How do I add recursive logic in resolvers using GraphQL mutations? - graphql

Question

Is it possible to add logic in resolvers using GraphQL mutations?
I am trying to create a four-digit string as an alias for a post if the user does not provide it. Then, I would like to check the database to see if the four-digit string exists. If the string exists, I would like to create another four-digit string recursively.
At the moment, I'm exploring adding logic to mutations within resolvers, but I'm not sure if this is doable. I'm using these documents for my foundation: graphql.org sequelize.org
This is my current code block:
Working as of 12/4/2020
const MakeSlug = require("./services/MakeSlug");
const resolvers = {
Query: {
async allLinks(root, args, { models }) {
return models.Link.findAll();
},
async link(root, { id }, { models }) {
return models.Link.findByPk(id);
}
},
Mutation: {
async createLink(root, { slug, description, link }, { models }) {
if (slug !== undefined) {
const foundSlug = await models.Link.findOne({
where: { slug: slug }
});
if (foundSlug === undefined) {
return await models.Link.create({
slug,
description,
link,
shortLink: `https://shink.com/${slug}`
});
} else {
throw new Error(slug + " exists. Try a new short description.");
}
}
if (slug === undefined) {
const MAX_ATTEMPTS = 10;
let attempts = 0;
while (attempts < MAX_ATTEMPTS) {
attempts++;
let madeSlug = MakeSlug(4);
const foundSlug = await models.Link.findOne({
where: { slug: madeSlug }
});
if (foundSlug !== undefined) {
return await models.Link.create({
slug: madeSlug,
description,
link,
shortLink: `https://shink.com/${madeSlug}`
});
}
}
throw new Error("Unable to generate unique alias.");
}
}
}
};
module.exports = resolvers;
This is my full codebase.
Thank you!

Answer 1

A while loop solved the challenge. Thanks xadm.
const MakeSlug = require("./services/MakeSlug");
const resolvers = {
Query: {
async allLinks(root, args, { models }) {
return models.Link.findAll();
},
async link(root, { id }, { models }) {
return models.Link.findByPk(id);
}
},
Mutation: {
async createLink(root, { slug, description, link }, { models }) {
if (slug !== undefined) {
const foundSlug = await models.Link.findOne({
where: { slug: slug }
});
if (foundSlug === undefined) {
return await models.Link.create({
slug,
description,
link,
shortLink: `https://shink.com/${slug}`
});
} else {
throw new Error(slug + " exists. Try a new short description.");
}
}
if (slug === undefined) {
const MAX_ATTEMPTS = 10;
let attempts = 0;
while (attempts < MAX_ATTEMPTS) {
attempts++;
let madeSlug = MakeSlug(4);
const foundSlug = await models.Link.findOne({
where: { slug: madeSlug }
});
if (foundSlug !== undefined) {
return await models.Link.create({
slug: madeSlug,
description,
link,
shortLink: `https://shink.com/${madeSlug}`
});
}
}
throw new Error("Unable to generate unique alias.");
}
}
}
};
module.exports = resolvers;