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Prevent unfulfilled promises on sendCommand method #22

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Prevent unfulfilled promises on sendCommand method #22

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f847e2f
Prevent unfulfilled promises on sendCommand method
Mar 2, 2020
3c77956
PR adjust
Mar 12, 2020
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19 changes: 9 additions & 10 deletions src/Client.js
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Original file line number Diff line number Diff line change
Expand Up @@ -275,27 +275,26 @@ export default class Client {

// sendCommand :: Command -> Number -> Promise Command
sendCommand(command, timeout = this._application.commandTimeout) {
var commandPromise = Promise.race([
const commandPromise = Promise.race([
new Promise((resolve, reject) => {
this._commandResolves[command.id] = (c) => {
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To prevent a memory leak caused by an error in this function execution, you can design it in that way:

() => {
    try {
        // logic here
    } catch (err) {
        return reject(...);
    } finally {
        delete this._commandResolves[command.id];
    }
}

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We actually need a race of 2 promises here, because the command must fail if there was no response before the timeout

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I didn't question that. I'm talking about the arrow function you pass on the first promise.

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The try/catch block is a good way to prevent unhandled errors. By the way, it might help us to handle exceptions better at BLiP Portal

if (!c.status)
return;

if (c.status === Lime.CommandStatus.SUCCESS) {
if (!c.status){
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reject(new ClientError('Command received without a status'));
} else if (c.status === Lime.CommandStatus.SUCCESS) {
resolve(c);
}
else {
} else {
const cmd = JSON.stringify(c);
reject(new ClientError(cmd));
}

delete this._commandResolves[command.id];
};
}),
new Promise((_, reject) => {
new Promise((resolve, reject) => {
setTimeout(() => {
if (!this._commandResolves[command.id])
return;
if (!this._commandResolves[command.id]) {
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Why do you need to check it?

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I just added the bracket, but this if is used to guarantee the promise will only be reject for commands with timeout

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That if statement seems to be impossible to be true.

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@ceifa ceifa Mar 13, 2020 •
edited
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But anyway, I don't think that returning a string can be a good thing, think that consumers are expecting a specific type, in the case a lime envelope, returning a different type can cause problems. Miss you, typescript :(

resolve('Command already resolved');
}

delete this._commandResolves[command.id];
command.status = 'failure';
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