fix: minor tweaks to enable vscode integration MCP-134

[nirinchev]

Proposed changes

This tweaks slightly some of the API around streamable http runner to allow it to be consumed by the vscode extension. Notably:

• We add httpHeaders config option that allows consumers to specify required headers the server should check for in the client requests. This will be used by the vscode extension to generate a random header when it starts the server.
• Exports some more types for consumers (e.g. StreamableHttpRunner and defaultUserConfig)
• Allows running the http server on a random port and exposes the address of the server.

[Copilot]

Pull Request Overview

This PR adds VS Code extension integration support by enhancing the StreamableHttpRunner with header validation, port flexibility, and better type exports.

• Adds httpHeaders configuration option for server-side header validation
• Enables random port assignment and exposes server address via getter
• Exports additional types (StreamableHttpRunner, defaultUserConfig) for external consumption

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/common/config.ts	Adds httpHeaders field to config interface and default configuration
src/transports/streamableHttp.ts	Implements header validation middleware and address getter for server
src/lib.ts	Exports additional types and classes for external consumption
tests/integration/transports/streamableHttp.test.ts	Updates tests to validate header functionality with comprehensive test cases

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[gagik]

Looks good, one suggestion

[gagik]

Suggested change

	private constructor(logger: LoggerBase, timeout: number = DEVICE_ID_TIMEOUT) {
	this.logger = logger;
	this.timeout = timeout;
	this.getMachineId = (): Promise<string> => nodeMachineId.machineId(true);
	this.abortController = new AbortController();
	this.deviceIdPromise = DeviceId.UnknownDeviceId;
	private constructor({logger, timeout, deviceIdPromise, abortController}: {logger: LoggerBase, timeout: number = DEVICE_ID_TIMEOUT, deviceIdPromise: Promise<string>, abortController: AbortController}) {
	this.logger = logger;
	this.timeout = timeout;
	this.abortController = abortController;
	this.deviceIdPromise = deviceIdPromise;

I think this is better because it'd be good to have the Promise resolve to unknown only in the end so we can always have a state of pending -> unknown and not unknown -> pending -> unknown (even though in practice we instantly override this in create right now

[nirinchev]

Unfortunately, we can't supply the promise through the constructor since we need the DeviceId instance to construct the promise itself. Technically, the only reason to have it assigned here is to make the types nicer and ensure we don't have to write ? all over the place when we know for sure the field is initialized at this point. So we have 3 options (with no preference which one to go for):

1. Keep it as is
2. Suppress the error that we're not initializing a required field
3. Move the getDeviceId call to the constructor (and close our eyes for the fact it's introducing a side effect)

[gagik]

Suggested change

	public static create(logger: LoggerBase, timeout?: number): DeviceId {
	public static create(logger: LoggerBase, { timeout = DEVICE_ID_TIMEOUT } : { timeout: number} = {}): DeviceId {
	const abortController = new AbortController();
	const deviceIdPromise = () => getDeviceId({
	getMachineId: () => nodeMachineId.machineId(true),
	onError: (reason, error) => {
	this.handleDeviceIdError(reason, String(error));
	},
	timeout: this.timeout,
	abortSignal: abortController.signal,
	});
	const instance = new DeviceId({logger, timeout, deviceIdPromise, abortController});

personal preference re: timeout as object because it's one of these things which we basically largely have only for test DI purposes