Tasks for HigherOrderFunction

.eslintrc.json

@@ -18,7 +18,7 @@
     ],
     "linebreak-style": [
       "error",
-      "unix"
+      "windows"
     ],
     "quotes": [
       "error",

Exercises/1-callback.js

@@ -1,5 +1,10 @@
 'use strict';
 
-const iterate = (obj, callback) => null;
+const iterate = (obj, callback) => {
+  for (const field in obj) {
+    const value = obj[field];
+    callback(field, value, obj);
+  }
+};
 
 module.exports = { iterate };

Exercises/2-closure.js

@@ -1,5 +1,6 @@
 'use strict';
 
-const store = x => null;
+const store = x => () => x;
+
 
 module.exports = { store };

Exercises/3-wrapper.js

@@ -1,5 +1,21 @@
 'use strict';
 
-const contract = (fn, ...types) => null;
+const contract = (fn, ...types) => (...args) => {
+  for (let i = 0; i < types.length - 1; i++) {
+    const arg = args[i];
+    const type = types[i];
+    const name = type.name.toLowerCase();
+    if (typeof(arg) !== name) {
+      throw new TypeError(`Argument expected to be ${name}`);
+    }
+  }
+  const res = fn(...args);
+  const typeOfRes = types[types.length - 1];
+  const name = typeOfRes.name.toLowerCase();
+  if (typeof(res) !== name) {
+    throw new TypeError(`Result expected to be ${name}`);
+  }
+  return res;
+};
 
 module.exports = { contract };