[Monitor Server] Format results in List<JsonNode>

[thangqp]

PR Summary

• To make it easier to view the results during monitoring development, we return a List<JsonNode>.
• Note that the return type can be changed later when developing the front end.

[coderabbitai]

📝 Walkthrough

Walkthrough

The MonitorController was modified to deserialize string-based execution results into JSON nodes. Jackson dependencies were introduced, the constructor now accepts an ObjectMapper, and the getExecutionResults method's return type changed from List to List, with per-item parsing and error handling added.

Changes

Cohort / File(s)	Summary
Result Deserialization monitor-server/src/main/java/org/gridsuite/monitor/server/controllers/MonitorController.java	Modified constructor to inject ObjectMapper; updated getExecutionResults to parse string results into JsonNode objects with JsonProcessingException error handling; changed return type from List to List.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

A controller hops through strings so plain,
And turns them into JSON's domain,
With ObjectMapper's parsing grace,
Each result finds its proper place,
Data flowers bloom in structured rain! 🐰✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title '[Monitor Server] Format results in List' clearly and specifically describes the main change—converting the results return type to List for improved viewing during monitoring development.
Description check	✅ Passed	The description directly relates to the changeset, explaining the rationale for returning List and noting the return type may evolve with front-end development.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch monitor_server_format_results_json_node

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[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In
`@monitor-server/src/main/java/org/gridsuite/monitor/server/controllers/MonitorController.java`:
- Around line 74-80: The error message in MonitorController is misleading and
nulls can cause NPEs: change the exception text in the objectMapper.readValue
handler to say "Unable to deserialize result from JSON: <resultString>" (or
similar) and guard against null entries from results before calling readValue;
e.g., filter the results stream with Objects::nonNull or add an explicit null
check in the lambda so nulls are handled (throw a clear IllegalStateException
like "Result is null" or skip them), referencing the results variable, the
objectMapper.readValue(...) call, and the lambda in the stream.

[coderabbitai]

⚠️ Potential issue | 🟡 Minor

Error message incorrectly says "serialize" instead of "deserialize".

The operation readValue is deserialization (parsing JSON string to object), not serialization. Additionally, if resultString is null, this will throw a NullPointerException rather than the expected JsonProcessingException.

Proposed fix

         List<JsonNode> resultsJsonNode = results.stream().map(resultString -> {
             try {
                 return objectMapper.readValue(resultString, JsonNode.class);
             } catch (JsonProcessingException e) {
-                throw new IllegalStateException(String.format("Unable to serialize result to JSON: %s", resultString), e);
+                throw new IllegalStateException(String.format("Unable to deserialize result from JSON: %s", resultString), e);
             }
         }).toList();

If null results are possible from monitorService.getResults(), consider filtering them out or handling explicitly:

List<JsonNode> resultsJsonNode = results.stream()
    .filter(Objects::nonNull)
    .map(resultString -> { ... })
    .toList();

🤖 Prompt for AI Agents

In
`@monitor-server/src/main/java/org/gridsuite/monitor/server/controllers/MonitorController.java`
around lines 74 - 80, The error message in MonitorController is misleading and
nulls can cause NPEs: change the exception text in the objectMapper.readValue
handler to say "Unable to deserialize result from JSON: <resultString>" (or
similar) and guard against null entries from results before calling readValue;
e.g., filter the results stream with Objects::nonNull or add an explicit null
check in the lambda so nulls are handled (throw a clear IllegalStateException
like "Result is null" or skip them), referencing the results variable, the
objectMapper.readValue(...) call, and the lambda in the stream.