Improve types and docs of {import,export}SecretsBundle (#123)

* Improve return types of `{import,export}SecretsBundle`

* Improve documentation too

Author: richvdh

CHANGELOG.md

@@ -18,6 +18,9 @@
         keys that had been imported from key backup to be backed up again, when
         using the in-memory datastore.
 
+-   Improve the return types of `OlmMachine.{import,export}exportSecretsBundle()`.
+    ([#123](https://github.com/matrix-org/matrix-rust-sdk-crypto-wasm/pull/123))
+
 # matrix-sdk-crypto-wasm v4.10.0
 
 -   Expose new constructor function `OlmMachine.openWithKey()`.

src/machine.rs

@@ -534,7 +534,8 @@ impl OlmMachine {
         })
     }
 
-    /// Export all the secrets we have in the store into a [`SecretsBundle`].
+    /// Export all the secrets we have in the store into a {@link
+    /// SecretsBundle}.
     ///
     /// This method will export all the private cross-signing keys and, if
     /// available, the private part of a backup key and its accompanying
@@ -546,35 +547,29 @@ impl OlmMachine {
     /// **Warning**: Only export this and share it with a trusted recipient,
     /// i.e. if an existing device is sharing this with a new device.
     #[wasm_bindgen(js_name = "exportSecretsBundle")]
-    pub fn export_secrets_bundle(&self) -> Promise {
-        let me = self.inner.clone();
-
-        future_to_promise(async move {
-            Ok(me.store().export_secrets_bundle().await.map(store::SecretsBundle::from)?)
-        })
+    pub async fn export_secrets_bundle(&self) -> Result<store::SecretsBundle, JsError> {
+        Ok(self.inner.store().export_secrets_bundle().await?.into())
     }
 
-    /// Import and persists secrets from a [`SecretsBundle`].
+    /// Import and persists secrets from a {@link SecretsBundle}.
     ///
     /// This method will import all the private cross-signing keys and, if
     /// available, the private part of a backup key and its accompanying
     /// version into the store.
     ///
     /// **Warning**: Only import this from a trusted source, i.e. if an existing
     /// device is sharing this with a new device. The imported cross-signing
-    /// keys will create a [`OwnUserIdentity`] and mark it as verified.
+    /// keys will create a {@link OwnUserIdentity} and mark it as verified.
     ///
     /// The backup key will be persisted in the store and can be enabled using
-    /// the [`BackupMachine`].
+    /// the {@link BackupMachine}.
+    ///
+    /// The provided `SecretsBundle` is freed by this method; be careful not to
+    /// use it once this method has been called.
     #[wasm_bindgen(js_name = "importSecretsBundle")]
-    pub fn import_secrets_bundle(&self, bundle: store::SecretsBundle) -> Promise {
-        let me = self.inner.clone();
-
-        future_to_promise(async move {
-            me.store().import_secrets_bundle(&bundle.inner).await?;
-
-            Ok(JsValue::null())
-        })
+    pub async fn import_secrets_bundle(&self, bundle: store::SecretsBundle) -> Result<(), JsError> {
+        self.inner.store().import_secrets_bundle(&bundle.inner).await?;
+        Ok(())
     }
 
     /// Export all the private cross signing keys we have.