String

import { capitalize } from "koyojs";

capitalize("hello world");  // "Hello world"
capitalize("javaScript");   // "JavaScript"
capitalize("");             // ""

// Note: only the very first character is changed — the rest stays as-is
capitalize("hELLO");  // "HELLO"

// Common use: format a user's display name from a form field
const name = capitalize(user.firstName.trim());

import { toCamelCase } from "koyojs";

toCamelCase("hello world");     // "helloWorld"
toCamelCase("my-variable");     // "myVariable"
toCamelCase("some_prop_name");  // "somePropName"
toCamelCase("--weird  input_"); // "weirdInput"

// Transform snake_case API response keys to camelCase for JS
const apiResponse = { user_id: 1, first_name: "Alice", is_admin: false };

const camel = Object.fromEntries(
  Object.entries(apiResponse).map(([k, v]) => [toCamelCase(k), v])
);
// { userId: 1, firstName: "Alice", isAdmin: false }

import { toSnakeCase } from "koyojs";

toSnakeCase("Hello World");   // "hello_world"
toSnakeCase("myVariable");    // "my_variable"
toSnakeCase("camelCaseKey");  // "camel_case_key"
toSnakeCase("already_snake"); // "already_snake"

// Serialize JS camelCase keys to snake_case for a REST API payload
const body = { firstName: "Alice", maxResults: 10, includeDeleted: false };

const snakeBody = Object.fromEntries(
  Object.entries(body).map(([k, v]) => [toSnakeCase(k), v])
);
// { first_name: "Alice", max_results: 10, include_deleted: false }

import { toTitleCase } from "koyojs";

toTitleCase("hello world");          // "Hello World"
toTitleCase("the quick brown fox");  // "The Quick Brown Fox"
toTitleCase("already Title Case");   // "Already Title Case"

// Render a blog post title stored in lowercase
const post = { title: "getting started with solidjs and vite" };
<h1>{toTitleCase(post.title)}</h1>
// "Getting Started With Solidjs And Vite"

// Format category labels coming from a database
const category = "science_and_technology";
toTitleCase(category.replace(/_/g, " "));
// "Science And Technology"

import { slugify } from "koyojs";

slugify("Hello World!");           // "hello-world"
slugify("My Blog Post Title #1");  // "my-blog-post-title-1"
slugify("  extra   spaces  ");     // "extra-spaces"
slugify("Déjà vu!");               // "deja-vu"

// Generate a permalink from a post title
const post = { title: "10 Tips for Writing Clean TypeScript" };
const url = `/blog/${slugify(post.title)}`;
// "/blog/10-tips-for-writing-clean-typescript"

// Build a URL-safe product ID
const product = { name: "Wireless Headphones Pro (2025 Edition)" };
const path = `/products/${slugify(product.name)}`;
// "/products/wireless-headphones-pro-2025-edition"

import { truncate } from "koyojs";

truncate("Hello, World!", 8);  // "Hello, W"
truncate("Short", 10);         // "Short"  — already fits, returned as-is
truncate("", 5);               // ""

// Enforce a database column length before INSERT
const bio = "This is a very long biography that goes on and on...";
const stored = truncate(bio, 255);

// Fit a string into a fixed-width terminal column
const label = truncate(filename, 20).padEnd(20);

import { ellipsify } from "koyojs";

ellipsify("A longer sentence here", 12);  // "A longer ..."
ellipsify("Short", 10);                   // "Short"  — fits, no ellipsis added
ellipsify("Hello World", 8);              // "Hello..."

// "..." is 3 chars, so visible text = length - 3
ellipsify("1234567890", 7);  // "1234..."

// Card description preview — limit to 80 characters
const card = { desc: "This product has many remarkable features worth exploring in depth." };
const preview = ellipsify(card.desc, 80);

// Notification message in a toast
const msg = ellipsify(errorMessage, 60);

import { isEmail } from "koyojs";

isEmail("user@example.com");      // true
isEmail("user+tag@domain.co.uk"); // true
isEmail("not-an-email");          // false
isEmail("@domain.com");           // false
isEmail("a@b");                   // false
isEmail("");                      // false

// Form validation before submitting
function handleSubmit(formData: { email: string }) {
  if (!isEmail(formData.email)) {
    setError("Please enter a valid email address.");
    return;
  }
  submitForm(formData);
}

// Filter out invalid emails from an import list
const validEmails = rawList.filter(isEmail);

import { isURL } from "koyojs";

isURL("https://example.com");            // true
isURL("http://localhost:3000");          // true
isURL("https://sub.domain.io/path?q=1"); // true
isURL("ftp://files.io/x");              // false — only http/https
isURL("//example.com");                 // false — must include protocol
isURL("not a url");                     // false

// Validate a user-submitted website link before storing
function saveProfile(data: { website: string }) {
  if (data.website && !isURL(data.website)) {
    throw new Error("Website must be a valid http/https URL");
  }
  db.save(data);
}

// Render a clickable link only when the value is a real URL
const href = isURL(user.website) ? user.website : null;

import { isPhoneNumber } from "koyojs";

isPhoneNumber("+1 (555) 123-4567");  // true
isPhoneNumber("+44 20 7946 0958");   // true
isPhoneNumber("555-123-4567");       // true
isPhoneNumber("5551234567");         // true
isPhoneNumber("123");                // false — too short
isPhoneNumber("abc");                // false

// Contact form validation
function validateContact(form: { phone: string }) {
  if (form.phone && !isPhoneNumber(form.phone)) {
    return "Enter a valid phone number (e.g. +1 555 123-4567)";
  }
}