Script language definitionPrivate preview

// Numeric values
let num: number = 42;
let pi: number = 3.14159;

// Strings
let greeting: string = "Hello, world!";
let multiline: string = `This is a
multi-line string`;

// Booleans
let active: boolean = true;
let completed: boolean = false;

// Null
let empty: null = null;

// Variable declarations
let count: number = 0;
let name: string = "John";

// Constants (must be initialized)
const PI: number = 3.14159;
const API_KEY: string = "abcd1234";

// Type inferred as number
let score = 100;

// Explicitly typed
let highScore: number = 0;

// Function declaration
function add(a: number, b: number): number {
  return a + b;
}

// Arrow function (lambda)
const multiply = (a: number, b: number): number => {
  return a * b;
};

// Inline arrow function
const double = (x: number): number => x * 2;

// Object literal
let person = {
  name: "Alice",
  age: 30,
  address: {
    city: "Wonderland",
    zipCode: "12345"
  }
};

// Array literal
let numbers = [1, 2, 3, 4, 5];
let names: string[] = ["Alice", "Bob", "Charlie"];

// Array spread
let moreNumbers = [...numbers, 6, 7, 8, 9, 10];

// Accessing properties
let cityName = person.address.city;
let firstNumber = numbers[0];

// If-else statement
if (score > 100) {
  console.log("High score!");
} else if (score > 50) {
  console.log("Good score!");
} else {
  console.log("Try again!");
}

// While loop
let i = 0;
while (i < 5) {
  console.log(i);
  i++;
}

// For loop
for (let j = 0; j < 5; j++) {
  console.log(j);
}

// Break in a loop
let i = 0;
while (true) {
  if (i >= 5) {
    break;
  }
  i++;
}

// Arithmetic operators
let sum = 5 + 3;
let difference = 10 - 4;
let product = 3 * 7;
let quotient = 20 / 4;
let remainder = 10 % 3;  // Modulo

// Comparison operators
let equal = (5 == 5);
let notEqual = (5 != 3);
let greater = (10 > 5);
let less = (5 < 10);
let greaterOrEqual = (5 >= 5);
let lessOrEqual = (4 <= 4);

// Logical operators
let and = (true && false);  // false
let or = (true || false);   // true
let not = !true;            // false

// Compound assignment
let value = 5;
value += 3;  // value is now 8

// Importing modules
import { DiscountableItem } from '@stripe/scripts/discounts';

// Export a function
export function calculateTotal(items: DiscountableItem[]): number {
  let sum = 0;
  for (let i = 0; i < items.length; i++) {
    sum += items[i].price;
  }
  return sum;
}

// Default export
export default function main() {
  // Main function logic
}

let count: number = 0;
let name: string = "John";
let active: boolean = true;
let items: string[] = ["apple", "banana"];

// Inline object type
let person: { name: string; age: number } = {
  name: "Alice",
  age: 30
};

// Interface definition
interface Product {
  id: string;
  name: string;
  price: number;
  inStock?: boolean;  // Optional property
}

// Using the interface
let laptop: Product = {
  id: "lt-001",
  name: "Laptop",
  price: 999.99,
  inStock: true
};

// Union type
let id: string | number;

id = "abc123";  // Valid
id = 123;       // Also valid

// Type alias
type ID = string | number;

// Using the type alias
let userId: ID = "user123";
let productId: ID = 456;

// Complex type declaration
type ApiResponse = {
  status: number;
  data: {
    items: any[];
    count: number;
  };
  error?: string;
};

// Guaranteed to terminate - marked as T
function countdown(n: number): void {
  while (n > 0) {
    n = n - 1;  // Decreasing counter
  }
}

// Not guaranteed to terminate - marked as U
function infinite(): void {
  while (true) {
    console.log("This runs forever");
  }
}

// Safe recursion - marked as T
function factorial(n: number): number {
  if (n <= 1) return 1;
  return n * factorial(n - 1);  // n decreases with each call
}

// Unsafe recursion - marked as U
function badRecursion(n: number): number {
  return badRecursion(n + 1);  // n increases, no termination
}

// Safe loop pattern - marked as T
for (let i = 0; i < array.length; i++) {
  // Loop body with terminating operations
}

// Safe while loop - marked as T
let counter = 10;
while (counter > 0) {
  // Do something
  counter--;  // Counter decreases
}

// Good pattern for loops
function processItems(items: any[]): void {
  for (let i = 0; i < items.length; i++) {
    processItem(items[i]);
  }
}

// Math operations
let min = Math.min(5, 3, 7);  // 3
let max = Math.max(5, 3, 7);  // 7
let floor = Math.floor(3.7);  // 3
let ceil = Math.ceil(3.2);    // 4

// Array creation
let numbers = [1, 2, 3, 4, 5];

// Array properties
let length = numbers.length;  // 5

// Array indexing
let firstItem = numbers[0];  // 1
let lastItem = numbers[numbers.length - 1];  // 5

// Array methods
let sorted = numbers.sort((a, b) => a - b);

// String concatenation
let firstName = "John";
let lastName = "Doe";
let fullName = firstName + " " + lastName;  // "John Doe"

// String with template literals
let greeting = `Hello, ${firstName}!`;  // "Hello, John!"

/**
 * Max Amount Percent Off Discount
 *
 * This discount function applies a percentage discount to the gross amount,
 * but caps the total discount at a maximum amount. It calculates the discount
 * as a percentage of the gross amount and then ensures it doesn't exceed the
 * configured maximum.
 *
 * Configuration:
 * - max_amount: The maximum monetary amount that can be discounted
 * - percent: The percentage discount to apply
 */
import { MonetaryAmount, Percent } from '@stripe/scripts';
import {
  DiscountFunction,
  DiscountableItem,
  DiscountResult,
} from '@stripe/scripts/discounts';

type Configuration = {
  max_amount: MonetaryAmount;
  percent: Percent;
};

const maxAmountPercentOff: DiscountFunction<Configuration> = (
  configuration: Configuration,
  item: DiscountableItem,
): DiscountResult => {
  const { max_amount, percent } = configuration;
  const discount_amount = Math.min(max_amount.amount, item.gross_amount.amount * (percent / 100));

  return {
    discount: {
      amount: {
        amount: discount_amount,
        currency: item.gross_amount.currency,
      },
      status: discount_amount > 0 ? 'APPLIED' : 'NOT_APPLIED',
      reason: discount_amount > 0 ? 'Discount applied' : 'No discount applied',
    },
    line_item_discounts: [],
  };
};

export default maxAmountPercentOff;

/**
 * Tiered Discount
 *
 * This discount function applies percentage discounts based on quantity tiers.
 * It sums the quantities across all line items and applies the discount percentage
 * from the highest applicable tier. The discount is calculated on each line item's
 * subtotal amount.
 *
 * Configuration:
 * - tiers: Array of objects with minimum_quantity and discount_percent
 *   The tiers are sorted by minimum_quantity in descending order to find
 *   the highest applicable tier.
 */
import {
  DiscountFunction,
  DiscountableItem,
  DiscountResult,
  ItemDiscount,
} from '@stripe/scripts/discounts';

type Configuration = {
  tiers: Array<{
    minimum_quantity: number;
    discount_percent: number;
  }>;
};

const tieredDiscount: DiscountFunction<Configuration> = (
  configuration: Configuration,
  item: DiscountableItem,
): DiscountResult => {
  let discountPercent = 0;
  let totalQuantity = 0;

  for (let i = 0; i < item.line_items.length; i++) {
    totalQuantity += item.line_items[i]?.quantity ?? 0;
  }

  const sortedTiers = [...configuration.tiers].sort(
    (a, b) => b.minimum_quantity - a.minimum_quantity,
  );

  for (let i = 0; i < sortedTiers.length; i++) {
    const tier = sortedTiers[i];
    if (totalQuantity >= tier.minimum_quantity) {
      discountPercent = tier.discount_percent;
      break; // Stop after finding the first applicable tier
    }
  }

  let totalDiscountAmount = 0;
  const lineItemDiscounts: ItemDiscount[] = [];

  for (let i = 0; i < item.line_items.length; i++) {
    const lineItem = item.line_items[i];
    const lineItemDiscount = lineItem.subtotal.amount * (discountPercent / 100);

    totalDiscountAmount += lineItemDiscount;

    lineItemDiscounts.push({
      discountable_item_id: lineItem.id,
      discount: {
        amount: {
          amount: lineItemDiscount,
          currency: lineItem.subtotal.currency,
        },
        status: lineItemDiscount > 0 ? 'APPLIED' : 'NOT_APPLIED',
        reason:
          lineItemDiscount > 0
            ? `${discountPercent}% tier discount applied`
            : 'No discount applied',
      },
    });
  }

  return {
    discount: {
      amount: {
        amount: totalDiscountAmount,
        currency: item.gross_amount.currency,
      },
      status: totalDiscountAmount > 0 ? 'APPLIED' : 'NOT_APPLIED',
      reason:
        totalDiscountAmount > 0
          ? `${discountPercent}% tier discount applied`
          : 'No discount applied',
    },
    line_item_discounts: lineItemDiscounts,
  };
};

export default tieredDiscount;