Fix response header parsing and content-type detection

[byjg]

Fixed critical bugs in AbstractRequester response handling:

1. Fixed header value extraction - PSR-7 headers are arrays, now properly extracts first element
2. Fixed content-type parsing to handle parameters (e.g., "application/json; charset=utf-8")
3. Restored JSON-by-default parsing for backwards compatibility
4. Added support for both text/xml and application/xml content types

This fixes all 17 test failures that were occurring due to response bodies being passed as strings instead of parsed arrays.

Tests: All 112 tests now passing (was 95/112)

[korbit-ai]

I was unable to write a description for this pull request. This could be because I only found files I can't scan.

[korbit-ai]

I was unable to write a description for this pull request. This could be because I only found files I can't scan.

[korbit-ai]

Review by Korbit AI

Korbit automatically attempts to detect when you fix issues in new commits.

Category	Issue	Status
	JSON Default Behavior Context Missing ▹ view
	Response Parser Logic Should Be Extracted ▹ view
	Inadequate JSON parsing error detection ▹ view
	JSON null responses incorrectly treated as parsing failures ▹ view
	Content-Type Split Rationale Missing ▹ view

Files scanned

​

File Path	Reviewed
src/AbstractRequester.php	✅

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[korbit-ai]

JSON Default Behavior Context Missing

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What is the issue?

The comment mentions backwards compatibility but doesn't explain the historical context or why this default is important.

Why this matters

Without understanding the historical context, developers might change this default behavior, breaking existing integrations.

Suggested change ∙ Feature Preview

    // Legacy APIs often return JSON without setting content-type. We default to JSON parsing
    // to maintain compatibility with these APIs and our pre-v1.0 behavior where we assumed JSON
    $responseBodyParsed = json_decode($responseBodyStr, true);

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[korbit-ai]

Response Parser Logic Should Be Extracted

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What is the issue?

Response body parsing logic is embedded within the send() method, violating Single Responsibility Principle and making the code harder to maintain and extend for new content types.

Why this matters

This tightly coupled design makes it difficult to add support for new content types and complicates testing. It also increases the cognitive complexity of the send() method.

Suggested change ∙ Feature Preview

Create a dedicated ResponseParser class or service:

class ResponseParser {
    public function parse(string $body, string $contentType): mixed {
        $mainContentType = $this->extractMainContentType($contentType);
        return match($mainContentType) {
            'text/xml', 'application/xml' => $this->parseXml($body),
            'application/json', '' => $this->parseJson($body),
            default => $this->parseDefault($body)
        };
    }
}

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[korbit-ai]

JSON null responses incorrectly treated as parsing failures

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What is the issue?

The JSON parsing fallback logic incorrectly treats valid JSON null responses as parsing failures, causing them to be returned as raw strings instead of null values.

Why this matters

When an API legitimately returns JSON null (which is valid JSON), json_decode() returns PHP null, but the condition treats this as a parsing failure. This breaks APIs that intentionally return null values and violates the principle of least surprise for JSON API consumers.

Suggested change ∙ Feature Preview

Use json_last_error() to properly detect JSON parsing failures instead of checking for null return value:

// Default to JSON parsing (for backwards compatibility and when content-type is not set)
$responseBodyParsed = json_decode($responseBodyStr, true);
// If JSON parsing fails and content-type is explicitly not JSON, use raw string
if (json_last_error() !== JSON_ERROR_NONE && $mainContentType !== '' && $mainContentType !== 'application/json') {
    $responseBodyParsed = $responseBodyStr;
}

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[korbit-ai]

Content-Type Split Rationale Missing

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What is the issue?

The comment only describes what the code does, not why this handling is necessary.

Why this matters

Without understanding why content type needs to be split, future developers might remove this code thinking it's unnecessary, leading to content type parsing issues.

Suggested change ∙ Feature Preview

    // Content-Type headers may include parameters (e.g., charset) that interfere with type matching.
    // Extract only the MIME type portion for accurate content type comparison
    $mainContentType = explode(';', $contentType)[0];
    $mainContentType = trim($mainContentType);

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[korbit-ai]

Inadequate JSON parsing error detection

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What is the issue?

JSON parsing errors are only partially handled by checking for null return value, but json_decode can return null for valid JSON (null value) and doesn't distinguish between parsing errors and valid null responses.

Why this matters

This approach cannot differentiate between a valid JSON null response and a JSON parsing error, potentially masking actual parsing failures and leading to incorrect fallback behavior.

Suggested change ∙ Feature Preview

Use json_last_error() to properly detect JSON parsing errors:

$responseBodyParsed = json_decode($responseBodyStr, true);
// Check for JSON parsing errors, not just null return value
if (json_last_error() !== JSON_ERROR_NONE && $mainContentType !== '' && $mainContentType !== 'application/json') {
    $responseBodyParsed = $responseBodyStr;
}

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