`deno bundle` command will always format output by default

[wongjiahau]

The command deno bundle always format the output by default (even though it's unnecessary in some scenarios), which increase the overall bundling time.

To improve this situation, we should add a --no-format option for the sub command bundle.

[ry]

Can you provide a benchmark of how much time it adds?

I don't like adding extra options. Either we remove formatting entirely - if you can show that it's significantly slower - or it always formats.

[wongjiahau]

@ry I will provide a benchmark, but the difference will definitely be significant when the output get very larges, imagine bundling the index.ts of a React App.

Also, I'll be more than happy if the formatting is removed by default.

[ry]

@wongjiahau A concrete benchmark would really be illuminating for me - thanks. I will definitely remove formatting then.

[bartlomieju]

I'm pretty confident that formatting doesn't have big performance impact on deno bundle. Most of the time is spent on collecting modules and in TS compiler. It will be interesting to see the benchmark.

[wongjiahau]

@ry @bartlomieju I found an example, try downloading this file Terser.js minified bundle.

curl https://gist.githubusercontent.com/wongjiahau/20366c87f922eee462a8ecd172d155cb/raw/ae63b54e386759880590771a3806f1c83231d1a2/terser.min.js > terser.js

Then run:

deno fmt terser.js

It took about 4.31 seconds on my machine. (I timed this manually with my phone)

Output of deno --version:

deno 1.0.3
v8 8.4.300
typescript 3.9.2

My machine specification:

MacBook Pro (15-inch, 2018)
Processor: 2.2 GHz 6-Core Intel Core i7
Ram: 16 GB 2400 MHz DDR4

[dsherret]

I was about to say I wouldn't be surprised if it formatted slow on a minified or extremely large file. I haven't optimized it for minified files, but I bet it's spending a decent amount of time trying to figure out where newlines are (that's something I'd like to improve in the future). Perhaps it could do a quick heuristic to check if the file is minified before formatting.

[wongjiahau]

@dsherret Anyway, why do we need to add this unnecessary overhead when the output produced immediately by Typescript compiler is already formatted when the only difference with the Deno formatter is tab spacing?

[wongjiahau]

Also I would like to add on that, bundled files are usually meant to be consumed by machine rather than human, thus formatting them is like adding ice on top of ice-cream.

[kitsonk]

I tend to agree... I am surprised we are formatting bundles by default. Feels totally unnecessary.

[sholladay]

Shouldn't deno bundle | deno fmt work, for people who need it?

[wongjiahau]

@sholladay True, this is actually resolved in https://github.com/denoland/deno/pull/6085