Suppress UNC host access errors from unhandled-error telemetry

[Copilot]

Suppresses ERR_UNC_HOST_NOT_ALLOWED errors from being reported as unhandled errors in telemetry. These errors originate from a user-configured allowlist (security.allowedUNCHosts) and represent an expected access denial rather than a bug.

Changes Made

• src/vs/platform/files/node/diskFileSystemProvider.ts: When mapping a Node.js error to a FileSystemProviderError, treat ERR_UNC_HOST_NOT_ALLOWED as NoPermissions (instead of Unknown) and mark the resulting error as no-telemetry so it does not surface in unhandled-error telemetry.
• src/vs/base/common/errors.ts: Added a markAsErrorNoTelemetry helper that flags an existing Error instance as no-telemetry while preserving its original class, prototype chain, name, and additional properties. The flag is implemented as an internal __vscodeNoTelemetry property on the error rather than by mutating error.name. This avoids side effects for errors that encode semantics in name — most importantly FileSystemProviderError, whose name carries the FileSystemProviderErrorCode across IPC boundaries. ErrorNoTelemetry.isErrorNoTelemetry checks the new flag and still recognizes the legacy name === 'CodeExpectedError' for compatibility with deserialized errors.
• src/vs/base/test/common/errors.test.ts: Added a unit test verifying that markAsErrorNoTelemetry preserves the original error class, name, message, and additional properties while making the error detectable as no-telemetry.

Testing

• ✅ TypeScript compilation passes (npm run compile-check-ts-native)
• ✅ ESLint passes for the modified files
• ✅ Unit test added for markAsErrorNoTelemetry

[Copilot]

Pull request overview

This PR aims to prevent UNC host access-denial errors (ERR_UNC_HOST_NOT_ALLOWED)—which result from a user-configured security policy—from being reported as unhandled-error telemetry by marking them as “no telemetry” while also mapping them to a permissions-related file-system error code.

Changes:

• Map ERR_UNC_HOST_NOT_ALLOWED to FileSystemProviderErrorCode.NoPermissions in DiskFileSystemProvider.toFileSystemProviderError().
• Introduce markAsErrorNoTelemetry(error) as a helper to mark an existing error instance as “no telemetry” without wrapping it.
• Add a unit test validating that markAsErrorNoTelemetry preserves the original error instance/type/properties.

Show a summary per file

File	Description
src/vs/platform/files/node/diskFileSystemProvider.ts	Treat UNC-host-denied as NoPermissions and attempt to suppress telemetry by marking the provider error as no-telemetry.
src/vs/base/common/errors.ts	Add markAsErrorNoTelemetry helper that marks an error by mutating its name.
src/vs/base/test/common/errors.test.ts	Add test ensuring markAsErrorNoTelemetry preserves instance/type/properties while being detected as no-telemetry.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 3

[Copilot]

markAsErrorNoTelemetry(providerError) overwrites FileSystemProviderError.name. For file-system errors, the name field is used to carry the FileSystemProviderErrorCode across IPC boundaries (because the IPC channel only serializes message/name/stack for Error instances), and toFileSystemProviderErrorCode() relies on that name format when the error is no longer an actual FileSystemProviderError. With name set to CodeExpectedError, callers in other processes will see this as Unknown (and lose the intended NoPermissions semantics). Consider avoiding name mutation for FileSystemProviderError and instead propagating an explicit no-telemetry marker (e.g. include a noTelemetry/code field in IPC error serialization, or update the no-telemetry mechanism to not repurpose name).

[bryanchen-d]

instead of any, can we just cast it to a Record<> with the noTelemetryFlag property?

[bryanchen-d]

@copilot can you fix this?

[Copilot]

Replaced the any casts with a typed ErrorWithNoTelemetryFlag = Error & { [noTelemetryFlag]?: boolean } alias used for both setting and reading the flag. Done in 6f3dfaf.