DenverCoder1/github-readme-streak-stats · warning · InvalidArgumentException

400

400

Error message

GitHub username is required.

What it means

generateStreakStats() requires a GitHub username. After stripping all characters except alphanumerics and hyphens, an empty string means no usable username was supplied, so it throws InvalidArgumentException with code 400.

Solutions

1. Pass a non-empty GitHub username as the $user argument
2. Validate the username client-side before calling
3. Ensure the query parameter name is correct so the value isn't empty
4. Use only characters valid for GitHub usernames (letters, digits, hyphens)

Example fix

// before
generateStreakStats($_GET["user"] ?? "");
// after
$user = $_GET["user"] ?? "";
if ($user === "") { http_response_code(400); exit("user required"); }
generateStreakStats($user);

if (!is_string($user) || preg_match('/^[a-zA-Z0-9-]{1,39}$/', $user) !== 1) { throw new InvalidArgumentException("username required"); }

function isValidGitHubUsername($u): bool { return is_string($u) && preg_match('/^[a-zA-Z0-9-]{1,39}$/', $u) === 1; }

try { $stats = generateStreakStats($user); } catch (InvalidArgumentException $e) { if ($e->getCode() === 400) { http_response_code(400); echo "Username is required"; } }

When it happens

Trigger: Calling generateStreakStats('', ...) or passing a user value made entirely of characters that get stripped (e.g. symbols or spaces).

Common situations: Missing 'user' query parameter in an HTTP integration; a client sending whitespace-only or encoded-special-character usernames.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• Invalid color: " . $color
• 500
• 500
• 400
• 204

AI-assisted analysis of DenverCoder1/github-readme-streak-stats@70dd50f921 (2026-09-15). Data as JSON: /api/errors/9063a6f5e2152f63. Report an issue: GitHub.

Appendix: source

Thrown at src/generator.php:16

<?php

declare(strict_types=1);

/**
 * Generate streak stats for a GitHub user from request-style parameters.
 *
 * @param string $user GitHub username to get stats for
 * @param array<string,mixed> $params Options that affect fetching and streak calculation
 * @return array<string,mixed> The calculated streak stats
 */
function generateStreakStats(string $user, array $params = []): array
{
    $user = preg_replace("/[^a-zA-Z0-9\-]/", "", $user);
    if ($user === "") {
        throw new InvalidArgumentException("GitHub username is required.", 400);
    }

    $startingYear = isset($params["starting_year"]) ? intval($params["starting_year"]) : null;
    $mode = isset($params["mode"]) ? strval($params["mode"]) : null;
    $excludeDaysRaw = isset($params["exclude_days"]) ? strval($params["exclude_days"]) : "";
    $timezone = isset($params["timezone"]) ? strval($params["timezone"]) : "";

    // Build cache options based on request parameters
    $cacheOptions = [
        "starting_year" => $startingYear,
        "mode" => $mode,
        "exclude_days" => $excludeDaysRaw,
        "timezone" => $timezone,
    ];

    // Check if cache is disabled
    $useCache = !isset($_SERVER["DISABLE_CACHE"]) || strtolower(strval($_SERVER["DISABLE_CACHE"])) !== "true";

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