Reduce package size

[GreenImp]

Is your feature request related to a problem? Please describe.
The NPM bundle size is higher than I'd like and I think there's a lot of superfluous files in there, such as the .travis.yml file, the demo files etc.
These files are handy for working on the library, but not needed for working with the library.

Describe the solution you'd like
We should use either an .npmignore file to exclude files we don't want in the package, or add a whitelist of files to include in the package.json file.

It may also be worth completely removing the demo files as everything is explained in detail in the readme.

There's also an argument that the source files and tests should be excluded, but I'm uncertain what's best here.

Updated table of package sizes as calculated by various things:

	v4.5.1	v5.4.1	Latest	Next
NPM tarball	package size: 329.1 kB unpacked size: 1.7 MB	package size: 107.0 kB unpacked size: 580.4 kB	package size: 108.1 kB unpacked size: 588.6 kB
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[GreenImp]

The package is currently 1.4MB
The biggest part of the package is the compiled JS, which is compounded by the fact that we've got both ESM and UMD versions as they're ~507kb and ~561kb respectively.

I think this is likely because of the math library, but replacing that could be tricky as we would need to find a library with a similar range of abilities. Although, it looks like the main mathjs library now supports ES modules, so we could just bring in the bits we need: https://mathjs.org/docs/getting_started.html#es-modules

npm notice 📦  rpg-dice-roller@4.0.3
npm notice === Tarball Contents === 
npm notice 142B    .babelrc                                       
npm notice 240B    .editorconfig                                  
npm notice 87B     .eslintrc                                      
npm notice 6.0kB   demo/index.html                                
npm notice 5.9kB   demo/index.umd.html                            
npm notice 507.1kB lib/esm/bundle.js                              
npm notice 561.4kB lib/umd/bundle.js                              
npm notice 2.2kB   src/ComparePoint.js                            
npm notice 9.0kB   tests/ComparePoint.test.js                     
npm notice 1.3kB   src/modifiers/ComparisonModifier.js            
npm notice 5.2kB   tests/modifiers/ComparisonModifier.test.js     
npm notice 708B    src/modifiers/CriticalFailureModifier.js       
npm notice 7.4kB   tests/modifiers/CriticalFailureModifier.test.js
npm notice 773B    src/modifiers/CriticalSuccessModifier.js       
npm notice 7.4kB   tests/modifiers/CriticalSuccessModifier.test.js
npm notice 204B    src/Dice.js                                    
npm notice 8.8kB   src/DiceRoll.js                                
npm notice 19.2kB  tests/DiceRoll.test.js                         
npm notice 5.2kB   src/DiceRoller.js                              
npm notice 9.8kB   tests/DiceRoller.test.js                       
npm notice 536B    src/modifiers/DropModifier.js                  
npm notice 11.4kB  tests/modifiers/DropModifier.test.js           
npm notice 3.0kB   src/modifiers/ExplodeModifier.js               
npm notice 16.1kB  tests/modifiers/ExplodeModifier.test.js        
npm notice 234B    src/parser/foo.js                              
npm notice 1.5kB   src/dice/FudgeDice.js                          
npm notice 11.4kB  tests/dice/FudgeDice.test.js                   
npm notice 632B    src/parser/grammars/generate.js                
npm notice 364B    src/index.js                                   
npm notice 2.9kB   src/modifiers/KeepModifier.js                  
npm notice 11.4kB  tests/modifiers/KeepModifier.test.js           
npm notice 990B    src/modifiers/Modifier.js                      
npm notice 775B    src/Modifiers.js                               
npm notice 743B    src/parser/Parser.js                           
npm notice 51.7kB  tests/parser/Parser.test.js                    
npm notice 465B    src/dice/PercentileDice.js                     
npm notice 9.1kB   tests/dice/PercentileDice.test.js              
npm notice 2.3kB   src/modifiers/ReRollModifier.js                
npm notice 8.9kB   tests/modifiers/ReRollModifier.test.js         
npm notice 1.2kB   src/RollGroup.js                               
npm notice 8.0kB   tests/rolling.test.js                          
npm notice 5.2kB   src/results/RollResult.js                      
npm notice 16.4kB  tests/results/RollResult.test.js               
npm notice 1.7kB   src/results/RollResults.js                     
npm notice 6.4kB   tests/results/RollResults.test.js              
npm notice 995B    rollup.config.js                               
npm notice 1.4kB   src/modifiers/SortingModifier.js               
npm notice 5.5kB   tests/modifiers/SortingModifier.test.js        
npm notice 4.8kB   src/dice/StandardDice.js                       
npm notice 9.4kB   tests/dice/StandardDice.test.js                
npm notice 3.9kB   src/modifiers/TargetModifier.js                
npm notice 9.9kB   tests/modifiers/TargetModifier.test.js         
npm notice 4.4kB   src/utilities/utils.js                         
npm notice 25B     lib/umd/package.json                           
npm notice 2.2kB   package.json                                   
npm notice 835B    .github/ISSUE_TEMPLATE/bug_report.md           
npm notice 603B    .github/ISSUE_TEMPLATE/feature-request.md      
npm notice 34.2kB  readme.md                                      
npm notice 4.3kB   src/parser/grammars/grammar.pegjs              
npm notice 150B    banner.txt                                     
npm notice 1.1kB   licence.txt                                    
npm notice 98B     .travis.yml                                    
npm notice === Tarball Details === 
npm notice name:          rpg-dice-roller                         
npm notice version:       4.0.3                                   
npm notice package size:  252.1 kB                                
npm notice unpacked size: 1.4 MB                                  
npm notice shasum:        1b1df9da06230ed09c8b0643342271a074d1f4e9
npm notice integrity:     sha512-jtAapqgywB3R/[...]fbH3XfJtjNKEg==
npm notice total files:   63

Even if I remove all of the other files that aren't necessary for use, it comes in at 1.1MB:

npm notice 📦  rpg-dice-roller@4.0.3
npm notice === Tarball Contents === 
npm notice 507.1kB lib/esm/bundle.js   
npm notice 561.4kB lib/umd/bundle.js   
npm notice 25B     lib/umd/package.json
npm notice 2.2kB   package.json        
npm notice 34.2kB  readme.md           
npm notice 1.1kB   licence.txt         
npm notice === Tarball Details === 
npm notice name:          rpg-dice-roller                         
npm notice version:       4.0.3                                   
npm notice package size:  208.1 kB                                
npm notice unpacked size: 1.1 MB                                  
npm notice shasum:        764963ffb2f33cdc149d7614b30f2ede34779cbd
npm notice integrity:     sha512-M+lr8cq4TEcii[...]jwhtYgFzHTC6w==
npm notice total files:   6

If we publish the minified JS instead, this does drastically reduce the package size to only 343.2KB, so maybe that's the best option. I'm not sure what the general view is on only supplying minimised code though.

npm notice 📦  rpg-dice-roller@4.0.3
npm notice === Tarball Contents === 
npm notice 148.8kB lib/esm/bundle.min.js
npm notice 156.9kB lib/umd/bundle.min.js
npm notice 25B     lib/umd/package.json 
npm notice 2.2kB   package.json         
npm notice 34.2kB  readme.md            
npm notice 1.1kB   licence.txt          
npm notice === Tarball Details === 
npm notice name:          rpg-dice-roller                         
npm notice version:       4.0.3                                   
npm notice package size:  86.3 kB                                 
npm notice unpacked size: 343.2 kB                                
npm notice shasum:        50873f24eb7780d76bb321500c2ad994416d9312
npm notice integrity:     sha512-sqdUTp2FURRsi[...]9JJeddrIyyg2w==
npm notice total files:   6

[GreenImp]

So it looks like not publishing the uncompressed files is a no-go, as it can make it difficult for devs to use the library, if they need to do thier own minifications.

I think this is a definitive list of all the files that should be included, and the file sizes:

npm notice 📦  rpg-dice-roller@4.0.3
npm notice === Tarball Contents === 
npm notice 511.6kB lib/esm/bundle.js    
npm notice 570.7kB lib/umd/bundle.js    
npm notice 148.6kB lib/esm/bundle.min.js
npm notice 158.9kB lib/umd/bundle.min.js
npm notice 25B     lib/umd/package.json 
npm notice 2.5kB   package.json         
npm notice 10.9kB  CONTRIBUTING.md      
npm notice 34.4kB  readme.md            
npm notice 1.1kB   licence.txt          
npm notice === Tarball Details === 
npm notice name:          rpg-dice-roller                         
npm notice version:       4.0.3                                   
npm notice package size:  290.2 kB                                
npm notice unpacked size: 1.4 MB                                  
npm notice shasum:        c47dc90ba453a37304c7522a661d40413365061c
npm notice integrity:     sha512-T7j5fZNCM0mxZ[...]FfDuTK9B9O+Pg==
npm notice total files:   9

It's still rather large, as expected, because the compiled scripts are quite big.

I'm going to play around with the mathJS library, to see if using the full version (Which supports ES modules and tree shaking!) can actually decrease the compiled size.

[GreenImp]

I can't seem to get the mathJS library working with Jest - it complains about unexpected export. I think it's because the mathJS library is defined as an ES5 package, that contains some ES6 files, but there isn't anything specifying that they're ES6 modules, so Jest tries to load them as ES5 scripts.

Either way, I think I'll leave it as is for now. I've got an .npmignore file set up to exclude all the files that aren't required which, although it doesn't reduce the bundle size much, at least makes the directory structure cleaner.

[GreenImp]

I've just found that Rollup can be told not to bundle external dependencies, which means that I could get it to ignore the MathJS library when bundling.
That means that the compiled scripts will be much smaller, but we can still leave MathJS as a dependency in the package.json so it gets brought in.

It looks like I might even be able to get Rollup to ignore any dependencies in my package.json file: https://medium.com/@kelin2025/so-you-wanna-use-es6-modules-714f48b3a953#726c

If this works, we'll need to add a note to the readme for anyone using the UMD file directly, rather than npm / yarn, that they'll need to include the mathJS script themselves.

[dixhuit]

I've just been evaluating rpg-dice-roller as a replacement for another lib that I'm currently using but when compiled for production I'm seeing an increased bundle size of 0.8 MB. Granted, rpg-dice-roller offers a lot more but even then this is currently a bit hard to swallow.

I'm very interested in any of the improvements discussed in this thread 👍

[GreenImp]

Hey @danbohea. Yeah it's a lot larger than I'd like at the moment, because it's got the entire MathJs library, and random-js libraries included in the bundled files.

I tried decoupling them, so they're not included in the bundle but have had some difficulty getting it to work. I'm planning on taking another look at it as one of the next things, but also more than happy for any PRs that can sort it.