lookup function and testing it

Author: Nataliia74

Sprint-2/implement/lookup.js

@@ -1,16 +1,38 @@
 function createLookup(arr) {
-  // const arr1 =
-  // const arr2 =
+  let object = {};
+
+  if (!Array.isArray(arr) || arr.length < 1) {
+    throw new Error(
+      "The array is not array or have length less than 2 values."
+    );
+  }
+
   for (let i = 0; i < arr.length; i++) {
-    let newArray = countryCurrencyPairs[i];
-    console.log(newArray);
+    // looping through an array to get arrays inside
+    // current an array. Using indexing.
+    const keyValuePair = arr[i];
+
+    if (!Array.isArray(keyValuePair) || keyValuePair.length !== 2) {
+      throw new Error(
+        "The arrays inside are not arrays or have length less than 2 values."
+      );
+    }
+
+    const country_code = keyValuePair[0]; // assigning properties names
+    const currency_code = keyValuePair[1];
+    if (typeof country_code !== "string" || typeof currency_code !== "string") {
+      throw new Error("The type of key-value pair is not string.");
+    }
+    object[country_code] = currency_code; // populate the empty created earlier object
   }
-  return newArray;
+  return object;
 }
 
 const countryCurrencyPairs = [
   ["US", "USD"],
   ["CA", "CAD"],
 ];
 const result = createLookup(countryCurrencyPairs);
+console.log(result);
+
 module.exports = createLookup;

Sprint-2/implement/lookup.test.js

@@ -1,6 +1,42 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
+describe("edge cases of the lookup function", () => {
+  test("creates a country currency code lookup for multiple codes", () => {
+    const currentOutput = createLookup([
+      ["country", "currency"],
+      ["country1", "currency1"],
+      ["country2", "currency2"],
+    ]);
+    const targetOutput = {
+      country: "currency",
+      country1: "currency1",
+      country2: "currency2",
+    };
+    expect(currentOutput).toStrictEqual(targetOutput);
+  });
+
+  test("creates a country currency code lookup for empty array", () => {
+    // const currentOutput = createLookup([]);
+    // const targetOutput =
+    expect(() => createLookup([])).toThrow(
+      "The array is not array or have length less than 2 values."
+    );
+  });
+
+  test("creates a country currency code lookup for array with wrong type key-value pairs", () => {
+    // const currentOutput = createLookup([
+    // [3, 2],
+    //  [3, 1],
+    // ]);
+    // const targetOutput = "The type of key-value pair is not string.";
+    expect(() =>
+      createLookup([
+        [3, 2],
+        [3, 1],
+      ])
+    ).toThrow("The type of key-value pair is not string.");
+  });
+});
 
 /*