Refactor integration tests to use Testcontainers for TypeScript client and server

[skarpovdev]

Motivation and Context

Current approach relies on cloning the TypeScript SDK before all tests, which may increase flakiness and slows down the whole test suite. The changes in this PR introduce testcontainers library usage to have a docker image with the SDK already cloned. The tests use the image for both server and client interactions via port binding and directories mounting.

Dockerfile is used to build the image which is then uploaded to our internal JB Docker registry. This means that we no longer run the tests on the latest master of TypeScript SDK. It can help reduce flakiness, but we may not immediately see an issue if something changes in it. We may consider building and uploading a new image automatically on CI.

The tests are expected to fail on CI for now as TS_SDK_IMAGE needs to be added to the repository secrects.

How Has This Been Tested?

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

Additional context

[Copilot]

Pull Request Overview

This PR refactors integration tests to use Testcontainers for running TypeScript client and server components, replacing the previous approach of cloning the TypeScript SDK during test execution. The change aims to improve test reliability and performance by using a Docker image with the SDK pre-installed.

Key changes:

• Introduces Testcontainers library for managing Docker containers during tests
• Replaces direct process execution with containerized TypeScript clients and servers
• Adds a Dockerfile for building the TypeScript SDK container image

Reviewed Changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/utils/Dockerfile	New Dockerfile for TypeScript SDK container with Node.js and pre-installed dependencies
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/typescript/TsTestBase.kt	Major refactor to use Docker containers instead of local processes for TypeScript execution
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/typescript/sse/TsEdgeCasesTestSse.kt	Updates test methods to use new containerized client execution
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/typescript/sse/TsClientKotlinServerTestSse.kt	Simplifies client execution to use new containerized approach
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/typescript/sse/KotlinServerForTsClientSse.kt	Removes unused import
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/typescript/sse/KotlinClientTsServerTestSse.kt	Updates to use ContainerProcess instead of Process
kotlin-sdk-test/src/jvmTest/kotlin/io/modelcontextprotocol/kotlin/sdk/integration/typescript/sse/KotlinClientTsServerEdgeCasesTestSse.kt	Updates to use ContainerProcess instead of Process
kotlin-sdk-test/build.gradle.kts	Adds Testcontainers dependency
gradle/libs.versions.toml	Adds Testcontainers version configuration

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[kpavlov]

We may consider building and uploading a new image automatically on CI.

BTW, With test containers we may build image before run, without pushing it to docker registry.