fix: remove dead code after tools throw and fix transport leak on connect error

[matingathani]

Changes

Two unrelated bugs fixed in a single PR.

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Bug 1 — Dead code after unconditional throw in language model providers

Files: llm/ai-sdk/provider/stripe-language-model.ts, llm/ai-sdk/provider/stripe-language-model-v3.ts

Both getArgs() methods threw unconditionally when options.tools was non-empty, but the code immediately following the throw computed tools and toolChoice variables that could never be reached:

// throw fires here when tools are present
if (options.tools && options.tools.length > 0) {
  throw new Error('Tool calling is not supported...');
}

// ❌ These lines are unreachable — tools is always undefined after the throw
const tools = options.tools && options.tools.length > 0
  ? options.tools.map(...)
  : undefined;

let toolChoice = ...;
if (options.toolChoice) { ... }
...
if (tools !== undefined) body.tools = tools;        // never executes
if (toolChoice !== undefined) body.tool_choice = toolChoice; // never executes

Fix: Removed the 30–40 lines of unreachable tools/toolChoice computation from both files.

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Bug 2 — Transport connection leak in TypeScript MCP client

File: tools/typescript/src/shared/mcp-client.ts

In doConnect(), if client.connect() succeeded but the subsequent client.listTools() call threw an error, the catch block nulled out this.client and this.transport without closing the active connection first, leaking the underlying transport:

} catch (error) {
  // ❌ Active connection was abandoned here — client.close() never called
  this.client = null;
  this.transport = null;
  throw ...;
}

Fix: Call await this.client.close() before clearing references so the MCP connection is properly torn down on any connect-phase failure.

---

Testing

• llm/ai-sdk: 327 tests pass
• tools/typescript: 55 tests pass

[Copilot]

Pull request overview

Fixes two bugs across the AI SDK Stripe language model providers and the TypeScript MCP client: removing unreachable tool-handling code paths and ensuring MCP connections are properly closed on connect-phase failures.

Changes:

• Removed unreachable tools (and related) request-body construction in Stripe language model providers when tool calling is unsupported.
• Added connect-error cleanup in StripeMcpClient to close an established MCP connection before clearing references.
• Minor formatting/cleanup in request-body optional parameter handling.

Reviewed changes

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

File	Description
tools/typescript/src/shared/mcp-client.ts	Closes the MCP client during connect failure cleanup to prevent transport leaks.
llm/ai-sdk/provider/stripe-language-model.ts	Removes dead tool/tool-choice request construction after the “tools unsupported” throw.
llm/ai-sdk/provider/stripe-language-model-v3.ts	Same dead-code removal for the V3 provider variant.

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[Copilot]

The new cleanup closes this.client, but there’s no test coverage that close() is invoked when connect() succeeds and listTools() throws. Adding a Jest test that mocks listTools to reject and asserts client.close is awaited (and that connect() rejects with the wrapped error) would prevent regressions of the transport leak fix.

[Copilot]

After removing the toolChoice mapping, options.toolChoice is now silently ignored when options.tools is empty. Since tool calling is explicitly unsupported, it would be clearer/safer to also reject options.toolChoice (or at least warn) and update the error message to mention toolChoice as unsupported, to avoid a behavior change that’s hard for callers to notice.

[Copilot]

options.toolChoice is no longer forwarded (and is silently ignored) when options.tools is empty. Given the explicit “tool calling not supported” stance, consider explicitly throwing when toolChoice is provided as well (and adjusting the message), so callers don’t think the setting is taking effect.

Suggested change

	if (options.toolChoice !== undefined) {
	throw new Error(
	'Tool calling is not supported by the Stripe AI SDK Provider. ' +
	'The llm.stripe.com API does not currently support function calling or tool use. ' +
	'Please remove the toolChoice parameter (and any tools) from your request.'
	);
	}