CODEWITHSUNDEEP
typescriptvisual-studio-codevscode-extensions
Mike
Mike

Reputation: 51

Extension command not handling promise reject

A rejected promise is not being handled by my VSCode extension.

Why doesn't the following extension show the error dialog when the command is run?

'use strict';
import {commands,window,ExtensionContext} from 'vscode';

export function activate(context: ExtensionContext) {
    let cmd = commands.registerCommand('extension.sayHello', sayHello)
    context.subscriptions.push(cmd);
}
function sayHello() {
    doSomethingAsync('hello')
    .then(  res => window.showInformationMessage('Success!') )
    .catch( err => window.showErrorMessage(err) )
}
function doSomethingAsync(value:string): Promise<string> {
    return new Promise <string> ( (resolve, reject) => {
        setTimeout(function() {
            reject(new Error('Rejected!'))            
        }, 250);
    });
}

Doing the same thing vanilla Typescript works as expected:

'use strict';
function sayHello() {
    doSomethingAsync('hello')
    .then(  res => console.log('Success!') )
    .catch( err => console.error('Failed!', err) )
}
function doSomethingAsync(value:string): Promise<string> {
    return new Promise <string> ( (resolve, reject) => {
        setTimeout(function() {
            reject(new Error('Rejected!'))    
        }, 250);
    });
}
sayHello()

Output:

$ node --version && tsc --version && code --version
v8.1.3
Version 2.3.4
1.13.1
379d2efb5539b09112c793d3d9a413017d736f89

$ ls ~/.vscode/extensions/

$ tsc -p ./ && node out/src/reject.js
Failed! Error: Rejected!
    at Timeout._onTimeout (/Users/mike/Source/vscode/extensions/issues/vscode-unhandled-promise/out/src/reject.js:9:20)
    at ontimeout (timers.js:488:11)
    at tryOnTimeout (timers.js:323:5)
    at Timer.listOnTimeout (timers.js:283:5)

Upvotes: 1

Views: 528

Answers (1)

Mike
Mike

Reputation: 51

The vscode team pointed out that window.showErrorMessage needs a string, not an Error. Changing to showErrorMessage(err.message) (or something a bit more robust) fixes the issue.

Upvotes: 1

Related Questions