added new tests

Author: HilolaRustam

Sprint-2/implement/lookup.test.js

@@ -3,15 +3,46 @@ const createLookup = require("./lookup.js");
 test("creates a country currency code lookup for multiple codes", () => {
   const input = [
     ['US', 'USD'],
-    ['CA', 'CAD']
+    ['CA', 'CAD'],
+    ['UK', 'GBP'],
   ];
   const expected = {
     US: 'USD',
-    CA: 'CAD'
+    CA: 'CAD',
+    UK: 'GBP'
   };
  expect(createLookup(input)).toEqual(expected);
 });
 
+test("returns an empty object when given an empty array", () => {
+  expect(createLookup([])).toEqual({});
+});
+
+test("overwrites value if a country code appears more than once", () => {
+  const input = [
+    ['UK', 'GBP'],
+    ['UK', 'POUND']
+  ];
+  expect(createLookup(input)).toEqual({ UK: 'POUND' });
+});
+
+test("ignores extra values in pairs", () => {
+  const input = [
+    ['UK', 'GBP', 'Extra'],
+    ['US', 'USD']
+  ];
+  expect(createLookup(input)).toEqual({ UK: 'GBP', US: 'USD' });
+});
+
+test("ignores invalid pairs (less than two elements)", () => {
+  const input = [
+    ['UK'], // Invalid
+    ['US', 'USD']
+  ];
+  expect(createLookup(input)).toEqual({ US: 'USD' });
+});
+
+
   /*
 
 Create a lookup object of key value pairs from an array of code pairs
@@ -20,7 +51,7 @@ Acceptance Criteria:
 
 Given
  - An array of arrays representing country code and currency code pairs
-   e.g. [['US', 'USD'], ['CA', 'CAD']]
+   e.g. [['US', 'USD'], ['CA', 'CAD'],['UK','GBP']]
 
 When
  - createLookup function is called with the country-currency array as an argument
@@ -31,7 +62,7 @@ Then
  - The values are the corresponding currency codes
 
 Example
-Given: [['US', 'USD'], ['CA', 'CAD']]
+Given: [['US', 'USD'], ['CA', 'CAD'], ['UK', 'GPB']]
 
 When
 createLookup(countryCurrencyPairs) is called
@@ -40,6 +71,7 @@ Then
 It should return:
  {
    'US': 'USD',
-   'CA': 'CAD'
+   'CA': 'CAD',
+   'UK': 'GBP'
  }
 */