Breaking changes for Bun 1.2

[Electroid]

This is a tracking issue for behaviour changes we want to introduce in Bun 1.2.

• https://github.com/oven-sh/bun/issues/12180

[paperclover]

should we consider https://github.com/oven-sh/bun/issues/4464

[paperclover]

there are some existing breaking changes behind compile time feature flags. these can be inspected by doing a code search for breaking_changes_1_2

• websocket server: ws.subscribe() function will require a string argument
• bundler: --sourcemap without an argument is going to default to linked instead of inline
• bundler: imports marked external with a second argument will no longer hide that second value (this is done for some backwards compatibility that i want to remove)

[paperclover]

logging this here

• make Bun.build a rejected promise on failure. people continue to run into this footgun that a failing build returns an object with success: false, especially when examples do not check the success code.

[dylan-conway]

Another change we should consider: bun -p shorthand for --print. Currently it is --port. https://github.com/oven-sh/bun/issues/14223

[RiskyMH]

• https://github.com/oven-sh/bun/issues/8125 "what this needs is --env-prefix so you can do the --env-prefix=VITE_PUBLIC_"

[RiskyMH]

Consider making custom inspect function exception's better

Context:

When a custom inspect function threw an exception, Bun would return [native code]. This was confusing. We wish we could change this to throw an error, but that would be a breaking change. Instead, we've made it print [custom formatter threw an exception] instead, which is slightly better but not what we'd prefer. In a future version of Bun, we will change this to throw an error but we do not want your code to potentially randomly break in a minor version update. https://bun.sh/blog/bun-v1.1.7#fixed-custom-inspect-exception

Edit: this is already fixed in https://github.com/oven-sh/bun/pull/16009

[paperclover]

• Bun.build will add the condition "development" when NODE_ENV is not development. This allows esm-env (used by svelte) to use the correct variable. Bake already does this.

[Electroid]

See what we changed in Bun 1.2.