Excercises Sprint 2- querry String / Tally

Author: Della-Bella

Sprint-2/implement/querystring.js

@@ -1,13 +1,40 @@
+// function parseQueryString(queryString) {
+//   const queryParams = {};
+//   if (queryString.length === 0) {
+//     return queryParams;
+//   }
+//   const keyValuePairs = queryString.split("&");
+
+//   for (const pair of keyValuePairs) {
+//     const [key, value] = pair.split("=");
+//     queryParams[key] = value;
+//   }
+
+//   return queryParams;
+// }
+
+// module.exports = parseQueryString;
+
 function parseQueryString(queryString) {
   const queryParams = {};
-  if (queryString.length === 0) {
+
+  if (!queryString) {
     return queryParams;
   }
+
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
-    queryParams[key] = value;
+    const index = pair.indexOf("=");
+
+    if (index === -1) {
+      // key with no value
+      queryParams[pair] = "";
+    } else {
+      const key = pair.slice(0, index);
+      const value = pair.slice(index + 1);
+      queryParams[key] = value;
+    }
   }
 
   return queryParams;

Sprint-2/implement/querystring.test.js

@@ -3,10 +3,39 @@
 // Below is one test case for an edge case the implementation doesn't handle well.
 // Fix the implementation for this test, and try to think of as many other edge cases as possible - write tests and fix those too.
 
-const parseQueryString = require("./querystring.js")
+const parseQueryString = require("./querystring.js");
 
-test("parses querystring values containing =", () => {
-  expect(parseQueryString("equation=x=y+1")).toEqual({
-    "equation": "x=y+1",
-  });
+// Empty string
+test("empty string", () => {
+  expect(parseQueryString("")).toEqual({});
 });
+// Single value
+test("single key-value", () => {
+  expect(parseQueryString("name=alice")).toEqual({ name: "alice" });
+});
+
+// Multiple pairs
+test("multiple pairs", () => {
+  expect(parseQueryString("a=1&b=2")).toEqual({ a: "1", b: "2" });
+});
+
+// Key with no value
+test("key with no value", () => {
+  expect(parseQueryString("flag")).toEqual({ flag: "" });
+});
+
+// Empty value
+test("empty value", () => {
+  expect(parseQueryString("name=")).toEqual({ name: "" });
+});
+
+// Multiple '=' in value
+test("values with multiple =", () => {
+  expect(parseQueryString("equation=x=y+1")).toEqual({ equation: "x=y+1" });
+});
+
+// Special characters
+test("special characters", () => {
+  expect(parseQueryString("msg=hello%20world")).toEqual({ msg: "hello%20world" });
+});
+

Sprint-2/implement/tally.js

@@ -1,3 +1,26 @@
-function tally() {}
+function tally(arr) {
+  // Handle invalid input
+  if (!Array.isArray(arr)) {
+    throw new Error("Input must be an array");
+  }
+
+  // Handle empty array
+  if (arr.length === 0) {
+    return {};
+  }
+
+  // Count frequencies
+  const result = {};
+
+  for (const item of arr) {
+    if (result[item]) {
+      result[item]++;
+    } else {
+      result[item] = 1;
+    }
+  }
+
+  return result;
+}
 
 module.exports = tally;

Sprint-2/implement/tally.test.js

@@ -1,5 +1,30 @@
 const tally = require("./tally.js");
 
+// Test 1: Empty array
+test("tally on an empty array returns an empty object", () => {
+  expect(tally([])).toEqual({});
+});
+
+// Test 2: Single item
+test("tally on single item returns count of 1", () => {
+  expect(tally(["a"])).toEqual({ a: 1 });
+});
+
+// Test 3: Duplicate items
+test("tally counts duplicate items", () => {
+  expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
+});
+
+// Test 4: Mixed items
+test("tally counts multiple unique items", () => {
+  expect(tally(["a", "a", "b", "c"])).toEqual({ a: 2, b: 1, c: 1 });
+});
+
+// Test 5: Invalid input throws error
+test("tally throws error for non-array input", () => {
+  expect(() => tally("hello")).toThrow();
+});
+
 /**
  * tally array
  *
@@ -23,7 +48,7 @@ const tally = require("./tally.js");
 // Given an empty array
 // When passed to tally
 // Then it should return an empty object
-test.todo("tally on an empty array returns an empty object");
+
 
 // Given an array with duplicate items
 // When passed to tally

package.json

@@ -0,0 +1,20 @@
+{
+  "name": "module-data-groups",
+  "version": "1.0.0",
+  "description": "Like learning a musical instrument, programming requires daily practice.",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/Della-Bella/Module-Data-Groups-Old.git"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/Della-Bella/Module-Data-Groups-Old/issues"
+  },
+  "homepage": "https://github.com/Della-Bella/Module-Data-Groups-Old#readme"
+}