Add a Copilot-specific GitHub Enterprise provider

[slang25]

Fixes #277435

Summary

• Add a dedicated github-enterprise-copilot authentication provider and a new github.copilot.enterprise.uri setting for Copilot-specific enterprise auth
• Switch Copilot enterprise auth, domain resolution, and MCP resolution to the new provider while keeping fallback to github-enterprise.uri for compatibility
• Preserve the existing github-enterprise provider and legacy setting for GitHub PR/Issues and other GitHub integrations
• Update setup, onboarding, and default account flows to recognize the new Copilot enterprise provider while honoring the legacy enterprise path
• Add targeted coverage for provider selection and legacy URI fallback

Validation

• Core typecheck: npm run compile-check-ts-native
• Extension builds:
  • npm run gulp -- compile-extension:github-authentication
  • npm run gulp -- compile-copilot-extension-build
• Targeted Copilot tests:
  • npm --prefix extensions/copilot run test:unit -- src/extension/githubMcp/test/node/githubMcpDefinitionProvider.spec.ts src/extension/test/vscode-node/session.test.ts
  • npm --prefix extensions/copilot run test:extension -- --grep "should use the Copilot enterprise provider if configured"
• Hygiene: node --experimental-strip-types build/hygiene.ts <changed files>

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@TylerLeonhardt

Matched files:

• extensions/github-authentication/package.json
• extensions/github-authentication/package.nls.json
• extensions/github-authentication/src/extension.ts
• extensions/github-authentication/src/github.ts

[Copilot]

Pull request overview

Adds a Copilot-dedicated GitHub Enterprise authentication provider (github-enterprise-copilot) and a Copilot-specific enterprise URI setting (github.copilot.enterprise.uri) so Copilot can target a different GHES/GHE.com host than other GitHub extensions, while retaining legacy compatibility via fallback to github-enterprise.uri.

Changes:

• Introduces a new github-enterprise-copilot auth provider and wires it through product config, onboarding/setup, and default account selection with legacy-provider compatibility.
• Updates Copilot enterprise domain/MCP resolution to use the new provider and Copilot-specific URI setting, with fallback to the legacy URI.
• Adds/updates targeted unit and extension tests to cover provider selection and URI fallback behavior.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/vs/workbench/services/accounts/browser/defaultAccount.ts	Default account provider selection now recognizes legacy enterprise provider IDs and falls back to legacy enterprise URI setting.
src/vs/workbench/contrib/welcomeOnboarding/browser/onboardingVariationA.ts	Onboarding enterprise sign-in telemetry/provider id updated; enterprise URI detection now falls back to legacy setting.
src/vs/workbench/contrib/chat/browser/chatSetup/chatSetupController.ts	Chat setup enterprise URI detection now falls back to legacy setting.
src/vs/workbench/contrib/chat/browser/actions/chatActions.ts	Context key expression for “non-enterprise” Copilot users updated to exclude both enterprise provider IDs.
product.json	Default chat agent enterprise provider id and provider URI setting switched to Copilot-specific values; registers new provider usage mapping.
extensions/github-authentication/src/github.ts	Authentication provider registration now supports overriding provider id/label for GHES-based providers.
extensions/github-authentication/src/extension.ts	Registers both enterprise providers (legacy + Copilot) with primary/fallback URI settings and dynamic re-init on config changes.
extensions/github-authentication/package.nls.json	Adds localized description string for the new Copilot enterprise URI setting.
extensions/github-authentication/package.json	Contributes new auth provider id and new github.copilot.enterprise.uri setting; restricts it in untrusted workspaces.
extensions/copilot/src/platform/endpoint/node/domainServiceImpl.ts	Domain resolution now uses Copilot enterprise URI helper and recognizes enterprise provider via helper predicate.
extensions/copilot/src/platform/configuration/common/configurationService.ts	Adds GitHubEnterpriseCopilot to the Copilot AuthProviderId enum.
extensions/copilot/src/platform/authentication/common/authentication.ts	Adds constants + helpers for Copilot enterprise URI (with legacy fallback) and enterprise-provider detection.
extensions/copilot/src/extension/test/vscode-node/session.test.ts	Updates session selection test to expect github-enterprise-copilot provider id.
extensions/copilot/src/extension/githubMcp/test/node/githubMcpDefinitionProvider.spec.ts	Updates tests to use Copilot enterprise URI setting and adds coverage for legacy URI fallback + change events.
extensions/copilot/src/extension/githubMcp/common/githubMcpDefinitionProvider.ts	MCP definition provider now reads Copilot enterprise URI with legacy fallback and reacts to both settings.
extensions/copilot/CONTRIBUTING.md	Updates contributed product override examples for new provider id and Copilot enterprise URI setting.

Comments suppressed due to low confidence (1)

src/vs/workbench/services/accounts/browser/defaultAccount.ts:900

• getEnterpriseUrl() uses nullish coalescing (??) to fall back to the legacy setting. If the Copilot-specific setting is explicitly set to an empty string (which the schema pattern allows), this will not fall back and will attempt new URL(''), throwing and causing enterprise endpoints to silently fall back to the non-enterprise URLs. Consider treating empty/whitespace strings as "unset" (e.g., use || or validate value.trim().length > 0 before constructing the URL) so the legacy fallback works as intended.

		const value = this.configurationService.getValue(this.defaultAccountConfig.authenticationProvider.enterpriseProviderUriSetting)
			?? this.configurationService.getValue(this.defaultAccountConfig.authenticationProvider.enterpriseProviderUriFallbackSetting);
		if (!isString(value)) {
			return undefined;
		}
		return new URL(value);
	}

[XavierMP14]

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