indent detector

indent-detector.php

#!/usr/bin/env php
<?php

declare(strict_types=1);

const INDENT_CHAR = ' ';
const INDENT_SIZE = 4;
const END_OF_LINE = "\n";

function exitWith(int $exitStatus, string $message): void
{
    error_log($message);
    exit($exitStatus);
}

function detect(string $filePath): void
{
    $contents = file_get_contents($filePath);
    if ($contents === false) {
        exitWith(10, sprintf('File not found: %s', $filePath));
    }

    $previousIndent = 0;
    foreach (explode(END_OF_LINE, $contents) as $lineNumber => $line) {
        $indent = strspn($line, INDENT_CHAR);

        // DocBlock
        if ($indent === $previousIndent + 1 && substr($line, $indent, 1) === '*') {
            $indent -= 1;
        }

        // DBG printf("%d: (%d) %d\n", $lineNumber, $previousIndent, $indent);

        if ($lineNumber === 0 && $indent !== 0) {
            exitWith(11, sprintf('First line indented in %s:%d', $filePath, $lineNumber + 1));
        }

        if ($indent < $previousIndent && $indent % INDENT_SIZE !== 0) {
            exitWith(12, sprintf('Indentation is smaller in %s:%d', $filePath, $lineNumber + 1));
        }

        if ($indent > $previousIndent && $indent !== $previousIndent + INDENT_SIZE) {
            exitWith(13, sprintf('Indentation does not match in %s:%d', $filePath, $lineNumber + 1));
        }

        if ($line !== '') {
            $previousIndent = $indent;
        }
    }
}

detect($argv[1]);