fix: Work around anyhow::msg not having a proper Debug::fmt (#344)

The generic `anyhow::msg` will just `Debug::fmt` the `String` that you feed
it, which results in Error types with leading quotes.

Author: Swatinem

sentry-core/src/error.rs

@@ -98,8 +98,21 @@ pub fn event_from_error<E: Error + ?Sized>(err: &E) -> Event<'static> {
 
 fn exception_from_error<E: Error + ?Sized>(err: &E) -> Exception {
     let dbg = format!("{:?}", err);
+    let value = err.to_string();
+
+    // A generic `anyhow::msg` will just `Debug::fmt` the `String` that you feed
+    // it. Trying to parse the type name from that will result in a leading quote
+    // and the first word, so quite useless.
+    // To work around this, we check if the `Debug::fmt` of the complete error
+    // matches its `Display::fmt`, in which case there is no type to parse and
+    // we will just be using `Error`.
+    let ty = if dbg == format!("{:?}", value) {
+        String::from("Error")
+    } else {
+        parse_type_from_debug(&dbg).to_owned()
+    };
     Exception {
-        ty: parse_type_from_debug(&dbg).to_owned(),
+        ty,
         value: Some(err.to_string()),
         ..Default::default()
     }
@@ -146,3 +159,14 @@ fn test_parse_type_from_debug() {
     );
     assert_eq!(parse(&err), "ParseIntError");
 }
+
+#[test]
+fn test_parse_anyhow_as_error() {
+    let anyhow_err = anyhow::anyhow!("Ooops, something bad happened");
+    let err: &dyn Error = anyhow_err.as_ref();
+
+    let exc = exception_from_error(err);
+
+    assert_eq!(&exc.ty, "Error");
+    assert_eq!(exc.value.as_deref(), Some("Ooops, something bad happened"));
+}