Vendor dependencies

Let's see how I like this workflow.

vendor/wasm-bindgen/tests/headless/snippets.rs

@@ -0,0 +1,58 @@
+use wasm_bindgen::prelude::*;
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen(module = "/tests/headless/snippets1.js")]
+extern "C" {
+    fn get_two() -> u32;
+    #[wasm_bindgen(js_name = get_stateful)]
+    fn get_stateful1() -> u32;
+}
+
+#[wasm_bindgen(module = "/tests/headless/snippets1.js")]
+extern "C" {
+    #[wasm_bindgen(js_name = get_stateful)]
+    fn get_stateful2() -> u32;
+}
+
+#[wasm_bindgen_test]
+fn test_get_two() {
+    assert_eq!(get_two(), 2);
+}
+
+#[wasm_bindgen_test]
+fn stateful_deduplicated() {
+    assert_eq!(get_stateful1(), 1);
+    assert_eq!(get_stateful2(), 2);
+    assert_eq!(get_stateful1(), 3);
+    assert_eq!(get_stateful2(), 4);
+}
+
+#[wasm_bindgen(inline_js = "export function get_three() { return 3; }")]
+extern "C" {
+    fn get_three() -> u32;
+}
+
+#[wasm_bindgen_test]
+fn test_get_three() {
+    assert_eq!(get_three(), 3);
+}
+
+#[wasm_bindgen(inline_js = "let a = 0; export function get() { a += 1; return a; }")]
+extern "C" {
+    #[wasm_bindgen(js_name = get)]
+    fn duplicate1() -> u32;
+}
+
+#[wasm_bindgen(inline_js = "let a = 0; export function get() { a += 1; return a; }")]
+extern "C" {
+    #[wasm_bindgen(js_name = get)]
+    fn duplicate2() -> u32;
+}
+
+#[wasm_bindgen_test]
+fn duplicate_inline_not_unified() {
+    assert_eq!(duplicate1(), 1);
+    assert_eq!(duplicate2(), 1);
+    assert_eq!(duplicate1(), 2);
+    assert_eq!(duplicate2(), 2);
+}