Add support for streams

index.js

@@ -1,23 +1,23 @@
 'use strict';
-const execBuffer = require('exec-buffer');
+const execa = require('execa');
 const isPng = require('is-png');
+const isStream = require('is-stream');
 const pngquant = require('pngquant-bin');
 
-module.exports = opts => buf => {
+module.exports = opts => input => {
 	opts = Object.assign({}, opts);
 
-	if (!Buffer.isBuffer(buf)) {
-		return Promise.reject(new TypeError('Expected a buffer'));
+	const isBuffer = Buffer.isBuffer(input);
+
+	if (!isBuffer && !isStream(input)) {
+		return Promise.reject(new TypeError(`Expected a Buffer or Stream, got ${typeof input}`));
 	}
 
-	if (!isPng(buf)) {
-		return Promise.resolve(buf);
+	if (isBuffer && !isPng(input)) {
+		return Promise.resolve(input);
 	}
 
-	const args = [
-		'--output', execBuffer.output,
-		execBuffer.input
-	];
+	const args = ['-'];
 
 	if (opts.floyd && typeof opts.floyd === 'number') {
 		args.push(`--floyd=${opts.floyd}`);
@@ -47,16 +47,24 @@ module.exports = opts => buf => {
 		args.push('--verbose');
 	}
 
-	return execBuffer({
-		input: buf,
-		bin: pngquant,
-		args
-	}).catch(err => {
-		if (err.code === 99) {
-			return buf;
-		}
-
-		err.message = err.stderr || err.message;
-		throw err;
+	const cp = execa(pngquant, args, {
+		encoding: null,
+		input
 	});
+
+	const promise = cp
+		.then(res => res.stdout)
+		.catch(err => {
+			if (err.code === 99) {
+				return input;
+			}
+
+			err.message = err.stderr || err.message;
+			throw err;
+		});
+
+	cp.stdout.then = promise.then.bind(promise);
+	cp.stdout.catch = promise.catch.bind(promise);
+
+	return cp.stdout;
 };

package.json

@@ -40,13 +40,14 @@
     "pngquant"
   ],
   "dependencies": {
-    "exec-buffer": "^3.0.0",
+    "execa": "^0.8.0",
     "is-png": "^1.0.0",
+    "is-stream": "^1.1.0",
     "pngquant-bin": "^3.0.0"
   },
   "devDependencies": {
     "ava": "*",
-    "pify": "^3.0.0",
+    "get-stream": "^3.0.0",
     "xo": "*"
   }
 }

readme.md

@@ -24,9 +24,9 @@ imagemin(['images/*.png'], 'build/images', {use: [imageminPngquant()]}).then(()
 
 ## API
 
-### imageminPngquant([options])(buffer)
+### imageminPngquant([options])(input)
 
-Returns a promise for a buffer.
+Returns a `Promise` for a `Buffer`.
 
 #### options
 
@@ -76,11 +76,11 @@ Default: `false`
 
 Print verbose status messages.
 
-#### buffer
+#### input
 
-Type: `Buffer`
+Type: `Buffer` `Stream`
 
-Buffer to optimize.
+Buffer or stream to optimize.
 
 
 ## License

test.js

@@ -1,22 +1,20 @@
 import fs from 'fs';
 import path from 'path';
+import getStream from 'get-stream';
 import isPng from 'is-png';
-import pify from 'pify';
 import test from 'ava';
-import m from './';
-
-const fsP = pify(fs);
+import m from '.';
 
 test('optimize a PNG', async t => {
-	const buf = await fsP.readFile(path.join(__dirname, 'fixture.png'));
+	const buf = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
 	const data = await m()(buf);
 
 	t.true(data.length < buf.length);
 	t.true(isPng(data));
 });
 
 test('support pngquant options', async t => {
-	const buf = await fsP.readFile(path.join(__dirname, 'fixture.png'));
+	const buf = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
 	const data = await m({
 		speed: 10,
 		quality: 100
@@ -26,15 +24,24 @@ test('support pngquant options', async t => {
 	t.true(isPng(data));
 });
 
+test('support streams', async t => {
+	const buf = await fs.readFileSync(path.join(__dirname, 'fixture.png'));
+	const stream = fs.createReadStream(path.join(__dirname, 'fixture.png'));
+	const data = await getStream.buffer(m()(stream));
+
+	t.true(data.length < buf.length);
+	t.true(isPng(data));
+});
+
 test('skip optimizing a non-PNG file', async t => {
-	const buf = await fsP.readFile(__filename);
+	const buf = await fs.readFileSync(__filename);
 	const data = await m()(buf);
 
 	t.is(data.length, buf.length);
 });
 
 test('skip optimizing a fully optimized PNG', async t => {
-	const buf = await fsP.readFile(path.join(__dirname, 'fixture-no-compress.png'));
+	const buf = await fs.readFileSync(path.join(__dirname, 'fixture-no-compress.png'));
 	const data = await m({quality: 100})(buf);
 	t.is(data.length, buf.length);
 	t.true(isPng(data));