Develop

.travis.yml

@@ -3,6 +3,7 @@ go:
   - 1.13.x
 env:
   - GO111MODULE=on
+  - CGO_ENABLED=0
 before_install:
   - go get github.com/mattn/goveralls
 script:

README.md

@@ -50,19 +50,10 @@ The core functionality associates mimetypes with minification functions, allowin
 		- [Templates](#templates)
 	- [License](#license)
 
-### Status
-
-* CSS: **fully implemented**
-* HTML: **fully implemented**
-* JS: improved JSmin implementation
-* JSON: **fully implemented**
-* SVG: partially implemented; in development
-* XML: **fully implemented**
-
 ### Roadmap
 
 - [ ] Use ASM/SSE to further speed-up core parts of the parsers/minifiers
-- [ ] Improve JS minifiers by shortening variables and proper semicolon omission
+- [x] Improve JS minifiers by shortening variables and proper semicolon omission
 - [ ] Speed-up SVG minifier, it is very slow
 - [x] Proper parser error reporting and line number + column information
 - [ ] Generation of source maps (uncertain, might slow down parsers too much if it cannot run separately nicely)
@@ -227,19 +218,25 @@ Options:
 
 ## JS
 
-The JS minifier is pretty basic. It removes comments, whitespace and line breaks whenever it can. It employs all the rules that [JSMin](http://www.crockford.com/javascript/jsmin.html) does too, but has additional improvements. For example the prefix-postfix bug is fixed.
+The JS minifier typically shaves off about 35% -- 65% of filesize depening on the file, which is a compression close to many other minifiers. Common speeds of PHP and JS implementations are about 100-300kB/s (see [Uglify2](http://lisperator.net/uglifyjs/), [Adventures in PHP web asset minimization](https://www.happyassassin.net/2014/12/29/adventures-in-php-web-asset-minimization/)). This implementation is orders of magnitude faster at around ~25MB/s.
 
-Common speeds of PHP and JS implementations are about 100-300kB/s (see [Uglify2](http://lisperator.net/uglifyjs/), [Adventures in PHP web asset minimization](https://www.happyassassin.net/2014/12/29/adventures-in-php-web-asset-minimization/)). This implementation or orders of magnitude faster, around ~80MB/s.
+The following features are implemented:
 
-TODO:
-- shorten local variables / function parameters names
-- precise semicolon and newline omission
+- remove superfluous whitespace
+- remove superfluous semicolons
+- shorten `true`, `false`, and `undefined` to `!0`, `!1` and `void 0`
+- rename variables and functions to shorter names (not in global scope)
+- collapse if/else statements to expressions
+- merge sequential expression statements to one, including into `return` and `throw`
+- remove superfluous grouping in expressions
+- shorten or remove string escapes
+- convert object key or index expression from string to identifier or decimal
 
 ## JSON
 
 Minification typically shaves off about 15% of filesize for common indented JSON such as generated by [JSON Generator](http://www.json-generator.com/).
 
-The JSON minifier only removes whitespace, which is the only thing that can be left out.
+The JSON minifier only removes whitespace, which is the only thing that can be left out, and minifies numbers (`1000` => `1e3`).
 
 Options:
 

benchmarks/benchmark_test.go

@@ -0,0 +1,107 @@
+package benchmarks
+
+import (
+	"io/ioutil"
+	"runtime"
+	"testing"
+
+	"github.com/tdewolff/minify/v2/minify"
+	"github.com/tdewolff/parse/v2"
+	"github.com/tdewolff/parse/v2/buffer"
+)
+
+func benchmark(b *testing.B, mediatype string, sample string) {
+	m := minify.Default
+	buf, err := ioutil.ReadFile(sample)
+	if err != nil {
+		panic(err)
+	}
+	b.Run(sample, func(b *testing.B) {
+		b.SetBytes(int64(len(buf)))
+		for i := 0; i < b.N; i++ {
+			b.StopTimer()
+			runtime.GC()
+			r := buffer.NewReader(parse.Copy(buf))
+			w := buffer.NewWriter(make([]byte, 0, len(buf)))
+			b.StartTimer()
+
+			if err := m.Minify(mediatype, w, r); err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+}
+
+func BenchmarkCSS(b *testing.B) {
+	var samples = []string{
+		"sample_bootstrap.css",
+		"sample_gumby.css",
+		"sample_fontawesome.css",
+		"sample_normalize.css",
+	}
+	for _, sample := range samples {
+		benchmark(b, "text/css", sample)
+	}
+}
+
+func BenchmarkHTML(b *testing.B) {
+	var samples = []string{
+		"sample_amazon.html",
+		"sample_bbc.html",
+		"sample_blogpost.html",
+		"sample_es6.html",
+		"sample_stackoverflow.html",
+		"sample_wikipedia.html",
+	}
+	for _, sample := range samples {
+		benchmark(b, "text/html", sample)
+	}
+}
+
+func BenchmarkJS(b *testing.B) {
+	var samples = []string{
+		"sample_ace.js",
+		"sample_dot.js",
+		"sample_jquery.js",
+		"sample_jqueryui.js",
+		"sample_moment.js",
+	}
+	for _, sample := range samples {
+		benchmark(b, "application/javascript", sample)
+	}
+}
+
+func BenchmarkJSON(b *testing.B) {
+	var samples = []string{
+		"sample_large.json",
+		"sample_testsuite.json",
+		"sample_twitter.json",
+	}
+	for _, sample := range samples {
+		benchmark(b, "application/json", sample)
+	}
+}
+
+func BenchmarkSVG(b *testing.B) {
+	var samples = []string{
+		"sample_arctic.svg",
+		"sample_gopher.svg",
+		"sample_usa.svg",
+		"sample_car.svg",
+		"sample_tiger.svg",
+	}
+	for _, sample := range samples {
+		benchmark(b, "image/svg+xml", sample)
+	}
+}
+
+func BenchmarkXML(b *testing.B) {
+	var samples = []string{
+		"sample_books.xml",
+		"sample_catalog.xml",
+		"sample_omg.xml",
+	}
+	for _, sample := range samples {
+		benchmark(b, "application/xml", sample)
+	}
+}