Refactor JSON processing to exclude "method" in serialization

[devcrocod]

#56

Motivation and Context

fix bug

How Has This Been Tested?

unit tests and manual testing

Breaking Changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

[Copilot]

Pull Request Overview

This PR refactors JSON processing to ensure the "method" field is excluded during serialization and properly handled during deserialization for both Request and Notification objects. This addresses a bug where the method field was being incorrectly included in the serialized JSON parameters.

• Modifies JSON serialization to exclude "method" field from parameters during encoding
• Updates deserialization logic to reconstruct the method field from the JSON-RPC method property
• Consolidates notification serialization to use the standardized toJSON() function

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
types.kt	Updates Request and Notification serialization/deserialization to properly handle method field exclusion and reconstruction
Protocol.kt	Refactors notification sending to use the standardized toJSON() method instead of inline serialization

Comments suppressed due to low confidence (3)

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types.kt:128

• [nitpick] The variable name encoded is misleading since it represents a modified JSON object with the method field removed, not the full encoded representation. Consider renaming to paramsWithoutMethod or filteredParams for clarity.

    val encoded = JsonObject(McpJson.encodeToJsonElement(this).jsonObject.minus("method"))

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types.kt:142

• [nitpick] The variable name requestData could be more descriptive. Consider renaming to paramsWithMethod or reconstructedParams to clearly indicate what this variable represents.

    val requestData = JsonObject(params.jsonObject.plus("method" to JsonPrimitive(method)))

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types.kt:183

• [nitpick] The variable name data is too generic. Consider using a more descriptive name like paramsWithMethod to match the pattern used in the Request deserialization function.

    val data = JsonObject(params.jsonObject.plus("method" to JsonPrimitive(method)))

[Copilot]

The function signature changed from returning Request? to Request, removing null safety. This is a breaking change that could cause issues if callers were handling null returns. Consider maintaining the nullable return type or ensuring all call sites are updated to handle potential exceptions.

Suggested change

	internal fun JSONRPCRequest.fromJSON(): Request {
	val requestData = JsonObject(params.jsonObject.plus("method" to JsonPrimitive(method)))
	val deserializer = selectRequestDeserializer(method)
	return McpJson.decodeFromJsonElement(deserializer, requestData)
	internal fun JSONRPCRequest.fromJSON(): Request? {
	val requestData = JsonObject(params.jsonObject.plus("method" to JsonPrimitive(method)))
	val deserializer = selectRequestDeserializer(method)
	return try {
	McpJson.decodeFromJsonElement(deserializer, requestData)
	} catch (e: Exception) {
	null
	}