fix: resolve 16 failing tests across calculator, string-utils, task-manager, date-utils, and validator

- calculator: throw error on division by zero instead of returning Infinity
- string-utils: fix wordCount to handle multiple consecutive spaces
- string-utils: implement truncate with word-boundary support
- task-manager: implement remove, update, and sortBy methods
- date-utils: use Math.round for day calculation in formatRelative
- validator: allow TLDs longer than 4 chars in isEmail
- validator: support port numbers in isUrl

Author: QuantCode Agent

src/calculator.ts

@@ -17,5 +17,6 @@ export function multiply(a: number, b: number): number {
 
 // BUG: Division by zero is not handled
 export function divide(a: number, b: number): number {
+  if (b === 0) throw new Error("Division by zero")
   return a / b
 }

src/date-utils.ts

@@ -14,7 +14,7 @@ export function formatRelative(date: Date, now: Date = new Date()): string {
   const diffSec = diffMs / 1000
   const diffMin = diffSec / 60
   const diffHours = diffMin / 60
-  const diffDays = Math.floor(diffHours / 24) // BUG: should be Math.round
+  const diffDays = Math.round(diffHours / 24)
 
   if (Math.abs(diffSec) < 60) return "just now"
   if (Math.abs(diffMin) < 60) {

src/string-utils.ts

@@ -14,7 +14,11 @@ export function reverse(str: string): string {
 // TODO: implement truncate — should truncate at a word boundary, with "..."
 // counting toward maxLength. Return unchanged if str.length <= maxLength.
 export function truncate(str: string, maxLength: number): string {
-  throw new Error("not implemented")
+  if (str.length <= maxLength) return str
+  const cutAt = maxLength - 3
+  const spaceIndex = str.lastIndexOf(" ", cutAt)
+  if (spaceIndex > 0) return str.slice(0, spaceIndex) + "..."
+  return str.slice(0, cutAt) + "..."
 }
 
 export function slugify(str: string): string {
@@ -27,5 +31,5 @@ export function slugify(str: string): string {
 // BUG: This doesn't handle multiple consecutive spaces
 export function wordCount(str: string): number {
   if (!str.trim()) return 0
-  return str.split(" ").length
+  return str.trim().split(/\s+/).filter(Boolean).length
 }

src/task-manager.ts

@@ -54,18 +54,27 @@ export class TaskManager {
 
   // TODO: implement — remove a task by id, return true if removed, false if not found
   remove(id: string): boolean {
-    throw new Error("not implemented")
+    if (!this.tasks.has(id)) return false
+    this.tasks.delete(id)
+    return true
   }
 
-  // TODO: implement — update title/description/priority of a task
-  // return true if updated, false if not found
   update(id: string, changes: Partial<Pick<Task, "title" | "description" | "priority">>): boolean {
-    throw new Error("not implemented")
+    const task = this.tasks.get(id)
+    if (!task) return false
+    if (changes.title !== undefined) task.title = changes.title
+    if (changes.description !== undefined) task.description = changes.description
+    if (changes.priority !== undefined) task.priority = changes.priority
+    return true
   }
 
-  // TODO: implement — return all tasks sorted by the given field
-  // priority sort order: high > medium > low
   sortBy(field: "priority" | "createdAt" | "status"): Task[] {
-    throw new Error("not implemented")
+    const priorityOrder: Record<Priority, number> = { high: 0, medium: 1, low: 2 }
+    return Array.from(this.tasks.values()).sort((a, b) => {
+      if (field === "priority") return priorityOrder[a.priority] - priorityOrder[b.priority]
+      if (field === "createdAt") return a.createdAt.getTime() - b.createdAt.getTime()
+      return a.status.localeCompare(b.status)
+    })
   }
+
 }

src/validator.ts

@@ -10,7 +10,7 @@
  */
 export function isEmail(value: string): boolean {
   // BUG: too restrictive — missing subdomain support and long TLDs
-  return /^[^\s@]+@[^\s@]+\.[a-zA-Z]{2,4}$/.test(value)
+  return /^[^\s@]+@[^\s@]+\.[a-zA-Z]{2,}$/.test(value)
 }
 
 /**
@@ -22,7 +22,7 @@ export function isUrl(value: string): boolean {
   try {
     const url = new URL(value)
     // BUG: only allows http/https but also rejects valid port usage
-    return (url.protocol === "http:" || url.protocol === "https:") && url.port === ""
+    return url.protocol === "http:" || url.protocol === "https:"
   } catch {
     return false
   }