Remove __exports map on the web target

This is no longe rneeded now that we precisely track what needs to be
exported for an imported item, so all the imports are hooked up
correctly elsewhere without the need for the `__exports` map.

Author: alexcrichton

crates/cli-support/src/js/mod.rs

@@ -142,7 +142,8 @@ impl<'a> Context<'a> {
             OutputMode::Bundler { .. }
             | OutputMode::Node {
                 experimental_modules: true,
-            } => {
+            }
+            | OutputMode::Web => {
                 if contents.starts_with("function") {
                     let body = &contents[8..];
                     if export_name == definition_name {
@@ -161,50 +162,6 @@ impl<'a> Context<'a> {
                     format!("export const {} = {};\n", export_name, contents)
                 }
             }
-            OutputMode::Web => {
-                // In web mode there's no need to export the internals of
-                // wasm-bindgen as we're not using the module itself as the
-                // import object but rather the `__exports` map we'll be
-                // initializing below.
-                let export = if export_name.starts_with("__wbindgen")
-                    || export_name.starts_with("__wbg_")
-                    || export_name.starts_with("__widl_")
-                {
-                    ""
-                } else {
-                    "export "
-                };
-                if contents.starts_with("function") {
-                    let body = &contents[8..];
-                    if export_name == definition_name {
-                        format!(
-                            "{}function {name}{}\n__exports.{name} = {name}",
-                            export,
-                            body,
-                            name = export_name,
-                        )
-                    } else {
-                        format!(
-                            "{}function {defname}{}\n__exports.{name} = {defname}",
-                            export,
-                            body,
-                            name = export_name,
-                            defname = definition_name,
-                        )
-                    }
-                } else if contents.starts_with("class") {
-                    assert_eq!(export_name, definition_name);
-                    format!("{}{}\n", export, contents)
-                } else {
-                    assert_eq!(export_name, definition_name);
-                    format!(
-                        "{}const {name} = {};\n__exports.{name} = {name};",
-                        export,
-                        contents,
-                        name = export_name
-                    )
-                }
-            }
         };
         self.global(&global);
         Ok(())
@@ -366,7 +323,6 @@ impl<'a> Context<'a> {
             // expose the same initialization function as `--target no-modules`
             // as the default export of the module.
             OutputMode::Web => {
-                self.imports_post.push_str("const __exports = {};\n");
                 self.imports_post.push_str("let wasm;\n");
                 init = self.gen_init(needs_manual_start);
                 footer.push_str("export default init;\n");