refactored the contains and tally functions to pass the test cases

Author: Ebrahim-Moqbel

Sprint-2/implement/contains.js

@@ -1,12 +1,16 @@
-function contains(object,result) {
-    for(const key in object){
-        if(key===result){
-            return true
-        }
+function contains(object, result) {
+  const isPlainObject =
+    typeof object === "object" && object !== null && !Array.isArray(object);
 
+  if (!isPlainObject) {
+    throw new Error("contains require an object");
+  }
+  for (const key in object) {
+    if (key === result) {
+      return true;
     }
-     return false
+  }
+  return false;
 }
 
-
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -23,31 +23,34 @@ as an array isn't an object
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test("contains on empty object returns false",()=>{
-    expect(contains({})).toEqual(false);
+test("contains on empty object returns false", () => {
+  expect(contains({})).toEqual(false);
 });
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
-test('contains passed an object and a property name, returns true',()=>{
-    expect(contains({a:1,b:2},"a")).toEqual(true);
+test("contains passed an object and a property name, returns true", () => {
+  expect(contains({ a: 1, b: 2 }, "a")).toEqual(true);
 });
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
-test('Contains passed with a non-existent property name, returns false',()=>{
-    expect(contains({a:1,b:2},"c")).toEqual(false);
+test("Contains passed with a non-existent property name, returns false", () => {
+  expect(contains({ a: 1, b: 2 }, "c")).toEqual(false);
 });
 
-
 // Given a value that isn't an object - an array, a string, a number,
 // null, or no argument at all
 // When passed to contains
 // Then it should throw Error("contains requires an object")
 // (careful: typeof [] and typeof null are both "object")
-test('contains passed invalid input like an array, a string or a number will throw an error', ()=>{
-    expect(contains([5,"5",6],"a")).toThrow(new Error("contains require an object"));
-    expect(contains('Ebra','Ebra')).toThrow(new Error("contains require an object"));
-    expect(contains(1,1)).toThrow(new Error("contains require an object"));
+test("contains passed invalid input like an array, a string or a number will throw an error", () => {
+  expect(() => contains([5, "5", 6], "a")).toThrow(
+    new Error("contains require an object")
+  );
+  expect(() => contains("Ebra", "Ebra")).toThrow(
+    new Error("contains require an object")
+  );
+  expect(() => contains(1, 1)).toThrow(new Error("contains require an object"));
 });

Sprint-2/implement/tally.js

@@ -1,18 +1,13 @@
 function tally(array) {
-    
-    if (!Array.isArray(array)){
-        throw new TypeError('unexpected Array')
-    }
-    const charCount={};
-    
-    
-
-    for(const char of array){
-       charCount[char] = (charCount[char] || 0) + 1;
-    }
-    return charCount
-
-
+  if (!Array.isArray(array)) {
+    throw new TypeError("tally requires an array");
+  }
+  const charCount = {};
+
+  for (const char of array) {
+    charCount[char] = (charCount[char] || 0) + 1;
+  }
+  return charCount;
 }
 
 module.exports = tally;