[quotentiroler]

💡 Motivation and Context

Local evaluation of regex and not_regex filters gave different answers from the flags service. The SDK treated the filter value as a PHP delimited pattern whenever it happened to compile as one, and otherwise wrapped it in / without escaping. As a result:

• ^https://example\.com/ (any pattern with an unescaped /) failed to compile and always returned false
• [abc] used the brackets as delimiters, so the character class was lost
• /abc/i was matched case-insensitively instead of literally
• an empty pattern returned false instead of matching everything
• the property value was passed to preg_match as-is: null short-circuited to false, true became "1", and an array property threw a TypeError out of getFeatureFlag because Client only catches Exception

The flags service (rust/feature-flags/src/properties/property_matching.rs) compiles the filter value as the pattern and converts the property value to a string with the same rules used for the other string operators. The regex requirement in PostHog/sdk-specs local-feature-flag-evaluator says the same. This change makes the PHP SDK do that:

• the pattern and property are converted to strings with valueToString
• the pattern is wrapped in /.../u, with any slash that isn't already escaped escaped
• invalid patterns still return false for both operators
• a preg_match execution failure is now inconclusive, so not_regex cannot match on an error

testMatchPropertyWithNones expected regex "null" against a null property to be false. The flags service compares against the string "null", so it is now true.

💚 How did you test it?

• Added a data-provider test covering slashes, escaped slashes, bracket classes, slash-wrapped values, empty and invalid patterns, case sensitivity, Unicode, and non-string property values (null, bool, float, array). Every expected value was checked against the flags service matcher, compiled from rust/feature-flags and run on the same inputs.
• Added a test that a regex execution failure (invalid UTF-8 input) is inconclusive for both operators.
• Added a Client-level test with only_evaluate_locally for a URL regex flag and an array property; it returned false before this change.
• Ran the full PHPUnit suite on PHP 8.2, 8.3 and 8.5 (758 tests), plus phpcs, composer api:check, and the sdk_compliance_adapter unit tests.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm change to generate a change intent file

🤖 Agent context

Autonomy: Human-driven (agent-assisted). DRI: @quotentiroler (an outside contributor can't be set as assignee).

• Found and fixed with Claude Code; I reviewed and tested the change.
• The divergence came out of running one set of property-matching cases through every server SDK and the flags service's own matcher (compiled from rust/feature-flags). PHP was the only SDK that failed the slash and bracket cases, which the other six SDKs and the service agree on.
• The changeset was written by hand in the pnpm change format.

[marandaneto]

thanks @quotentiroler