Specifically, esbuild is not made to preserve the value of getting in touch with
The new JavaScript minification algorithm when you look at the esbuild usually builds output that is very nearby the minified productivity sized globe-basic JavaScript minification devices. When you’re esbuild is not necessarily the optimal JavaScript minifier in most times (and you will will not try to be), they strives to create minified productivity within this a few % of the dimensions of faithful minification devices for most password, and additionally to achieve this much faster than other gadgets.
#Considerations
You need to most likely in addition to set the goal choice whenever minification are enabled. Automagically esbuild utilizes progressive JavaScript possess and come up with their code less. For example, an effective === undefined || an excellent === null ? 1 : a might minified to help you an excellent ?? step 1 . Unless you require esbuild when planning on taking advantage of progressive JavaScript have whenever minifying, you can use an older vocabulary address such –target=es6 .
The smoothness stay away from sequence \n is substituted for an effective newline profile inside JavaScript template literals. Sequence literals will also be changed into template literals in case your address aids her or him of course performing this manage end in faster returns. This is not a bug. Minification function you’re asking for quicker production, and eliminate series \letter takes a couple of bytes while the newline character takes one byte.
Automatically esbuild won’t minify the names of top-height declarations. The reason being esbuild does not know what you’re starting into efficiency. You happen to be inserting this new minified code towards the center away from some other password, in which particular case minifying ideal-height parece will be unsafe. Means a returns structure (or permitting bundling, which picks a returns style for your requirements for people who have not lay one) tells esbuild the output could well be manage within the very own scope, and thus it’s following safer so you’re able to minify greatest-peak es.
Minification isn’t safe for a hundred% of the many JavaScript code. This can be real having esbuild as well as most other prominent JavaScript minifiers like terser. toString() towards the a features. The reason behind the reason being if the the password in to the the properties had to be managed verbatim, minification do barely do anything at all and you will was practically inadequate. not, this is why JavaScript code depending on the come back value of .toString() will most likely crack whenever minified. Eg, specific designs on AngularJS structure split when code are minified due to the fact AngularJS spends .toString() to learn the latest conflict labels away from qualities. Good workaround is to apply explicit annotations alternatively.
Automatically esbuild will not manage the value for the mode and you can class items. The reason being very code cannot trust so it assets and you will playing with shorter names is an important proportions optimisation. However, certain password really does trust property getting membership and you may joining aim. If you wish to believe in it you really need to let the remain labels choice.
Usage of specific JavaScript has actually is also eliminate a lot of esbuild’s optimizations in addition to minification. Specifically, having fun with head eval and you can/or the that have declaration avoid esbuild from renaming identifiers to help you less brands because these has actually trigger identifier joining to take place within focus on go out instead of secure go out. This really is always accidental, and simply happens because everyone is unacquainted with what head eval is and just why it’s crappy.
The new minification algorithm for the esbuild doesn’t yet , manage advanced code optimizations. In particular, the following code optimizations try possible for JavaScript code but they are not carried out by esbuild (maybe not an exhaustive record):
- Dead-password reduction in this function authorities
- Means inlining
- Cross-declaration lingering propagation
- Object profile acting
- Allowance sinking
- Approach devirtualization
- Symbolic execution