Empty input prompt when 'login'

[danwilhelm]

🐛 Bug description

wasm-pack login gives the appearance that the program is hanging or not working. It does not display stdout/stderr to the user. Instead of asking for a username, the user only sees the cursor.

🤔 Expected Behavior

wasm-pack login spawns npm adduser and should behave identically. The user should see the following line-by-line interactive prompt:

Username:
Password:
Email: (this IS public)

Errors should also be displayed. For example, if an email address is entered not containing '@', the user should see "npm WARN Email must be an email address" followed by a repeated Email prompt.

👟 Steps to reproduce

1. In a non-Windows OS, run: wasm-pack login
2. Now, the program will indefinitely wait for input without prompting the user what to do.
3. After Ctrl-C is pressed, buffered output is displayed to the screen.

🌍 Your environment

wasm-pack version: 0.5.1 (also fails on latest master branch)
rustc version: rustc 1.33.0-nightly (8e2063d02 2019-01-07)

🔧 Technical explanation

wasm-pack login spawns npm adduser, which displays an interactive prompt, asking the user for username/password/email. PR #392 inadvertantly replaced the interactive process spawner with child::run, which is hard-coded to buffer stdout/stderr. This caused login to become essentially unusable; the user can no longer see interactive input prompts or error messages.

The above can be tested directly:

1. In a non-Windows OS, run: wasm-pack login
2. Enter asdf and press Enter. (Username)
3. Enter asdf and press Enter. (Password)
4. Enter asdf@asdf.com and press Enter. (Email)
5. Because the child process now is complete, all buffered output should be displayed to the screen.

[ashleygwilliams]

closed by #487