Is there a demo for transform plugin with tests

[chenjun1011]

I init a plugin project followed the doc Implementing a plugin . But having some trouble when writing test for this plugin.

It should how to mock the parameter for the transform plugin，such as program and _metadata in the test case.

#[plugin_transform]
pub fn process_transform(program: Program, _metadata: TransformPluginProgramMetadata) -> Program {
    program.fold_with(&mut as_folder(TransformVisitor))
}

Test for typescript type stripper in the doc seems no need to deal with this problem.

So is there any demo with test for the plugin inited by swc_cli. It seems hard to debug the plugin in rust without a test as an entry.

[chenjun1011]

Finally got the demo working:

https://github.com/chenjun1011/swc-plugin-demo

There are some points need pay attention, when followed the doc to create a new plugin.

1. Compiler Error:

use swc_plugin::ast::*;
use swc_plugin::util::swc_common::Spanned;

impl VisitMut for TransformVisitor {
    fn visit_mut_bin_expr(&mut self, e: &mut BinExpr) {
        e.visit_mut_children_with(self);

        if e.op == op!("===") {
-            e.left = Ident::new("kdy1".into(), e.left.span()).into();
+            e.left = Box::new(Expr::Ident(Ident::new("kdy1".into(), e.left.span()).into()));
        }
    }
}

2. Compiler error when use the latest swc_plugin(0.73.0), 0.71.0 is ok.

3. Need add rlib to crate-type to make test work

[lib]
bench = false
- crate-type = ["cdylib"]
+ crate-type = ["cdylib", "rlib"]