move patching of RN packager into a separate command 'enable-source-maps'

- patching the packager in 'upgrade' command is a bit too intrusive, this can be done optionally only when source maps are actually needed.

README.md

@@ -33,7 +33,7 @@ Contributions are welcome.
   - Simultaneous development of iOS and Android apps is supported
   - You can reload app any time, no problem.
   - Custom react-native components are supported (with re-natal use-component <name>)
-  - Source maps are available when you "Debug in Chrome"
+  - Source maps are available when you "Debug in Chrome" (with re-natal enable-source-maps)
 - Optimizations :simple is used to compile "production" index.ios.js and index.android.js
 - [Unified way of using static images of rn 0.14+](https://facebook.github.io/react-native/docs/images.html) works
 - Works on Linux and Windows (Android only)
@@ -272,13 +272,16 @@ To upgrade React Native to newer version please follow the official
 [Upgrading](https://facebook.github.io/react-native/docs/upgrading.html) guide of React Native.
 Re-Natal makes almost no changes to the files generated by react-native so the official guide should be valid.
 
-### Changes Re-Natal does to original RN application
-It would be perfect not to do any changes there, but...
-* To make source maps available in "Debug in Chrome" mode re-natal patches
+### Enabling source maps when debugging in chrome
+To make source maps available in "Debug in Chrome" mode re-natal patches
 the react native packager to serve \*.map files from file system and generate only index.\*.map file.
-To achieve this [this line](https://github.com/facebook/react-native/blob/master/packager/react-packager/src/Server/index.js#L408)
+To achieve this [this line](https://github.com/facebook/react-native/blob/master/packager/react-packager/src/Server/index.js#L413)
 of file "node_modules/react-native/packager/react-packager/src/Server/index.js" is modified to match only index.\*.map
 
+To do this run: `re-natal enable-source-maps` and restart packager.
+
+You can undo this any time by deleting `node_modules` and running `re-natal deps`
+
 ## Example Apps
 * [Luno](https://github.com/alwx/luno-react-native) is a demo mobile application written in ClojureScript.
 

re-natal.coffee

@@ -230,6 +230,7 @@ updateGitIgnore = () ->
   fs.appendFileSync(".gitignore", "\n# Figwheel\n#\nfigwheel_server.log")
 
 patchReactNativePackager = () ->
+  ckDeps.sync {install: true, verbose: false}
   log "Patching react-native packager to serve *.map files"
   edit "node_modules/react-native/packager/react-packager/src/Server/index.js",
     [[/match.*\.map\$\/\)/m, "match(/index\\..*\\.map$/)"]]
@@ -428,10 +429,6 @@ doUpgrade = (config) ->
   projNameHyph = projName.replace(camelRx, '$1-$2').toLowerCase()
   projNameUs   = toUnderscored projName
 
-  ckDeps.sync {install: true, verbose: false}
-
-  patchReactNativePackager()
-
   copyDevEnvironmentFiles(projNameHyph, projName, "localhost")
   copyProdEnvironmentFiles(projNameHyph, projName)
   log 'upgraded files in env/'
@@ -517,6 +514,11 @@ cli.command 'use-component <name>'
   .action (name) ->
     useComponent(name)
 
+cli.command 'enable-source-maps'
+.description 'patches RN packager to server *.map files from filesystem, so that chrome can download them.'
+.action () ->
+  patchReactNativePackager()
+
 cli.command 'copy-figwheel-bridge'
   .description 'copy figwheel-bridge.js into project'
   .action () ->