[swc plugin] The handler.struct_span_warn does not emit warnings if the plugin transform completes without errors

[gaoachao]

Describe the bug

How to run the demo

demo: https://github.com/gaoachao/swc-plugin-demo

pnpm install
pnpm run build
npx swc ./index.js

Current behavior

• When the transform is successful, warnings are not printed.
• When there is an error during the transform, warnings are printed.

Expected behavior

When npx swc index.js succeeds, warnings should still be printed in the terminal.

How to Reproduce the Issue

Here is my code, and no warnings are printed.

"createSelectorQuery" => {
    HANDLER.with(|handler| {
        handler
            .struct_span_warn(
                n.span,
                format!(
                    "WARNING: {} is deprecated.",
                    id.sym.to_string()
                )
                .as_str(),
            )
            .emit()
    });
}
"getElementById" => {
    HANDLER.with(|handler| {
        handler
            .struct_span_warn(
                n.span,
                format!(
                    "WARNING: {} is deprecated.",
                    id.sym.to_string()
                )
                .as_str(),
            )
            .emit()
    });
}

If I change one of the struct_span_warn calls to struct_span_err, both warnings and errors will be printed on the terminal.

"createSelectorQuery" => {
    HANDLER.with(|handler| {
        handler
            .struct_span_err(
                n.span,
                format!(
                    "WARNING: {} is deprecated.",
                    id.sym.to_string()
                )
                .as_str(),
            )
            .emit()
    });
}
"getElementById" => {
    HANDLER.with(|handler| {
        handler
            .struct_span_warn(
                n.span,
                format!(
                    "WARNING: {} is deprecated.",
                    id.sym.to_string()
                )
                .as_str(),
            )
            .emit()
    });
}

Input code

this.createSelectorQuery();
this.getElementById();

Config

{
  "$schema": "https://swc.rs/schema.json",
  "isModule": true,
  "jsc": {
    "parser": {
      "syntax": "ecmascript"
    },
    "target": "es2022",
    "experimental": {
      "plugins": [["./my_first_plugin.wasm", {}]]
    }
  }
}

Playground link (or link to the minimal reproduction)

https://github.com/gaoachao/swc-plugin-demo

SWC Info output

No response

Expected behavior

When the transform is successful, warnings should still be printed in the terminal.

Actual behavior

No response

Version

swc_core = { version = "9.0.*", features = ["ecma_plugin_transform"] }

Additional context

No response