fix(tls): replace unimplemented!() with proper error for TLS resolver

[techcodie]

• Add ResolverNotSupported error variant to TlsError enum
• Replace unimplemented!() panics with proper error returns in create_client_config
• Improves error handling by returning graceful errors instead of panicking

fix(tsc): improve error message for invalid 'this' parameter syntax

• Add helpful error message rewrite for TS2684 (invalid 'this' parameter)
• Provides guidance on correct React/Preact component typing syntax
• Helps users understand the difference between 'this' parameter and function return types

[coderabbitai]

Walkthrough

Two changes across TypeScript compiler diagnostics and TLS error handling: (1) New diagnostic rewrite branch for code 2684 handling 'this' parameter messages with React/Preact component typing guidance; (2) New TlsError variant replacing unimplemented!() when resolver-based TLS keys are used in client connections.

Changes

Cohort / File(s)	Summary
TypeScript Compiler Diagnostics cli/tsc/go.rs	Added new diagnostic rewrite branch in maybe_rewrite_message for code 2684. When message contains "'this' parameter", appends a note explaining that the 'this' parameter types the context rather than the function return type, with example patterns for typing React/Preact components (FC<Props> or function returning JSX.Element).
TLS Error Handling ext/tls/lib.rs	Introduced new public error variant ResolverNotSupported in the TlsError enum. Updated create_client_config to return Err(TlsError::ResolverNotSupported) instead of unimplemented!() when TlsKeys::Resolver(_) is encountered in both code paths (with and without unsafely_ignore_certificate_errors).

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• cli/tsc/go.rs: Straightforward conditional branch addition with message formatting logic; limited scope and isolated to diagnostic rewriting
• ext/tls/lib.rs: Simple enum variant addition and direct replacement of panic paths with explicit error returns; well-contained change with clear intent

Poem

🐰 A fuzzy-eared fix in the TypeScript stream,
Where 'this' now whispers its React-component dream,
And over in TLS, no more panics to fear—
Just proper resolver errors, crystal and clear!

Pre-merge checks and finishing touches

❌ 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%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: replacing unimplemented!() with a proper TlsError for TLS resolver handling. However, it focuses only on the TLS change and omits the significant TSC error message improvement also included in the changeset.
Description check	✅ Passed	The description is well-organized and clearly relates to the changeset, covering both the TLS resolver error handling fix and the TSC error message improvements with appropriate context and rationale.

✨ Finishing touches

• 📝 Generate docstrings

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• Create PR with unit tests
• Post copyable unit tests in a comment

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📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 3c0f289 and 738f856.

📒 Files selected for processing (2)

• cli/tsc/go.rs (1 hunks)
• ext/tls/lib.rs (3 hunks)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (11)

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🔇 Additional comments (2)

cli/tsc/go.rs (1)

185-189: TS2684 rewrite looks good; guidance is clear and preserves original message

This branch cleanly appends React/Preact-specific guidance while keeping the original TS2684 text intact and is gated on both the code and a 'this' parameter substring, which should keep it reasonably targeted.

One minor thought: since this depends on TypeScript’s exact phrasing, it may be worth keeping an eye on upstream TS message wording changes so we don’t silently stop applying this rewrite or start applying it in cases where the React/Preact note is less relevant.

ext/tls/lib.rs (1)

54-57: Replacing unimplemented!() with ResolverNotSupported is a solid behavioral improvement

The new TlsError::ResolverNotSupported variant and its use in both TlsKeys::Resolver(_) match arms make the client config path fail gracefully instead of panicking, which is much better for robustness and user-facing error handling.

The chosen error class "NotSupported" and message clearly communicate that resolver-based keys are only intended for server-side usage.

The only follow-up to double-check is:

• Any exhaustive matches on TlsError in this crate or downstream consumers that may now need to handle ResolverNotSupported.
• Error expectation tests for client TLS config that may previously have assumed a panic and should now assert on this specific variant / JS error class.

Otherwise, this change aligns well with the stated PR goal.

Also applies to: 316-318, 351-353

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