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6 years ago
'use strict';
const execBuffer = require('exec-buffer');
const isPng = require('is-png');
const optipng = require('optipng-bin');
module.exports = opts => buf => {
opts = Object.assign({
optimizationLevel: 3,
bitDepthReduction: true,
colorTypeReduction: true,
paletteReduction: true
}, opts);
if (!Buffer.isBuffer(buf)) {
return Promise.reject(new TypeError('Expected a buffer'));
}
if (!isPng(buf)) {
return Promise.resolve(buf);
}
const args = [
'-strip', 'all',
'-clobber',
'-fix',
'-o', opts.optimizationLevel,
'-out', execBuffer.output
];
if (!opts.bitDepthReduction) {
args.push('-nb');
}
if (!opts.colorTypeReduction) {
args.push('-nc');
}
if (!opts.paletteReduction) {
args.push('-np');
}
args.push(execBuffer.input);
return execBuffer({
input: buf,
bin: optipng,
args
}).catch(err => {
err.message = err.stderr || err.message;
throw err;
});
};