Fix batch response decoding when regex finds no JSON match

[Copilot]

SAP SuccessFactors batch responses contain multipart MIME content that causes ODataResponse::decodeBody() to crash with "Undefined array key 0" error. The method attempts to extract JSON via regex, but unconditionally accesses $matches[0] even when no match is found.

Changes

src/ODataResponse.php

• Guard $matches[0] access with conditional check on preg_match() return value
• Falls through to empty array when no JSON found in response body

tests/BatchResponseTest.php

• Add test coverage for batch responses with multipart MIME content
• Add test coverage for responses without JSON content
• Add regression tests for normal JSON and embedded JSON responses

Example

Before:

preg_match('~\{(?:[^{}]|(?R))*\}~', $this->body, $matches);
$decodedBody = json_decode($matches[0], true, 512, JSON_BIGINT_AS_STRING);
// Crashes if $matches is empty

After:

if (preg_match('~\{(?:[^{}]|(?R))*\}~', $this->body, $matches)) {
    $decodedBody = json_decode($matches[0], true, 512, JSON_BIGINT_AS_STRING);
}
// Returns empty array if no match found

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/CarbonPHP/carbon-doctrine-types/zipball/18ba5ddfec8976260ead6e866180bd5d2f71aa1d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/CarbonPHP/carbon/zipball/8e3643dcd149ae0fe1d2ff4f2c8e4bbfad7c165f
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/doctrine/inflector/zipball/6d6c96277ea252fc1304627204c3d5e6e15faa3b
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/guzzle/guzzle/zipball/b51ac707cfa420b7bfd4e4d5e510ba8008e822b4
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/guzzle/promises/zipball/481557b130ef3790cf82b713667b43030dc9c957
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/guzzle/psr7/zipball/21dc724a0583619cd1652f673303492272778051
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/illuminate/collections/zipball/deb291b109b6f7fd776a3550a120771137b3c5d1
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/illuminate/conditionable/zipball/ec677967c1f2faf90b8428919124d2184a4c9b49
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/illuminate/contracts/zipball/5ab717c8f0dd4e84be703796bbb415ccff8de57a
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/illuminate/macroable/zipball/e862e5648ee34004fa56046b746f490dfa86c613
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/illuminate/support/zipball/d9780f626aa79d6b7b9c18f0d886340a29c66659
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/php-fig/clock/zipball/e41a24703d4560fd0acb709162f73b8adfc3aa0d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/php-fig/container/zipball/c71ecc56dfe541dbd90c5360474fbc405f8d5963
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/php-fig/http-client/zipball/bb5906edc1c324c9a05aa0873d40117941e5fa90
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/php-fig/http-factory/zipball/2b4765fddfe3b508ac62f829e852b1501d3f6e8a
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/php-fig/http-message/zipball/402d35bcb92c70c026d1a6a9883f06b2ead23d71
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/php-fig/simple-cache/zipball/764e0b3939f5ca87cb904f570ef9be2d78a07865
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/phpstan/phpstan/zipball/e126cad1e30a99b137b8ed75a85a676450ebb227
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/ralouphie/getallheaders/zipball/120b605dfeb996808c31b6477290a714d356e822
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/type/zipball/e549163b9760b8f71f191651d22acf32d56d6d4d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/sebastianbergmann/version/zipball/3e6ccf7657d4f0a59200564b08cead899313b53c
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/staabm/side-effects-detector/zipball/d8334211a140ce329c13726d4a715adbddd0a163
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/HVo7xK /usr/bin/composer install --no-interaction (http block)
• https://api.github.com/repos/symfony/clock/zipball/b81435fbd6648ea425d1ee96a2d8e68f4ceacd24
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/deprecation-contracts/zipball/63afe740e99a13ba87ec199bb07bbdee937a5b62
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/polyfill-mbstring/zipball/6d857f4d76bd4b343eac26d6b539585d2bc56493
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/polyfill-php83/zipball/17f6f9a6b1735c0f163024d959f700cfbc5155e5
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/polyfill-php84/zipball/d8ced4d875142b6a7426000426b8abc631d6b191
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/polyfill-php85/zipball/d4e5fcd4ab3d998ab16c0db48e6cbb9a01993f91
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/translation-contracts/zipball/65a8bc82080447fae78373aa10f8d13b38338977
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/symfony/translation/zipball/ec25870502d0c7072d086e8ffba1420c85965174
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)
• https://api.github.com/repos/voku/portable-ascii/zipball/b1d923f88091c6bf09699efcd7c8a1b1bfd7351d
  • Triggering command: /usr/bin/php8.3 -n -c /tmp/R0WEXV /usr/bin/composer install --no-dev --no-interaction (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Batch requests failed decoding body</issue_title>
<issue_description>Hello,

I've been using your library since last year to handle OData requests, thanks for your work, it really helped a lot.

When using $client->batch() against SAP SuccessFactors OData v2, the client throws an ODataException during decodeBody().

Here an example of a simple query made to SuccessFactors with the library :

$batch = $client->batch();

$batch->get("EmpJob?\$top=5&\$format=json", 'get-empjob');
$response = $batch->execute();

After debugging, we got the response, and the decode part fails, with this error : The HTTP client sent back an invalid response.

Here is the response (redacted for privacy reasons) :

--batch_f20d8021-677a-4f93-8e62-862b6f383d15
Content-Type: application/http
Content-Transfer-Encoding: binary

HTTP/1.1 200 OK
Content-Type: application/json;charset=utf-8
DataServiceVersion: 2.0
Record-Count: 5
X-SF-Record-Count-Recursive: 5
successfactors-message: X-SF-Correlation-Id, successfactors-sourcetype are missing in request headers
Content-Length: 76038

{
"d" : {
"results" : [REDACTED]
}
}

--batch_f20d8021-677a-4f93-8e62-862b6f383d15--

What happened is in the decodeBody() function in ODataResponse :

    private function decodeBody()
    {
        $decodedBody = json_decode($this->body, true, 512, JSON_BIGINT_AS_STRING);
        if ($decodedBody === null) {
            $matches = null;
            preg_match('~\{(?:[^{}]|(?R))*\}~', $this->body, $matches);
            $decodedBody = json_decode($matches[0], true, 512, JSON_BIGINT_AS_STRING);
            if ($decodedBody === null) {
                $decodedBody = array();
            }
        }
        return $decodedBody;
    }

First try fail, because the body isnt a full JSON, then the preg_match doesnt match anything, so when trying to decode $matches[0], we got an ErrorException because of "Undefined array key 0", so ODataRequest throw the ODataException with the UNABLE_TO_PARSE_RESPONSE constant.

I'm quite not sure why since I'm not really an OData expert, I'm willing to help as far as I can.

Thanks for your help and for your really good lib !

Have a nice day.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Batch requests failed decoding body #192

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.