Throw TypeErrors instead of strings on parser errors

Author: mrbbot

src/lib.rs

@@ -86,7 +86,11 @@ trait IntoJsResult<T> {
 impl<T, E: ToString> IntoJsResult<T> for Result<T, E> {
     #[inline]
     fn into_js_result(self) -> JsResult<T> {
-        self.map_err(|e| JsValue::from(e.to_string()))
+        self.map_err(|e| {
+            let mut msg = String::from("Parser error: ");
+            msg.push_str(&e.to_string());
+            TypeError::new(&msg).into()
+        })
     }
 }
 

test/element.spec.ts

@@ -257,3 +257,16 @@ test("uses last end tag handler", async (t) => {
     .transform("<p>test</p>");
   t.is(res, "<p>test2</p>");
 });
+test("throws error on no end tag", async (t) => {
+  const res = new HTMLRewriter()
+    .on("img", {
+      element(element) {
+        element.onEndTag(() => t.fail());
+      },
+    })
+    .transform('<img src="" alt="">');
+  await t.throwsAsync(res, {
+    instanceOf: TypeError,
+    message: "Parser error: No end tag.",
+  });
+});

test/selectors.spec.ts

@@ -153,10 +153,9 @@ test("throws error on unsupported selector", async (t) => {
       },
     })
     .transform("<p>old</p>");
-  // Cannot use t.throwsAsync here as promise rejects with string not error type
-  try {
-    await res;
-  } catch (e) {
-    t.is(e, "Unsupported pseudo-class or pseudo-element in selector.");
-  }
+  await t.throwsAsync(res, {
+    instanceOf: TypeError,
+    message:
+      "Parser error: Unsupported pseudo-class or pseudo-element in selector.",
+  });
 });