Add 'src' to package.json files in templates to improve source maps

[yordis]

Since source maps point to ../src/* if people don't publish the src folder, source maps are not that useful.

[yordis]

Actually I think I am wrong on this one, it seems that the source map includes all source code content as well.

@jaredpalmer can you confirm this?

[jaredpalmer]

I think sourcemaps work fine (formik uses them)

[jaredpalmer]

but maybe not since the rollup-plugin-ts update?

[yordis]

Nah I think I made a mistake 😅 sorry

[agilgur5]

Seems very related to #494 -- @justingrant could you elaborate here on why src would be necessary to include for source maps if the .map file includes the contents of the source already?

Based on your issues in other places, is this just to be able to add breakpoints in the library source code when debugging? Or is it necessary for "Peek" / "Go to Definition" too? And maybe other things I'm missing?

[justingrant]

@agilgur5 - here's a few reasons why including src is helpful, especially for IDE users:

• You can set a breakpoint before starting a debug session in your IDE. This is helpful for debugging startup issues. I also do this sometimes whenever I add a new dependency where I want to step through it in the debugger the very first time I use it so I can make sure that I'm using it properly. By setting a breakpoint immediately after I npm install the library, it ensures that I remember to debug through it even if the first time I actually debug that code isn't until a week later.
• You can use the IDE's file-search features to find the source of specific methods or code in the library source (and optionally set a breakpoint there) without having to shell out to GitHub to do the search there, and then to manually correlate what you see in GitHub to the library source.
• Apps that use webpack to bundle libraries which have ghost sources entries (where those source files don't exist on disk) can cause VSCode may load the wrong source file in the debugger. This can happen when a sourcemap contains a relative path in a sources entry (e.g. ./src/index.ts) that also exists in the app. VSCode tries multiple base paths to convert an entry in sources to a full path on disk, and if you get a match (even a false positive match) then VSCode will never even load the inline source.
• Some build tools will report a warning when a source file is present in sources but not on disk.
• [EDIT] Go To Declaration using declaration maps might also require original source files. Not sure about this one though-- would need to test it.

[agilgur5]

Thanks for the great write-up @justingrant ! I didn't know about the VSCode base paths Issue 😰
Does "Peek"/"Go to Definition" work without the source? I believe it works a little differently when you have the source but I'm not totally sure.

In any case, I'll re-open and merge this PR. Or rather, apparently can't re-open as the repo/branch doesn't exist any more on the fork, so I'll have to open a new PR

[justingrant]

Does "Peek"/"Go to Definition" work without the source? I believe it works a little differently when you have the source but I'm not totally sure.

@agilgur5 - my understanding is that Go to Definition will navigate to a library's original source if: a) there's a valid declaration map (.d.ts.map); AND b) the original source files that the declaration map refers to are present on disk.

That said I've been told on another thread that folks can't get declaration maps working at all (even if the conditions above are satisfied) so there may be some other problem going on.

Regardless, I strongly suspect that Go To Definition won't go to original source if the original source files are missing, because AFAIK the IDE won't load the source in the sourcemap file unless the debugger is running.

[agilgur5]

Gotcha. Thanks for filling in the knowledge gaps!

I opened and merged #620 (while crediting OP here) to add src to the default package.json.files 👍

@allcontributors please add @justingrant for questions

[agilgur5]

@allcontributors please add @justingrant for questions

it seems to fail occasionally if you only mention one type of contribution 🤷‍♂

[allcontributors]

@agilgur5

I've put up a pull request to add @justingrant! 🎉