protected registerLanguageProvider()

in client/src/common/client.ts [2549:2619]
70 lines of code
12 McCabe index (conditional complexity)

	protected registerLanguageProvider(options: RenameRegistrationOptions): [Disposable, RenameProvider] {
		const selector = options.documentSelector!;
		const provider: RenameProvider = {
			provideRenameEdits: (document, position, newName, token) => {
				if ($DocumentSelector.skipCellTextDocument(selector, document)) {
					return undefined;
				}
				const client = this._client;
				const provideRenameEdits: ProvideRenameEditsSignature = (document, position, newName, token) => {
					let params: RenameParams = {
						textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(document),
						position: client.code2ProtocolConverter.asPosition(position),
						newName: newName
					};
					return client.sendRequest(RenameRequest.type, params, token).then(
						client.protocol2CodeConverter.asWorkspaceEdit,
						(error: ResponseError<void>) => {
							return client.handleFailedRequest(RenameRequest.type, token, error, null, false);
						}
					);
				};
				const middleware = client.clientOptions.middleware!;
				return middleware.provideRenameEdits
					? middleware.provideRenameEdits(document, position, newName, token, provideRenameEdits)
					: provideRenameEdits(document, position, newName, token);
			},
			prepareRename: options.prepareProvider
				? (document, position, token) => {
					if ($DocumentSelector.skipCellTextDocument(selector, document)) {
						return undefined;
					}
					const client = this._client;
					const prepareRename: PrepareRenameSignature = (document, position, token) => {
						let params: TextDocumentPositionParams = {
							textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(document),
							position: client.code2ProtocolConverter.asPosition(position),
						};
						return client.sendRequest(PrepareRenameRequest.type, params, token).then((result) => {
							if (Range.is(result)) {
								return client.protocol2CodeConverter.asRange(result);
							} else if (this.isDefaultBehavior(result)) {
								return result.defaultBehavior === true
									? null
									: Promise.reject(new Error(`The element can't be renamed.`));
							} else if (result && Range.is(result.range)) {
								return {
									range: client.protocol2CodeConverter.asRange(result.range),
									placeholder: result.placeholder
								};
							}
							// To cancel the rename vscode API expects a rejected promise.
							return Promise.reject(new Error(`The element can't be renamed.`));
						},
						(error: ResponseError<void>) => {
							if (typeof error.message === 'string') {
								throw new Error(error.message);
							} else {
								throw new Error(`The element can't be renamed.`);
							}
						}
						);
					};
					const middleware = client.clientOptions.middleware!;
					return middleware.prepareRename
						? middleware.prepareRename(document, position, token, prepareRename)
						: prepareRename(document, position, token);
				}
				: undefined
		};
		return [Languages.registerRenameProvider($DocumentSelector.asTextDocumentFilters(selector), provider), provider];
	}