might-cli/build/diff.js

A no-code solution for performing frontend tests

import jimp from 'jimp';
import looksSame from 'looks-same';
export async function difference(reference, current, tolerance, antialiasingTolerance) {
    const opts = {
        tolerance,
        strict: false,
        ignoreCaret: true,
        ignoreAntialiasing: true,
        antialiasingTolerance
    };
    const ref = await reference.getBufferAsync(jimp.MIME_PNG);
    const cur = await current.getBufferAsync(jimp.MIME_PNG);
    return new Promise((resolve, reject) => {
        looksSame(ref, cur, opts, (err, result) => {
            if (err) {
                reject(err);
                return;
            }
            if (!result.equal) {
                looksSame.createDiff({
                    current: cur,
                    reference: ref,
                    highlightColor: '#FF00FF',
                    ...opts
                }, (err, buffer) => {
                    if (err) {
                        reject(err);
                        return;
                    }
                    resolve({
                        same: false,
                        differences: 1,
                        diffImage: detailedDifference(reference, current, buffer)
                    });
                });
            }
            else {
                resolve({
                    same: true
                });
            }
        });
    });
}
async function detailedDifference(reference, current, diffBuffer) {
    const width = reference.getWidth();
    const height = reference.getHeight();
    const margin = Math.min(50, width * 0.15);
    const diff = await jimp.read(diffBuffer);
    const halfReference = reference.clone();
    const final = await jimp.create((width * 2) + margin, (height * 2) + margin);
    final.composite(current, 0, 0);
    final.composite(reference, width + margin, 0);
    halfReference.opacity(0.35);
    final.composite(current, 0, height + margin);
    final.composite(halfReference, 0, height + margin);
    final.composite(diff, width + margin, height + margin);
    return final.getBufferAsync(jimp.MIME_PNG);
}