JS-0116 @ 37ecee9 • sisoe24 / Nuke-Tools

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5 months ago

37ecee9..37ecee9

27 s

async function should have await expression JS-0116

Bug risk

Minor

3 occurrences in this check

Found async function without any await expressions

src/socket.ts

170 * @param text - Stringified text to sent as code to be executed inside Nuke.
171 * @param timeout - time for the timeout connection. Defaults to 10000 ms (10sec).
172 */
173export async function sendData(174    host: string,175    port: number,176    text: string,177    timeout = 10000178): Promise<{ message: string; error: boolean; errorMessage: string }> {179    return new Promise((resolve, reject) => {180        const client = new Socket();181        const status = {182            message: "",183            error: false,184            errorMessage: "",185        };186187        logDebugNetwork(`Try connecting to ${host}:${port}`);188189        /**190         * Set connection timeout.191         *192         * Once emitted will close the socket with an error: 'connection timeout'.193         */194        client.setTimeout(timeout, () => {195            logDebugNetwork("Connection timeout.");196            client.destroy(new Error("Connection timeout"));197            reject(status);198        });199200        try {201            /**202             * Initiate a connection on a given socket.203             *204             * If host is undefined, will fallback to localhost.205             */206            client.connect(port, host, function () {207                logDebugNetwork("Connected.");208                client.write(text);209            });210        } catch (error) {211            if (error instanceof RangeError) {212                const msg = `Port is out of range. Value should be >= 49567 and < 65536. Received: ${port}`;213                logDebugNetwork(msg);214                client.destroy(new Error("Port out of range"));215                status.errorMessage = "Port is out of range";216            } else {217                const msg = `Unknown exception. ${String(error)}`;218                logDebugNetwork(msg);219                client.destroy(new Error(msg));220                status.errorMessage = msg;221            }222            status.error = true;223            reject(status);224        }225226        /**227         * Emitted when data is received.228         *229         * The argument data will be a Buffer or String. Encoding of data is set by socket.setEncoding().230         */231        client.on("data", function (data: string | Buffer) {232            const textData = data.toString();233234            const oneLineData = textData.replace(/\n/g, "\\n");235            logDebugNetwork(`Received: "${oneLineData}"\n`);236237            const filePath = JSON.parse(text)["file"];238            writeToOutputWindow(textData, filePath);239240            status.message = data.toString().trim();241            resolve(status);242            client.end();243        });244245        /**246         * Emitted after resolving the host name but before connecting.247         */248        client.on(249            "lookup",250            function (error: Error | null, address: string, family: string, host: string) {251                logDebugNetwork(252                    "Socket Lookup :: " +253                        JSON.stringify({ address, family, host, error }, null, " ")254                );255256                if (error) {257                    logDebugNetwork(`${error.message}`);258                    status.errorMessage = error.message;259                    reject(status);260                }261262            }263        );264265        /**266         * Emitted when an error occurs.267         *268         * The 'close' event will be called directly following this event.269         */270        client.on("error", function (error: Error) {271            const msg = `272            Couldn't connect to NukeServerSocket. Check the plugin and try again. 273            If manual connection is enable, verify that the port and host address are correct. 274            ${error.message}`;275            vscode.window.showErrorMessage(msg);276277            status.errorMessage = "Connection refused";278            status.error = true;279            reject(status);280        });281282        /**283         * Emitted when a socket is ready to be used.284         *285         * Triggered immediately after 'connect'.286         */287        client.on("ready", function () {288            logDebugNetwork("Message ready.");289        });290291        /**292         * Emitted once the socket is fully closed.293         */294        client.on("close", function (hadError: boolean) {295            logDebugNetwork(`Connection closed. Had Errors: ${hadError.toString()}`);296        });297298        /**299         * Emitted when the other end of the socket signals the end of transmission.300         */301        client.on("end", function () {302            logDebugNetwork("Connection ended.");303        });304305    });306}307
308/**
309 * Prepare a debug message to send to the socket.

Found async function without any await expressions

src/nuke/completitions.ts

22        return [];
23    }
24
25    private async getAllNodes(): Promise<vscode.CompletionItem[]> {26        return askNuke("[n.name() for n in nuke.allNodes()]").then((data) => {27            const nodes = JSON.parse(data.message.replace(/'/g, '"'));2829            const items: vscode.CompletionItem[] = [];30            for (const node of nodes) {31                items.push(new vscode.CompletionItem(`"${node}"`, vscode.CompletionItemKind.Class));32            }33            return items;34        });35    }36}

Found async function without any await expressions

src/nuke/completitions.ts

 2
 3import { sendCommand } from "../socket";
 4
 5async function askNuke(text: string) { 6    return sendCommand(JSON.stringify({ text: text, file: "" })); 7} 8
 9export class NukeCompletionProvider implements vscode.CompletionItemProvider {
10    provideCompletionItems(

Description

A function that does not contain any await expressions should not be async (except for some edge cases in TypeScript which are discussed below). Asynchronous functions in JavaScript behave differently than other functions in two important ways:

The return value is always a Promise.
You can use the await operator inside them.

Functions are made async so that we can use the await operator inside them. Consider this example:

async function fetchData(processDataItem) {
    const response = await fetch(DATA_URL);
    const data = await response.json();

    return data.map(processDataItem);
}

Asynchronous functions that don't use await might be an unintentional result of refactoring.

Note: This issue ignores async generator functions. Generators yield rather than return a value and async generators might yield all the values of another async generator without ever actually needing to use await.

In TypeScript, one might feel the need to make a function async to comply with type signatures defined by an interface. Ideally, the code should be refactored to get rid of such restrictions, but sometimes that isn't feasible (For example, when we are implementing an interface defined in a 3rd party library like Next.js).

This situation can easily be circumvented by returning the value with a call to Promise.resolve:

interface HasAsyncFunc {
  getNum: () => Promise<number>
}

// Not recommended:
const o: HasAsyncFunc = {
  async getNum() { return 1 }
}

// Recommended:
const o: HasAsyncFunc = {
  // We only use `Promise.resolve` to adhere to the type
  // of the surrounding object.
  getNum() { return Promise.resolve(1) }
}

It is also advised to add a comment near the redundant promise to make the intent clear.

Bad Practice

async function fetchData(): string {
    // `readFileSync` is a synchronous function that blocks
    // the main thread, and thus does not need to be `await`ed
    return fs.readFileSync("data.txt", "utf-8");
}

performAction(async () => { console.log("no awaits in here") });