commenting resolver and schema files

Author: alexchao26

server/address/addressSchema.js

@@ -60,5 +60,7 @@ const Address = `
  }
  `;
 
+// return a thunk so hoisting can handle unordered schema imports in the schema.js file
+
 // The address and base schemas are exported together because the address extends the base schema
 module.exports = () => [Address, Base];

server/cart/cartSchema.js

@@ -34,4 +34,5 @@ const Cart = `
  }
  `;
 
+// return a thunk so hoisting can handle unordered schema imports in the schema.js file
 module.exports = () => [Cart, Base];

server/order/orderResolver.js

@@ -37,7 +37,6 @@ module.exports = {
  // declare client outside of try block to enable calling release() in catch block
  let client;
  // wrapping all async in one try block
- // TODO: is there a better way to do this?
  try {
  // assign client to awaited returned value of invoking connect on psqlPool
  client = await context.psqlPool.connect();
@@ -55,7 +54,6 @@ module.exports = {
  // insert into orderProducts for each product
  return client.query(orderProductQuery, values)
  // still using then here because it allows for more specific error messaging and isn't too nested
- // TODO: is this even necessary?
  .then((orderProductData) => {
  console.log(orderProductData.rows);
  })
@@ -75,6 +73,8 @@ module.exports = {
  return null;
  },
  },
+
+ // type resolver for nested types: Customer and Products
  Order: {
  customer: (parent, args, context) => {
  const query = 'SELECT * FROM customers WHERE id = $1 LIMIT 1';

server/order/orderSchema.js

@@ -38,4 +38,5 @@ const Order = `
  }
 `;
 
+// return a thunk so hoisting can handle unordered schema imports in the schema.js file
 module.exports = () => [Order, Customer, Product, Base];

server/product/productResolver.js

@@ -6,14 +6,19 @@
 
 module.exports = {
  Query: {
+ // query for a single product from the database by productId
  product: (parent, args, context) => {
+ // create the query and values arguments that are needed for the psql query
  const query = 'SELECT * FROM products WHERE "productId"=$1 LIMIT 1';
  const values = [args.productId];
 
+ // query the database and return a promise (graphql handles promises by resolvnig them and
+ // using the default resolver to match up key:value pairs as the final response)
  return context.psqlPool.query(query, values)
  .then((data) => data.rows[0])
  .catch((err) => console.log('ERROR LOOKING UP PRODUCT', err));
  },
+ // query for all products in the database
  products: (parent, args, context) => {
  const query = 'SELECT * FROM products';
 
@@ -23,6 +28,7 @@ module.exports = {
  },
  },
  Mutation: {
+ // mutation to add a product to the database
  addProduct: (parent, args, context) => {
  const query = 'INSERT INTO products (name, description, price, weight) VALUES ($1, $2, $3, $4) RETURNING *';
  const values = [args.name, args.description, args.price, args.weight];
@@ -36,6 +42,7 @@ module.exports = {
  .catch((err) => console.log('ERROR INSERTING PRODUCT', err)))
  .catch((err) => console.log('ERROR CONNECTING WHILE ADDING PRODUCT', err));
  },
+ // mutation to update a product
  updateProduct: (parent, args, context) => {
  let query = 'UPDATE products SET ';
  const values = [args.productId];
@@ -61,6 +68,7 @@ module.exports = {
  .catch((err) => console.log('ERROR UPDATING PRODUCT', err)))
  .catch((err) => console.log('ERROR CONNECTING WHILE UPDATING PRODUCT', err));
  },
+ // mutation to delete a product
  deleteProduct: (parent, args, context) => {
  const query = 'DELETE FROM products WHERE "productId"=$1 RETURNING *';
  const values = [args.productId];

server/product/productSchema.js

@@ -50,4 +50,5 @@ const Product = `
  }
 `;
 
+// return a thunk so hoisting can handle unordered schema imports in the schema.js file
 module.exports = () => [Product, Base];

server/resolvers.js

@@ -46,8 +46,8 @@ const {
  Mutation: CartMutation,
 } = require('./cart/cartResolver');
 
-// export all of those combined (Query and Mutation are standard & build into gql, Customer
-// is a type resolver)
+// export all of those combined (Query and Mutation are standard & built into GraphQL,
+//  Customer, Order and Warehouse are type resolvers)
 module.exports = {
  Query: {
  ...CustomerQuery,

server/warehouse/warehouseResolver.js

@@ -6,13 +6,15 @@
 
 module.exports = {
  Query: {
+ // query to look up data on an individual warehouse
  warehouse: (parent, args, context) => {
  const query = 'SELECT * FROM warehouses WHERE "warehouseId" = $1 LIMIT 1';
  const values = [args.warehouseId];
  return context.psqlPool.query(query, values)
  .then((data) => data.rows[0])
  .catch((err) => console.log('ERROR LOOKING UP WAREHOUSE', err));
  },
+ // query to return data on all warehouses
  warehouses: (parent, args, context) => {
  const query = 'SELECT * FROM warehouses';
  return context.psqlPool.query(query)
@@ -21,6 +23,7 @@ module.exports = {
  },
  },
  Mutation: {
+ // mutation to add a warehouse to the database
  addWarehouse: (parent, args, context) => {
  const query = 'INSERT INTO warehouses (name, "addressId") VALUES ($1, $2) RETURNING *';
  const values = [args.name, args.addressId];
@@ -34,6 +37,7 @@ module.exports = {
  .catch((err) => console.log('ERROR INSERTING WAREHOUSE', err)))
  .catch((err) => console.log('ERROR CONNECTING WHILE ADDING WAREHOUSE', err));
  },
+ // mutation to update details of a warehouse
  updateWarehouse: (parent, args, context) => {
  let query = 'UPDATE warehouses SET ';
  const values = [args.warehouseId];
@@ -59,6 +63,7 @@ module.exports = {
  .catch((err) => console.log('ERROR UPDATING WAREHOUSE', err)))
  .catch((err) => console.log('ERROR CONNECTING WHILE UPDATING WAREHOUSE', err));
  },
+ // mutation to delete a warehouse from the database
  deleteWarehouse: (parent, args, context) => {
  const query = 'DELETE FROM warehouses WHERE "warehouseId"=$1 RETURNING *';
  const values = [args.warehouseId];
@@ -73,6 +78,8 @@ module.exports = {
  .catch((err) => console.log('ERROR CONNECTING WHILE DELETING WAREHOUSE', err));
  },
  },
+
+ // type resolver for nested type: Address
  Warehouse: {
  address: (parent, args, context) => {
  const query = 'SELECT * FROM addresses WHERE id=$1 LIMIT 1';