In the following code the Promise.reject
doesn't work unless I specifically use return Promise.reject(...)
. Why is this?
Promise.resolve('Promise 1 Done')
.then(function(result) {
console.log(result);
return 'Promise 2 Done'
}).then(function(result) {
let j;
try {
j = JSON.parse("invalid will throw");
console.log(j);
} catch(err) {
Promise.reject('Could not parse JSON');
}
console.log(result);
}).catch(function(err) {
console.log(err);
});
Promise.reject
creates a value, it does not throw an exception that breaks from the function like throw
does. If you don't return
that value, it will be ignored and the control flow continues.
Given you are inside a promise callback, you could (and possibly should) instead use
throw new Error('Could not parse JSON');
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