Re-running r.js gives parse error for first dependency

[webpro]

When re-running r.js with the configured output dir not being empty (i.e. when running r.js without first removing this directory), I get the following error:

Tracing dependencies for: main
Error: Parse error using UglifyJS for file: [...]/src-build/js/app.js
Unexpected token: eof (undefined) (line: 1, col: 55, pos: 55)

Error
    at new JS_Parse_Error ([...]/r.js:9633:22)

In module tree:
    main

When I simply remove the output directory first, everything runs fine. Perhaps best to simply remove/empty the directory before tracing dependencies. (Although this could actually be another, more serious bug.)

[jrburke]

Do you have a test case I can try? I tried with a simpler project here, but I do not see the issue. I think it may be related to how uglify uglifies the code the first time. Feel free to pass it to me off list if it should be private.

[pixelhandler]

jrburke, I think I have a similar issue and do have a test project, see : #187

-Bill

[webpro]

Apologies for not being more thorough initially.

First of all, it seems wrong to me to trace module dependencies using the uglified files in the output folder of a previous run. Maybe this is for performance reasons?

Second, this configuration I added led to identifying the issue:

"onBuildRead": function(moduleName, path, contents) {
    return contents.replace(/console\.(.*)/g, '');
}

The first time I run r.js, the contents enter this function unoptimized, but the second time, contents is uglified. Imho, the code should never be uglified until after "onBuildRead".

(So after the first run, with this configuration I have, the contents is already uglified before this function is called. And my regexp strips the rest of the lines having "console.", which now contains more code.)

The problem in the end is (besides my error-prone regexp) that this function is executed using different code (in first vs. consecutive runs).

Let me know if you still need a test case.

Edit: I'm also willing to dive into your sources and offer a pull request.

[jrburke]

@webpro thanks for the extra info. Your feedback has brought me around to by default removing the build dir before each build run, and have an opt in option to keep it. I think more people are hitting this issue now that the onBuild* processors are available. I opened #191 to track the specific code change now that we have identified a path for it.

@pixelhandler I will follow up in #187 on that issue. Thanks for the repo that I can pull to try out the problem, I will be doing that shortly.

I'll close this bug now that we have the more targeted #191, and I'll follow up in #187 separately. Put a comment in #191 if you want to get notified when it is fixed so that you can try out the r.js snapshot that will go with the fix.