TypeScript training - module 2 sample

index.ts

// sample shopping cart data
const shopping_cart = {
    items: [
        { id: '1', name: 'T-Shirt Game of Thrones', size: 'XL', taxCode: 'IVA23', quantity: 1, unitPrice: 24.99 },
        { id: '2', name: 'T-Shirt Big Bang Theory', size: 'L', taxCode: 'IVA23', quantity: 2, unitPrice: 12.50 },
    ],
    subTotal: 0,
    tax: 0,
    total: 0,
};

function getTaxRate(tax_code) {
    switch (tax_code) {
        case 'IVA13':
            return 0.13;
        case 'IVA6':
            return 0.06;
        default:
            return 0.23;
    }
}

function calculateItemTotal(item) {
    return item.quantity * item.unitPrice;
}

function calculateTax(items) {
    if (Array.isArray(items)) {
        return items.reduce((tax, item) => tax + calculateTax(item), 0);
    }

    const itemTotal = calculateItemTotal(items);
    return itemTotal - itemTotal / (1 + getTaxRate(items.taxCode));
}

function calculateTotal(items) {
    return items.reduce((total, item) => total + calculateItemTotal(item), 0);
}

function calculateCartTotals(cart) {
    let tax = calculateTax(cart.items);
    let total = calculateTotal(cart.items);

    return {
        ...cart,
        subTotal: total - tax,
        tax,
        total,
    };
}

function repeatStringNumTimes(string, times) {
    let repeatedString = '';
    while(times > 0) {
        repeatedString += string;
        times--;
    }
    return repeatedString;
}

function pad (value , maxLength , fillString = ' ') {
    if (value.length >= maxLength) {
        return value;
    }

    const fillLen = maxLength - value.length;
    const timesToRepeat = Math.ceil(fillLen / fillString.length);
    const truncatedStringFiller = repeatStringNumTimes(fillString, timesToRepeat)
        .slice(0, fillLen);

    return value + truncatedStringFiller;
}

function printItemLine(item) {
    console.log(`${pad(item.name, 40)} | ${pad(item.quantity, 10)} | ${pad(item.unitPrice, 10)} | ${pad(calculateItemTotal(item), 10)}`);
}

function printShoppingCart(cart) {
    cart = calculateCartTotals(cart);

    console.log('');
    console.log('SHOPPING CART');
    console.log('');
    console.log(repeatStringNumTimes('-', 80));
    console.log(`${pad('ITEM', 40)} | ${pad('QTY', 10)} | ${pad('PRICE', 10)} | ${pad('TOTAL', 10)}`);
    console.log(repeatStringNumTimes('-', 80));
    cart.items.forEach(item => printItemLine(item));
    console.log(repeatStringNumTimes('-', 80));
    console.log(`${pad('', 56)}${pad('SUB-TOTAL', 13)}${pad(cart.subTotal, 10)}`);
    console.log(`${pad('', 56)}${pad('TAX', 13)}${pad(cart.tax, 10)}`);
    console.log(`${pad('', 56)}${pad('TOTAL', 13)}${pad(cart.total, 10)}`);
    console.log(repeatStringNumTimes('-', 80));
}

printShoppingCart(shopping_cart);

package.json

{
    "name": "sample2",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
        "build": "tsc",
        "build-watch": "tsc -w",
        "start": "node index.js"
    },
    "author": "",
    "license": "MIT",
    "devDependencies": {
        "tslint": "^5.8.0",
        "typescript": "^2.5.3"
    }
}

tsconfig.json

{
  "compilerOptions": {
    /* Basic Options */
    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', or 'ESNEXT'. */
    "module": "none",                     /* Specify module code generation: 'none', commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
    // "lib": [],                             /* Specify library files to be included in the compilation:  */
    // "allowJs": true,                       /* Allow javascript files to be compiled. */
    // "checkJs": true,                       /* Report errors in .js files. */
    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
    // "outFile": "./",                       /* Concatenate and emit output to single file. */
    // "outDir": "./",                        /* Redirect output structure to the directory. */
    // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    // "removeComments": true,                /* Do not emit comments to output. */
    // "noEmit": true,                        /* Do not emit outputs. */
    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */

    /* Strict Type-Checking Options */
    "strict": true                            /* Enable all strict type-checking options. */
    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,              /* Enable strict null checks. */
    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    // "noUnusedLocals": true,                /* Report errors on unused locals. */
    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */

    /* Module Resolution Options */
    // "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                       /* List of folders to include type definitions from. */
    // "types": [],                           /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */

    /* Source Map Options */
    // "sourceRoot": "./",                    /* Specify the location where debugger should locate TypeScript files instead of source locations. */
    // "mapRoot": "./",                       /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */

    /* Experimental Options */
    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
  }
}

tslint.json

{
    "defaultSeverity": "error",
    "extends": [
        "tslint:recommended"
    ],
    "jsRules": {},
    "rules": {
        "quotemark": [true, "single"],
        "object-literal-sort-keys": false
    },
    "rulesDirectory": []
}