jsverify VS UglifyJS2

Libraries like JSVerify or Fast-Check offer essential tools to facilitate property-based testing.

I tend to use anything that offers property-testing, since tests are much shorter to write and uncover lots more hidden assumptions.

My go-to choices per language are:

- Python: Hypothesis https://hypothesis.readthedocs.io/en/latest (also compatible with PyTest)

- Scala: ScalaCheck https://scalacheck.org (also compatible with ScalaTest)

- Javascript/Typescript: JSVerify https://jsverify.github.io

- Haskell: LazySmallCheck2012 https://github.com/UoYCS-plasma/LazySmallCheck2012/blob/mast...

- When I wrote PHP (over a decade ago) there was no decent property-based test framework, so I cobbled one together https://github.com/Warbo/php-easycheck

All of the above use the same basic setup: tests can make universally-quantified statements (e.g. "for all (x: Int), foo(x) == foo(foo(x))"), then the framework checks that statement for a bunch of different inputs.

Most property-checking frameworks generate data randomly (with more or less sophistication). The Haskell ecosystem is more interesting:

- QuickCheck was one of the first property-testing frameworks, using random genrators.

- SmallCheck came later, which enumerates data instead (e.g. testing a Float might use 0, 1, -1, 2, -2, 0.5, -0.5, etc.). That's cute, but QuickCheck tends to exercise more code paths with each input.

- LazySmallCheck builds up test data on-demand, using Haskell's pervasive laziness. Tests are run with an error as input: if they pass, we're done; if they fail, we're done; if they trigger the error, they're run again with slightly more-defined inputs. For example, if the input is supposed to be a list, we try again with the two forms of list: empty and "cons" (the arguments to cons are both errors, to begin with). This exercises even more code paths for each input.

- LazySmallCheck2012 is a more versatile "update" to LazySmallCheck; in particular, it's able to generate functions.

The usage of hypothesis is very intuitive and simple, and presents the concept of property-based testing perfectly. So I also wanted to find an equivalent alternative in Node. Two of them have high star ratings on Github, JSVerify with 1.6K stars and fast-check with 2.8K stars. So I took some time to study fast-check a little bit and try to get closer to my daily work.

Systems I've used for this include https://agda.readthedocs.io/en/v2.6.0.1/getting-started/what... https://coq.inria.fr https://www.idris-lang.org and https://isabelle.in.tum.de

An easier alternative is to try disproving the statement, by executing it on thousands of examples and seeing if any fail. That gives us less confidence than a full proof, but can still be better than traditional "there exists" tests. This is called property checking or property-based testing. Systems I've used for this include https://hypothesis.works https://hackage.haskell.org/package/QuickCheck https://scalacheck.org and https://jsverify.github.io

Using create-react-app, you’ll run npm test which uses Jest internally. If you are dealing with a lot of data on the UI, or using TypeScript, use JSVerify for property tests. For end to end tests, Cypress is a great choice.

Minification involves removing unnecessary characters, whitespace, and comments from code files. It helps reduce HTML, CSS, JavaScript, etc., file sizes without compromising functionality. Removing redundant elements makes these HTML, JavaScript, and CSS files smaller. Since smaller code files need less internet traffic to transfer, they load faster. Utilizing tools like UglifyJS, Clean-CSS, and HTMLMinifier enhances this process of code reduction. They analyze the code, remove redundant code, and generate optimized files for deployment.

Example: You've got a main.js file that's as long as a Tolstoy novel. Fix: Use tools like UglifyJS or Terser to minify your code. They'll squeeze out all the unnecessary bits and give you a sleeker, faster-loading file.

Minification: UglifyJS, Terser

There are a bunch of libraries that do this, but my current go to is Uglify: https://www.npmjs.com/package/uglify-js

There are many minifiers such as terser and uglify. But, because minifying also require to parse the JS, it is actually possible to use esbuild and SWC to minify the code. Here's a benchmark of the main minifiers.

In my understanding, UglifyJS 3 is the most popular JavaScript minifier tool presently -- it has a very high weekly download too. And as per the official documentation, it supports ES6.

I'm thinking reverse-engineered uglified js code (https://github.com/mishoo/UglifyJS) is not as impenetrable as code from reversed engineered wasm binaries? The element of plausible deniability is much more potent though, for the nefarious actor on the other side.

Program: uglifyjs Arguments: $FileName$ -c -m -o $FileNameWithoutExtension$.min.js

Apart from terser, you can also use uglify-js to compress or minify javascript.

Uglify