Example 3-16. Verbose pipeline

This example has been corrected from the original version by adding return Promise.resolve(image).then(function (image) { as the first line of the processImage function.

// Generic image processing functions
function scaleToFit(width, height, image) {
	console.log('Scaling image to ' + width + ' x ' + height);
	return image;
}

function watermark(text, image) {
	console.log('Watermarking image with ' + text);
	return image;
}

function grayscale(image) {
	console.log('Converting image to grayscale');
	return image;
}

// Image processing pipeline
function processImage(image) {
	return Promise.resolve(image).then(function (image) {
		return scaleToFit(300, 450, image);
	}).then(function (image) {
		return watermark('The Real Estate Company', image);
	}).then(function (image) {
		return grayscale(image);
	});
}

// Console output for processImage():
// Scaling image to 300 x 450
// Watermarking image with The Real Estate Company
// Converting image to grayscale