Output directory messed up if tsc is triggered as VS Code task.

[vilicvane]

This only happens if tsc is executed via Code.

TypeScript Version:

nightly (1.9.0-dev.20160525-1.0)

Code

.vscode/tasks.json

{
    "version": "0.1.0",
    "command": "node", // Using npm scripts would result the same.
    "isShellCommand": true,
    "args": ["node_modules/typescript/lib/tsc.js"],
    "showOutput": "silent",
    "problemMatcher": "$tsc"
}

tsconfig.json

{
    "compilerOptions": {
        "module": "commonjs",
        "allowJs": true,
        "outDir": "bld",
        "rootDir": "src"
    },
    "exclude": [
        "node_modules",
        "bld"
    ]
}

src/foo/bar.ts

import '../biu/pia';

src/biu/pia.js

// Empty file.

Expected behavior:

Compiles correctly.

Actual behavior:

error TS5055: Cannot write file '.../src/biu/pia.js' because it would overwrite input file.

And if you put another .ts file and import it in src/foo.bar.ts, it would be output as .js file nested to its .ts source.

[Seikho]

Possibly related to microsoft/vscode#6719 ?

[mhegazy]

@zhengbli any thoughts?

[zhengbli]

Seems to be a VSCode task runner issue with node v6, the same as microsoft/vscode#6719. Running tsc from command line doesn't repro the error.

[Seikho]

The regression occurs in the cd1af12 commit.

[Seikho]

This (L590, program.ts) seems to be the offending change. It changes the capitalisation of the Windows drive letter (lower to upper in the case of microsoft/vscode#6719).

When run from the command line, the drive letter is already capitalised and stays capitalised.

[yortus]

Evidence that @Seikho has identified the problem.

[Seikho]

After further digging, it's a change from Node v5 to Node v6 in the behaviour of fs.realpath which is used in L547 sys.ts.

In node v5:

$ node
> process.version
'v5.11.1'
> require('fs').realpathSync('c:\\projects')
'c:\\projects'
>                                     

In node v6:

$ node
> process.version
'v6.2.0'
> require('fs').realpathSync('c:\\projects')
'C:\\projects'
>

[yortus]

@zhengbli could the 'external' tag be removed, and this be dealt with in TypeScript? See microsoft/vscode#6719 (comment).

EDIT: See also comment from node.js contributor about this: nodejs/node#6624 (comment)

[dbaeumer]

Important observations from microsoft/vscode#6719:

• make sure the symlink code works with drive letters created with subst as well. I have such a setup where I mapped C:\users\dirkb\projects => P:\ and this seems to fail with the latest build TS with wired error messages. See comment: Strange build behaviour building TypeScript from VSCode with Node v6 on Windows vscode#6719 (comment)
• there seems to be issue with drive letter in node 6.x: See On Windows, Node can be inconsistent in what case builtin functions use for drive letters nodejs/node#6624

[zhengbli]

@Seikho Thanks for the finding! The issue should be able to address from TypeScript side.

[dbaeumer]

@zhengbli shouldn't this be addressed in 2.0. It works in 1.8.x and is broken in @next. I am asking since it is tagged for 2.1

[yortus]

Fixing in @next would be great - We've had to disable the VSCode build task for all our affected projects since this surfaced, which is a minor hassle but still a hassle.