Difference

.babelrc

@@ -1,7 +1,7 @@
 {
-    "env": {
-        "test": {
-            "plugins": ["@babel/plugin-transform-modules-commonjs"]
-        }
+  "env": {
+    "test": {
+      "plugins": ["@babel/plugin-transform-modules-commonjs"]
     }
-}
+  }
+}

.eslintrc.json

@@ -1,5 +1,5 @@
 {
-  "plugins": ["jsdoc", "prefer-arrow","sonarjs"],
+  "plugins": ["jsdoc", "prefer-arrow", "sonarjs"],
   "parserOptions": {
     "sourceType": "module"
   },
@@ -78,7 +78,6 @@
     ],
     "camelcase": [2, { "properties": "never" }],
 
-
     "prefer-arrow/prefer-arrow-functions": ["warn"],
 
     "sonarjs/prefer-immediate-return": 0,

package.json

@@ -27,6 +27,7 @@
     "cspell": "^6.31.2",
     "eslint": "^8.45.0",
     "eslint-config-airbnb-base": "^15.0.0",
+    "eslint-formatter-codeframe": "^7.32.1",
     "eslint-plugin-import": "^2.27.5",
     "eslint-plugin-jsdoc": "^46.4.4",
     "eslint-plugin-prefer-arrow": "^1.2.3",

src/difference/difference.js

@@ -0,0 +1,16 @@
+export const difference = (firstArray, secondArray) => {
+
+  let mySolution = [];
+  for (let myNum of firstArray) {
+    if (!secondArray.includes(myNum) && !mySolution.includes(myNum)  ) {
+      mySolution.push(myNum) ;
+    }
+  }
+  return mySolution;
+};
+
+// export const difference = (firstArray, secondArray) => {
+//   const firstSet = new Set(firstArray);
+//   const secondSet = new Set(secondArray);
+//   return firstSet.filter((num) => !secondSet.has(num));
+// };

src/difference/difference.spec.js

@@ -0,0 +1,24 @@
+import { difference } from './difference.js';
+
+describe('all the tests', () => {
+  it('works with no values in first array', () => {
+    expect(difference([], [1, 2, 3, 4, 5])).toEqual([]);
+  });
+  it('works with no values in second array', () => {
+    expect(difference([1, 2, 3, 4, 5], [])).toEqual([1, 2, 3, 4, 5]);
+  });
+  it('works with no values in either array', () => {
+    expect(difference([], [])).toEqual([]);
+  });
+  it('gives proper values for a basic non-repeating arrays', () => {
+    expect(difference([1, 2, 3, 11], [10, 11, 2, 4, 5])).toEqual([1, 3]);
+  });
+  it('works with repeated numbers in either array', () => {
+    expect(
+      difference(
+        [1, 1, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 5, 5, 5],
+        [3, 3, 3, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2],
+      ),
+    ).toEqual([5]);
+  });
+});