finish implementing Cursor API

Author: Ekleog

src/cursor.rs

@@ -2,7 +2,8 @@ use crate::{
     transaction::transaction_request,
     utils::{
         map_cursor_advance_err, map_cursor_advance_until_err,
-        map_cursor_advance_until_primary_key_err, map_cursor_delete_err, slice_to_array,
+        map_cursor_advance_until_primary_key_err, map_cursor_delete_err, map_cursor_update_err,
+        slice_to_array,
     },
 };
 use std::marker::PhantomData;
@@ -151,12 +152,26 @@ impl<Err> Cursor<Err> {
     /// Note that this method does not work on key-only cursors over indexes.
     ///
     /// Internally, this uses [`IDBCursor::delete`](https://developer.mozilla.org/en-US/docs/Web/API/IDBCursor/delete).
-    pub async fn delete(&mut self) -> crate::Result<(), Err> {
+    pub async fn delete(&self) -> crate::Result<(), Err> {
         let Some(sys) = &self.sys else {
             return Err(crate::Error::CursorCompleted);
         };
         let req = sys.delete().map_err(map_cursor_delete_err)?;
         transaction_request(req).await?;
         Ok(())
     }
+
+    /// Update the value currently pointed by this [`Cursor`] to `value`
+    ///
+    /// Note that this method does not work on key-only cursors over indexes.
+    ///
+    /// Internally, this uses [`IDBCursor::update`](https://developer.mozilla.org/en-US/docs/Web/API/IDBCursor/update).
+    pub async fn update(&self, value: &JsValue) -> crate::Result<(), Err> {
+        let Some(sys) = &self.sys else {
+            return Err(crate::Error::CursorCompleted);
+        };
+        let req = sys.update(value).map_err(map_cursor_update_err)?;
+        transaction_request(req).await?;
+        Ok(())
+    }
 }

src/utils.rs

@@ -174,6 +174,19 @@ pub(crate) fn map_cursor_delete_err<Err>(err: JsValue) -> crate::Error<Err> {
     }
 }
 
+pub(crate) fn map_cursor_update_err<Err>(err: JsValue) -> crate::Error<Err> {
+    match error_name!(&err) {
+        Some("InvalidStateError") => crate::Error::CursorCompleted,
+        Some("TransactionInactiveError") => {
+            panic!("Tried advancing a Cursor on an ObjectStore while the transaction was inactive")
+        }
+        Some("ReadOnlyError") => crate::Error::ReadOnly,
+        Some("DataError") => crate::Error::InvalidKey,
+        Some("DataCloneError") => crate::Error::FailedClone,
+        _ => crate::Error::from_js_value(err),
+    }
+}
+
 fn bound_map<T, U>(b: Bound<T>, f: impl FnOnce(T) -> U) -> Bound<U> {
     // TODO: replace with Bound::map once https://github.com/rust-lang/rust/issues/86026 is stable
     match b {

tests/js.rs

@@ -197,6 +197,7 @@ async fn smoke_test() {
             let mut cursor = stuffs.cursor().open().await.unwrap();
             while let Some(val) = cursor.value() {
                 all.push(val);
+                cursor.delete().await.unwrap();
                 cursor.advance(1).await.unwrap();
             }
             assert_eq!(
@@ -207,6 +208,7 @@ async fn smoke_test() {
                     (**JsString::from("value1")).clone()
                 ]
             );
+            assert_eq!(stuffs.count().await.unwrap(), 0);
 
             Ok(())
         })