make wasm-bindgen-test-runner easier to expand

crates/cli/src/bin/wasm-bindgen-test-runner/main.rs

@@ -27,6 +27,12 @@ mod node;
 mod server;
 mod shell;
 
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+enum TestMode {
+    Node,
+    Browser,
+}
+
 fn main() -> anyhow::Result<()> {
     env_logger::init();
     let mut args = env::args_os().skip(1);
@@ -81,14 +87,20 @@ fn main() -> anyhow::Result<()> {
     // That's done on a per-test-binary basis with the
     // `wasm_bindgen_test_configure` macro, which emits a custom section for us
     // to read later on.
-    let mut node = true;
-    if let Some(section) = wasm.customs.remove_raw("__wasm_bindgen_test_unstable") {
-        node = !section.data.contains(&0x01);
-    }
+
+    let custom_section = wasm.customs.remove_raw("__wasm_bindgen_test_unstable");
+    let test_mode = match custom_section {
+        Some(section) if section.data.contains(&0x01) => TestMode::Browser,
+        Some(_) => bail!("invalid __wasm_bingen_test_unstable value"),
+        None => TestMode::Node,
+    };
+
     let headless = env::var("NO_HEADLESS").is_err();
     let debug = env::var("WASM_BINDGEN_NO_DEBUG").is_err();
 
     // Gracefully handle requests to execute only node or only web tests.
+    let node = test_mode == TestMode::Node;
+
     if env::var_os("WASM_BINDGEN_TEST_ONLY_NODE").is_some() {
         if !node {
             println!(
@@ -131,9 +143,12 @@ integration test.\
     // Make the generated bindings available for the tests to execute against.
     shell.status("Executing bindgen...");
     let mut b = Bindgen::new();
+    match test_mode {
+        TestMode::Node => b.nodejs(true)?,
+        TestMode::Browser => b.web(true)?,
+    };
+
     b.debug(debug)
-        .nodejs(node)?
-        .web(!node)?
         .input_module(module, wasm)
         .keep_debug(false)
         .emit_start(false)
@@ -141,13 +156,11 @@ integration test.\
         .context("executing `wasm-bindgen` over the wasm file")?;
     shell.clear();
 
-    // If we're executing in node.js, that module will take it from here.
-    if node {
-        return node::execute(&module, &tmpdir, &args.collect::<Vec<_>>(), &tests);
-    }
+    let args: Vec<_> = args.collect();
 
-    // Otherwise we're executing in a browser. Spawn a server which serves up
-    // the local generated files over an HTTP server.
+    match test_mode {
+        TestMode::Node => node::execute(&module, &tmpdir, &args, &tests)?,
+        TestMode::Browser => {
             let srv = server::spawn(
                 &if headless {
                     "127.0.0.1:0".parse().unwrap()
@@ -157,7 +170,7 @@ integration test.\
                 headless,
                 &module,
                 &tmpdir,
-        &args.collect::<Vec<_>>(),
+                &args,
                 &tests,
             )
             .context("failed to spawn server")?;
@@ -180,5 +193,7 @@ integration test.\
 
             thread::spawn(|| srv.run());
             headless::run(&addr, &shell, timeout)?;
+        }
+    }
     Ok(())
 }