geoperez / js-test

JS Test

js-test

JS Test

Syllabus

• Basics: Scopes, closures, this, bind, apply and types.
• Intermediate: promises, iterators, generators, async/await and template literals.
• Bonus: Proper use of objects and arrays and control flow.

Instructions

Create a SDK object with the following methods:

NOTE - You need to save all the logs in an internal data structure. You will need to provide previous logs with some methods.

• version() - Parameterless function returns 1.
• formatText(templateFn, data) - Function receiving a function and an data object:

function greet() {
    return `Hello ${this.name}`;
}

sdk.formatText(greet, { name: 'Juan' }); // 'Hello Juan'

• createLogger(templateFn, loggerName) - Function receiving a function and returning a new one with a line tracker:

function log() {
    return `Info: ${this.logMessage}`;
}

const logger = sdk.createLogger(log, 'Main');
logger( { logMessage: 'Init system' }); // '1 - Main - Info: Init system'
logger( { logMessage: 'Init userspace' }); // '2 - Main - Info: Init userspace'

• createLevelLogger(level) - Function returning a tagged template with a line tracker and expecting a loggerName variable:

const info = sdk.createLevelLogger('Info');
const loggerName = 'Main';
info`${loggerName} Init system`; // '1 - Info - Main: Init system'
info`${loggerName} Init userspace`; // '2 - Info - Main: Init userspace'

• createLoggerAsync(loggerName) - Function returning a promise of an object with a setter method setLoggerFn. If the loggerName is empty, reject the promise:

// Valid promise
function log() {
    return `Info: ${this.logMessage}`;
}

const logger = await sdk.createLoggerAsync('Main');
logger.setLoggerFn(log);
logger.log( { logMessage: 'Init system' }); // '1 - Main - Info: Init system'
logger.log( { logMessage: 'Init userspace' }); // '2 - Main - Info: Init userspace'

// Invalid promise
try {
    const invalidLogger = await sdk.createLoggerAsync();
} catch {
    // Throw
}

• getLogEntries(level) - Function returning an iterable object by level with all the logs in the SDK, also a generator should be available:

for(var logEntry of sdk.getLogEntries('Info')) {
    console.log(logEntry); // Outputs all the log entries
}

const sequence = sdk.getLogEntries('Info').generator();
console.log(sequence.next().value); // Outputs first entry

The SDK should be exported as the default value in the index file of the src folder.

The SDK will be validated using npm test. Don't change anything outside the src folder.