fix(create-neon): Render diagnostics to stderr in cargo build

[kjvalencik]

Currently, create-neon uses --message-format=json which outputs diagnostics (e.g., compile errors) to stdout in JSON metadata. This makes it difficult to see compiler errors. For example, I have started with the out-of-the-box Neon app and changed the return type of hello to be JsNumber.

$ npm run build

> [email protected] build
> npm run cargo-build -- --release


> [email protected] cargo-build
> cargo build --message-format=json > cargo.log --release

   Compiling example v0.1.0 (/private/tmp/example)
error: could not compile `example` (lib) due to 2 previous errors

The error message does not show. If I change to --message-format=json-render-diagnostics, artifacts will still be sent to stdout, but compile errors will be rendered in human readable form on stderr.

$ npm run build

> [email protected] build
> npm run cargo-build -- --release


> [email protected] cargo-build
> cargo build --message-format=json-render-diagnostics > cargo.log --release

   Compiling example v0.1.0 (/private/tmp/example)
error[E0308]: mismatched types
   --> src/lib.rs:4:8
    |
4   |     Ok(cx.string("hello node"))
    |     -- ^^^^^^^^^^^^^^^^^^^^^^^ expected `Handle<'_, JsNumber>`, found `Handle<'_, JsString>`
    |     |
    |     arguments to this enum variant are incorrect
    |
    = note: expected struct `Handle<'_, neon::prelude::JsNumber>`
               found struct `Handle<'_, JsString>`

[dherman]

Thank you for explaining this -- I hadn't quite understood the difference between --json and --json-render-diagnostics. This is definitely better.

[dherman]

Published to the registry at [email protected]! 🚀