CODEWITHSUNDEEP
javascriptnode.jsasynchronous
jsdev17
jsdev17

Reputation: 1110

async/await, data fetching, and unresolved promises

I'm running into an issue in an nodejs application I'm working on and can't seem to find a solution.

I'm working with the GitHub API to:

  1. Fetch repositories from a given user
  2. Fetch issues of every retrieved repository
  3. Bringing the data together into one "repo" object

Step 3 is where problems arise. I'm working with two async functions,getReposForUser() and getIssuesForRepo(), which behave as follows

async function getReposForUser(username) {
    // Fetch user repos from GitHub
    var result = await github.repos.getForUser({
        username: username,
        per_page: 100
    })
    // Grab issues for each repo
    repos = repos.map(repo => {
        return getIssuesForRepo(repo);
    });
    // console.log(repos);
 }


async function getIssuesForRepo(repo) {
/* 
    if there are issues available, fetch them and attach
    them to the repo object (under a property named issues).
    otherwise, assign the issues property a value of null
*/
if (repo.has_issues) {
    let issues = await github.issues.getForRepo({
        owner: repo.owner.login,
        repo: repo.name,
        state: 'open'
    });
    repo.issues = issues;
    return repo;
} else {
     return repo.issues = null;
    }
}

When I try to console.log(repos) after getIssuesForRepo() runs, I get an array of Promises. After doing some research, it's become clear that async/await functions return Promises. Ok, got that. My question is, what can I do in order to create a new array of objects with the resolved value of those promises? Basically, I want to attach the array of issues retrieved for each repo to its respective repo.

Thanks in advance to anyone who might help.

Also, why does this work inside getReposForUser() after getIssuesForRepo() runs?

let firsRepo = await getIssuesForRepo(repos[0]);
console.log(firsRepo);

In this case, I actually see the object, not the unresolved promise...

Upvotes: 1

Views: 722

Answers (1)

T.J. Crowder
T.J. Crowder

Reputation: 1075139

what can I do in order to create a new array of objects with the resolved value of those promises?

await Promise.all on the array of promises:

repos = await Promise.all(repos.map(repo => {
    return getIssuesForRepo(repo);
}));

Side note: Your map callback can just be getIssuesForRepo:

repos = await Promise.all(repos.map(getIssuesForRepo));

map calls its callback with the entry, its index, and the array being mapped. Since your getIssuesforRepo only uses its first argument, the extra two will be ignored.

Upvotes: 4

Related Questions