WSDL Validator: Support for Emtpy Messages

[predic8]

Summary by CodeRabbit

• Bug Fixes

  • Improved SOAP/WSDL handling to skip validation for empty response bodies and to correctly handle messages with no defined parts (prevents spurious validation errors).

• Tests

  • Added test and sample WSDL to cover messages without parts, ensuring parsing and validation behave as expected.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 71c27a6c-07f3-47ea-a3b2-ef38d136aaad

📥 Commits

Reviewing files that changed from the base of the PR and between 05274fb and 13c3a09.

📒 Files selected for processing (1)

• core/src/test/java/com/predic8/membrane/core/util/soap/WSDLParserTest.java

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📝 Walkthrough

Walkthrough

Adds null-safe handling for WSDL messages with no parts, filters null parts in the extractor, updates WSDLValidator to skip empty-response bodies and branch on flow state, standardizes imports, and adds a test + WSDL fixture for empty messages.

Changes

WSDL Empty Message Handling and Validator Logic

Layer / File(s)	Summary
Message part null-safety core/src/main/java/com/predic8/membrane/core/util/wsdl/parser/Message.java	getPart() now returns null when no parts are defined; Javadoc updated to document "first part or null if no part is defined".
Message element extractor null filtering core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLMessageElementExtractor.java	Document-style parts pipeline filters out null results from Message::getPart to prevent downstream consumers from seeing missing parts.
WSDLValidator response and element validation core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLValidator.java	Early return for empty RESPONSE flow messages; element validation branches on Interceptor.Flow state rather than runtime instanceof checks while preserving SOAP fault handling.
AbstractXMLSchemaValidator import cleanup core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/AbstractXMLSchemaValidator.java	Wildcard imports replaced with explicit imports; local variable type changed from explicit List<Validator> to var.
Test coverage for empty messages core/src/test/java/com/predic8/membrane/core/util/soap/WSDLParserTest.java, core/src/test/resources/ws/special/empty-message.wsdl	New emptyMessage test verifies parsing of messages with zero parts; new WSDL test resource defines CityResponse message with no parts.

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🎯 3 (Moderate) | ⏱️ ~20 minutes

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Possibly Related PRs

• membrane/api-gateway#2871: Both PRs directly modify WSDLValidator.validateMessage response validation control flow and fault-handling logic.

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Suggested Reviewers

• rrayst

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🐰 I found a WSDL with nothing inside,

so I hopped and made the code more wide-eyed.

Nulls are filtered, validators neat,

Tests added too — now parsing's complete! ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title contains a typo ('Emtpy' instead of 'Empty') and clearly describes the main change: adding support for empty WSDL messages in the validator.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch wsdl-validator-emtpy-messages

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLValidator.java (1)

104-107: 💤 Low value

Consider the log level and request handling.

Two observations:

1. Log level: Using log.info() for skipping validation of empty responses might be verbose. Consider log.debug() since this is an expected condition that doesn't require operator attention.

2. Request handling: This early return only applies to RESPONSE flow. Should empty request bodies also skip validation, or is this response-specific by design?

The response-only handling appears intentional based on the PR scope (WSDL operations can have empty responses), but verifying the design intent would be helpful.

💡 Optional: Change to debug level

-            log.info("Skipping validation of empty response.");
+            log.debug("Skipping validation of empty response.");

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In
`@core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLValidator.java`
around lines 104 - 107, In WSDLValidator update the log level for the
empty-response early-return: in the conditional that checks (flow ==
Interceptor.Flow.RESPONSE && message.isBodyEmpty()) replace the use of
log.info(...) with log.debug(...) so skipping validation of expected empty
responses is logged at a debug level; keep the early return behavior as-is
(response-only) since this PR is response-scoped but confirm separately if empty
requests should also be skipped in a future change.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@core/src/test/java/com/predic8/membrane/core/util/soap/WSDLParserTest.java`:
- Around line 199-217: The test emptyMessage in WSDLParserTest should verify the
new null-return behavior of Message.getPart(): after locating the Message
instance (msg) with name "CityResponse" and asserting msg.getParts().size() ==
0, add an assertion that msg.getPart() returns null (or is null) to cover the PR
change to Message.getPart(). Ensure you reference the same msg variable and keep
the check right after the existing part-size assertion.

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Nitpick comments:
In
`@core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLValidator.java`:
- Around line 104-107: In WSDLValidator update the log level for the
empty-response early-return: in the conditional that checks (flow ==
Interceptor.Flow.RESPONSE && message.isBodyEmpty()) replace the use of
log.info(...) with log.debug(...) so skipping validation of expected empty
responses is logged at a debug level; keep the early return behavior as-is
(response-only) since this PR is response-scoped but confirm separately if empty
requests should also be skipped in a future change.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: f8f6c152-d840-4d4d-8913-ecd6c2b109bd

📥 Commits

Reviewing files that changed from the base of the PR and between b6622e0 and 05274fb.

📒 Files selected for processing (6)

• core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/AbstractXMLSchemaValidator.java
• core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLMessageElementExtractor.java
• core/src/main/java/com/predic8/membrane/core/interceptor/schemavalidation/WSDLValidator.java
• core/src/main/java/com/predic8/membrane/core/util/wsdl/parser/Message.java
• core/src/test/java/com/predic8/membrane/core/util/soap/WSDLParserTest.java
• core/src/test/resources/ws/special/empty-message.wsdl