Solutions to promises exercises

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 *.log
+.DS_Store

README.md

@@ -1,4 +1,4 @@
-# JavaScript Exercises
+# JavaScript Exercises!!!
 
 Complete the exercises in this repo and push your solutions up to a branch (`firstname-lastname`).
 

exercise-4.js

@@ -13,7 +13,8 @@ const reduce = (array, fn, init) => {
   }
 
   // recursive case
-  return reduce(array.slice(1), fn, fn(init, array[0]));
+  // return reduce(array.slice(1), fn, fn(init, array[0])); // my way
+  return reduce(array, fn, fn(init, array.shift())); // another way
 };
 
 const sum = (acc, val) => acc + val;

package.json

@@ -20,5 +20,10 @@
   "homepage": "https://github.com/bridge-school/js-exercises#readme",
   "devDependencies": {
     "jest": "^22.1.4"
+  },
+  "main": "exercise-1.js",
+  "dependencies": {
+    "es6-promise": "^4.2.4",
+    "node-fetch": "^2.0.0"
   }
 }

promises/exercise-1.js

@@ -0,0 +1,16 @@
+require('es6-promise');
+
+// Create a promise. Have it fulfilled with a value of 'FULFILLED!' in executor after a delay of 300ms, using setTimeout.
+// Then, print the contents of the promise after it has been fulfilled by passing console.log to then.
+
+const promise = new Promise(function(resolve, reject) {
+  setTimeout(() => {
+    resolve('FULFILLED!');
+  }, 300);
+});
+
+const onResolve = data => {
+  console.log(data);
+};
+
+promise.then(onResolve);

promises/exercise-2.js

@@ -0,0 +1,21 @@
+require("es6-promise");
+
+// Create a promise that after a delay of 300ms, rejects with an Error object. The Error object should be constructed with parameter 'REJECTED!', which is the textual message of the error.
+// Create a function onReject to print error.message using console.log. Pass this function as a rejection handler to the then method of your promise.
+
+const promise = new Promise(function(resolve, reject) {
+  // Your solution here
+  setTimeout(() => {
+    reject(new Error('REJECTED!'));
+  }, 1000);
+});
+
+const onReject = value => {
+  // Your solution here
+  console.log(value.message);
+
+};
+
+promise.catch(
+  onReject
+);

promises/exercise-3.js

@@ -0,0 +1,10 @@
+const fetch = require('node-fetch');
+
+// Make a fetch request to https://next.json-generator.com/api/json/get/EJPkuFBIV
+
+fetch("https://next.json-generator.com/api/json/get/EJPkuFBIV")
+    .then((res) => res.json())
+    .then(response => {
+        response.map(item => console.log(item.first))
+    });
+

promises/exercise-4.js

@@ -0,0 +1,62 @@
+require("es6-promise");
+
+const listOfWines = [
+    {id: 'someId', name: 'Black Tower', type: 'White', num: 1},
+    {id: 'someOtherId', name: 'Merlot', type: 'Red', num: 2},
+    {id: 'somethingElse', name: 'Yellow Tail', type: 'Red', num: 3},
+];
+// const listOfWines = [];
+
+  /* 1. Create a promise. Have it fulfilled with the list of wines after a delay of 3000ms, using setTimeout.
+     2. Then, print the contents of the promise after it has been fulfilled by passing console.log to then.
+     3. Create a failedPromise that rejects with the error message 'something is broken' after a delay of 3000ms, using setTimeout
+     4. Then, using the contents of the promise after it returns, console.log the error message 'Oh no, the request failed becasuse' and append the error message;
+
+     Extra challenge:
+     A. Update the onSuccess function so that takes the returned wines, filters the list to only include the red wines and then print that list 
+     B. Refactor your code so that instead of seperate named callback functions 'onSuccess' and 'onReject', you write the functions inline */
+
+
+  const myPromise = new Promise((resolve, reject) => {
+    // Your solution for #1 here
+    if (listOfWines.length === 0) {
+      reject('something is broken')
+    } else {
+      setTimeout(() => {
+        resolve(listOfWines);
+      }, 3000);
+    }
+  });
+
+  const onSuccess = value => {
+    // Your solution here
+    const newlist = value.filter(thing => thing.type == 'Red');
+    console.log(newlist);
+  };
+
+  // Use myPromise here with onSuccess
+  myPromise
+  .then((data) => {
+    console.log(data.filter(thing => thing.type == 'Red'));
+  }).catch((err) => {
+    console.log('Oh no, the request failed becasuse', err)
+  });
+
+
+
+  // const myFailedPromise = new Promise((resolve, reject) => {
+  //   // Your solution for #3 here
+  //   setTimeout(() => {
+  //     reject('something is broken');
+  //   }, 3000);
+  // });
+
+  // const onReject = value => {
+  //   // Your solution here
+  //   console.log('Oh no, the request failed becasuse', value)
+  // };
+
+  // use myFailedPromise here with onReject
+  // myFailedPromise.catch((err) => {
+  //   onReject(err);
+  // });