has multiple indexed declarations (for example one signature per if/else branch, or a function_exists guarded fallback), is unresolved: the signature bound at run time is not known, so nothing is reported.

Fix

No automatic fix: an additional input array cannot be invented.

PHP versions

Apply only on PHP versions supporting the referenced APIs and syntax (within PHP 5.3–8.5). 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": {
    "CallbackRequiredArgumentMismatch": {
      "enabled": false
    }
  }
}

Suppress

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

// @custos-ignore CallbackRequiredArgumentMismatch