TypeScript needs a `baseDir` option

[basarat]

Say we have the JS structure:

ts
    a.ts
    foo
    |    b.ts
    |    c.ts
js
    a.js
    foo
    |    b.js
    |    c.js

If we compile with all three files with outDir set to js its all okay. But if we only compile b.ts or c.ts with outDir set to js then we would get:

js    
    |    b.js
    |    c.js

Workaround is to create a temporary file under ts called ignoreBaseDirFile.ts and pass it to the tsc compiler

[basarat]

Reported to TS team : https://typescript.codeplex.com/workitem/2297

[basarat]

Instead of having the user specify the baseDir manually we can simply expand src and find the most common dir and assume that as the baseDir when fast compiling.

[jeffmay]

Love the idea! I think we should also have a way to override that for safety. In a large enough Org I can see people getting confused if the basedir changes on them.

[basarat]

In a large enough Org I can see people getting confused if the basedir changes on them.

v1.9.2 has baseDir determined if user hasn't specified.

[Bartvds]

This is cool!

Maybe make it a short dot file name? Like.baseDir.ts as ignoreBaseDirFile.ts is so bulky and regular.

[Bartvds]

When I use this I end up with a ignoreBaseDirFile.js.map, ignoreBaseDirFile.js and ignoreBaseDirFile.d.ts in my output directory.

Maybe we can delete those after compilation?

[basarat]

Like.baseDir.ts as ignoreBaseDirFile.ts is so bulky and regular.

My bad. I'll do .baseDir.d.ts and see how that goes (or revert to .baseDir.ts) . I'll put it in a minor version update (since the user options don't change).

---

Another Idea :
A better solution would be to figure out the correct outDir option based on the changed files e.g in the given sample above it can be js/foo. But that involves more work than I want to do right now. I'd rather wait and see typescript have a native baseDir option

[Bartvds]

Cool, all fine by me.

I'm not really using it explicitly (atm), just as-is with the fast option.

[basarat]

I'll do .baseDir.d.ts

a .d.ts does not play a role in determining the outDir inside the compiler (I sort of suspected that). Falling back to .baseDir.ts

[marcuswhit]

I'm a little confused. From the first post above, when I've set fast:always, I expected that your workaround would result in a JS folder tree that mirrors the TS tree (as it does when fast:never is set). But instead, I just get the following when I modify b.ts (newly generated files indicated):

ts
    a.ts
    foo
    |    .baseDir.ts [new]
    |    b.js [new]
    |    b.js.map [new]
    |    b.ts
    |    c.ts
js
    a.js
    foo
    |    b.js
    |    c.js

I was expecting the b.js file would be replaced in the JS file tree. What have I missed?

[basarat]

@marcuswhit baseDir (source) is only useful if an outDir (destination) is specified

[marcuswhit]

@basarat Ok, it seems with baseDir correctly set, the generated JS is placed in the correct target JS folder, but it's also created in the TS folder, as below. Given a full build doesn't create the extra js files in the TS folder, why does the fast compile do so?

ts
    .baseDir.ts [new]
    a.ts
    foo
    |    b.js [new]
    |    b.js.map [new]
    |    b.ts
    |    c.ts
js
    a.js
    foo
    |    b.js [new]
    |    b.js.map [new]
    |    c.js