fix(connector): [WORLDPAY] parse refused responses when refusalCode or refusalDescription is missing

[errmakov]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

Description

WorldpayPaymentResponseFields was an untagged enum, and its RefusedResponse variant required both refusalCode and refusalDescription. When Worldpay refuses a payment and sends only one of them, the body matches no variant, and because other_fields is a flattened Option, serde silently deserializes it as None instead of failing. The payment is still marked Failure (from outcome: refused), but the connector response carries no error code or message, so the decline reason is lost.

Checked against the pre-fix types: {"outcome": "refused", "refusalDescription": "Do not honour"} deserializes to Ok(WorldpayPaymentsResponse { outcome: Refused, other_fields: None }).

As suggested in the review of #8763, simply making the two fields optional isn't enough: with an untagged enum, almost any body would then match RefusedResponse. This PR:

• Implements Deserialize for WorldpayPaymentsResponse by hand (crates/hyperswitch_connectors/src/connectors/worldpay/response.rs). It reads outcome and transactionReference, then parses the remaining fields into the shape that outcome implies:

  • refused → RefusedResponse
  • 3dsDeviceDataRequired → DDCResponse
  • 3dsChallenged → ThreeDsChallenged
  • fraudHighRisk → FraudHighRisk
  • authorized, sentForSettlement, sentForRefund, sentForPartialRefund, sentForCancellation, 3dsAuthenticationFailed, 3dsUnavailable → AuthorizedResponse

  Every outcome is matched explicitly. A body that doesn't match its outcome's shape (e.g. a cancellation response with only _links) still has no extra fields, as before, but the mismatch is now logged as a warn with the outcome, the expected fields type and the error. The logged error omits response values; only missing field messages are kept verbatim.

• Removes the derived Deserialize from WorldpayPaymentResponseFields (it keeps Serialize), so the ambiguous untagged deserialization can't be used by accident.

• Makes RefusedResponse.refusal_code and refusal_description Option<String>, keeping the existing comment on the raw response code.

• In crates/hyperswitch_connectors/src/connectors/worldpay/transformers.rs, when a refusal field is missing, ErrorResponse.code / message fall back to NO_ERROR_CODE / NO_ERROR_MESSAGE. reason, network_decline_code and network_error_message are left None rather than filled with a placeholder, so a placeholder is never reported as coming from the card network.

Additional Changes

• This PR modifies the API contract
• This PR modifies the database schema
• This PR modifies application configuration/environment variables

Motivation and Context

Fixes #8749

Supersedes #8763, which stalled on the review asking for a custom deserializer.

How did you test it?

Unit tests (connectors::worldpay::response::tests, 13 new), run with cargo test -p hyperswitch_connectors --features v1,payouts,frm --lib worldpay::response::tests:

Response body	Parsed as
refused with refusalCode, refusalDescription, advice, riskFactors	RefusedResponse, all fields kept
refused with only refusalDescription	RefusedResponse, code None
refused with only refusalCode	RefusedResponse, description None
refused with neither	RefusedResponse, both None
authorized with paymentInstrument, _links, _actions	AuthorizedResponse
3dsDeviceDataRequired	DDCResponse
3dsChallenged	ThreeDsChallenged
fraudHighRisk	FraudHighRisk
sentForCancellation with only _links	no extra fields
refused with a numeric refusalCode	no extra fields (mismatch logged)
no outcome	deserialization error

Two more tests cover the logged error detail: a missing field keeps its name, and a mistyped value is not echoed.

The tests failed to compile before the change (refusal fields were String) and all 13 pass after it.

• cargo +nightly fmt applied.
• cargo clippy -p hyperswitch_connectors --features v1,payouts,frm --all-targets reports no warnings in hyperswitch_connectors.
• Not tested against a live Worldpay sandbox; the response bodies in the tests follow the shapes the existing structs already expect.

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible

🤖 Generated with Claude Code

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
crates/hyperswitch_connectors/src/connectors/worldpay/transformers.rs	83% smaller
crates/hyperswitch_connectors/src/connectors/worldpay/response.rs	Unsupported file format

[XyneSpaces]

[should-fix] parse_fields at crates/hyperswitch_connectors/src/connectors/worldpay/response.rs:80 uses serde_json::from_value(fields).ok() and silently drops deserialization errors.

A type mismatch or unexpected shape in a Worldpay response will be discarded as None, making integration issues hard to detect and affecting downstream error/code extraction. Consider logging the error or propagating it instead of swallowing it with .ok().

[XyneSpaces]

⚠️ parse_fields in crates/hyperswitch_connectors/src/connectors/worldpay/response.rs silently discards serde deserialization errors via .ok(), so a malformed refusal response (e.g., a wrong field type) is reported as other_fields: None instead of failing parsing.

Replace the custom Deserialize impl with #[serde(default)] on the new Option<String> fields in RefusedResponse and keep the derived Deserialize on the untagged enum; this fixes the missing-field case without swallowing real parse errors.

[XyneSpaces]

[should-fix] Deserialization failure is silently dropped

crates/hyperswitch_connectors/src/connectors/worldpay/response.rs:78 uses serde_json::from_value(fields).ok(), converting parse errors into None without logging. This makes malformed Worldpay responses impossible to debug and can mask integration breakage. Return Result<T, serde_json::Error> and propagate or log the error instead of using .ok().

[errmakov]

@XyneSpaces thanks for the review. Addressed in fb6cb31.

Silently dropped errors. parse_fields now logs a warn with the outcome, the expected fields type and the error before returning None, so a Worldpay response that doesn't match its outcome is visible in the logs. The logged error omits response values, since serde quotes them in messages like invalid type: string "..." and they can include tokens or JWTs; missing field messages are kept as they are. Covered by refused_with_mistyped_field_has_no_other_fields, deserialization_error_detail_keeps_missing_field_name and deserialization_error_detail_omits_response_values.

I kept the result lenient rather than propagating the error:

• Capture, void and refund responses (sentForSettlement, sentForCancellation, sentForRefund) legitimately carry only _links, so failing on a mismatch would break those flows.
• A refusal with one unexpected value, for example a new riskFactors type from Worldpay, should still be recorded as a failed payment, not become a response deserialization error.
• It matches the behaviour before this PR, where the flattened Option also became None on a mismatch, just without a log.

#[serde(default)] with the derived untagged enum. That brings back the problem raised in the review of #8763. Serde already treats a missing Option field as None, so once refusalCode and refusalDescription are optional, RefusedResponse accepts almost any object. As the first variant of an untagged enum, it would also match authorized, 3DS challenge and device data collection responses, and those payments would lose their redirect and mandate data. Reading outcome first avoids that.

[XyneSpaces]

[should-fix] The Reason::Refused arm maps refusal details to ErrorReason, but the catch-all _ => None silently drops every other refusal-shaped variant. This loses the actual refusal code/description that the PR title says should now be handled.

Either exhaustively map all refusal variants or preserve the raw refusal object in the fallback arm instead of returning None.

[errmakov]

@XyneSpaces I think this one doesn't match the code in this PR: there is no Reason::Refused arm or ErrorReason type in the Worldpay connector, and the PR doesn't add a _ => None.

The closest _ => None is the existing optional_error_message match (transformers.rs#L910-L919), which only supplies messages for 3dsAuthenticationFailed, 3dsUnavailable and fraudHighRisk. Refusal details don't go through it:

• The RefusedResponse arm (L893) carries refusalCode, refusalDescription and advice.code.
• The Err(ErrorResponse { .. }) arm (L955) turns them into code, message, network_decline_code, network_error_message and network_advice_code.

A refused response takes that path whether both refusal fields are present, only one, or neither. The only exception is a body whose fields have the wrong type (e.g. a numeric refusalCode), which is logged as a mismatch and has no extra fields, as covered by refused_with_mistyped_field_has_no_other_fields.