Function evaluateRequest

src/debug/dart_debug_impl.ts:1173–1272

(response: DebugProtocol.EvaluateResponse, args: DebugProtocol.EvaluateArguments)

	}

	protected async evaluateRequest(response: DebugProtocol.EvaluateResponse, args: DebugProtocol.EvaluateArguments): Promise<void> {
		const isClipboardContext = args.context === "clipboard";
		const isWatchContext = args.context === "watch";
		const expression: string = args.expression.replace(trailingSemicolonPattern, "");

		if (expression.endsWith(",nq") || expression.endsWith(",h") || expression.endsWith(",d")) {
			this.errorResponse(response, "Format specifiers are only supported in the SDK debug adapters");
			return;
		}

		// Stack frame scope; if not specified, the expression is evaluated in the global scope.
		const frameId = args.frameId;

		const data = frameId ? this.threadManager.getStoredData(frameId) : undefined;
		const thread = data ? data.thread : this.threadManager.threads[0];

		try {
			let result: DebuggerResult | undefined;
			if (!data) {
				if (!this.vmService || !thread) {
					this.errorResponse(response, "Global evaluation requires a thread to have been loaded");
					return;
				}

				const isolate = (await this.vmService.getIsolate(thread.ref.id)).result as VMIsolate;
				const rootLib = isolate.rootLib;

				if (!rootLib) {
					this.errorResponse(response, "global evaluation requires a rootLib on the initial thread");
					return;
				}

				// Don't wait more than a second for the response:
				//   1. VS Code's watch window behaves badly when there are incomplete evaluate requests
				//      https://github.com/Microsoft/vscode/issues/52317
				//   2. The VM sometimes doesn't respond to your requests at all
				//      https://github.com/flutter/flutter/issues/18595
				result = await this.withTimeout(this.vmService.evaluate(thread.ref.id, rootLib.id, expression, true));
			} else {
				const frame = data.data as VMFrame;
				if ((expression === threadExceptionExpression || expression.startsWith(`${threadExceptionExpression}.`)) && thread.exceptionReference) {
					const exceptionData = this.threadManager.getStoredData(thread.exceptionReference);
					const exceptionInstanceRef = exceptionData && exceptionData.data as VMInstanceRef;

					if (expression === threadExceptionExpression) {
						response.body = {
							result: await this.fullValueAsString(thread.ref, exceptionInstanceRef) || "<unknown>",
							variablesReference: thread.exceptionReference,
						};
						this.sendResponse(response);
						return;
					}

					const exceptionId = exceptionInstanceRef && exceptionInstanceRef.id;

					if (exceptionId)
						result = await this.vmService!.evaluate(thread.ref.id, exceptionId, expression.substr(threadExceptionExpression.length + 1), true);
				}