56 lines
1.7 KiB
Markdown
56 lines
1.7 KiB
Markdown
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unreachable-branch-transform
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============================
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Removes unreachable code branches in `if` statements, ternaries `?`, and logical operations `||` `&&`, where the test is determinable (like comparing two constants). This is similar to what [UglifyJS](https://github.com/mishoo/UglifyJS2)'s "dead_code" compressor option does, but without the extra code transformations.
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When combined with something like [envify](https://github.com/hughsk/envify) and [browserify](https://github.com/substack/node-browserify), you can perform conditional `require` calls without including more code than you need.
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#### Install ####
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```bash
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npm install unreachable-branch-transform
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```
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#### Example outputs #####
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```js
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// original
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var transport = process.env.TARGET === 'client' ? require('ajax') : require('fs');
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// after envify
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var transport = 'server' === 'client' ? require('ajax') : require('fs');
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// then after unreachable-branch-transform
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var transport = require('fs');
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```
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```js
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// original
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if (process.env.NODE_ENV === 'development') {
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console.log('in dev mode');
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} else {
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console.log('in some other mode');
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}
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// after envify
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if ('production' === 'development') {
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console.log('in dev mode');
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} else {
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console.log('in some other mode');
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}
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// then after unreachable-branch-transform
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{
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console.log('in some other mode');
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}
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```
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#### Usage #####
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* `unreachable-branch-transform` can be used a [browserify](https://github.com/substack/node-browserify) transform. Just include it like any other transform.
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* `unreachable-branch-transform` can also be used on raw code by calling the `transform` function exposed by requiring the package.
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Credit
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------
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`esmangle-evaluator` is from the [esmangle](https://github.com/Constellation/esmangle) project.
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