serializable structured errors

src-tauri/src/errors.rs

@@ -1,3 +1,7 @@
+use std::error::Error;
+use std::convert::AsRef;
+use strum_macros::AsRefStr;
+
 use thiserror::Error as ThisError;
 
 use aws_sdk_sts::{
@@ -10,35 +14,70 @@ use sqlx::{
 };
 
 use serde::{Serialize, Serializer, ser::SerializeMap};
-use strum_macros::IntoStaticStr;
 
 
-pub struct SerializeError<E> {
-    pub err: E
-}
+// pub struct SerializeError<E> {
+//     pub err: E,
+// }
 
-impl<E: std::error::Error> Serialize for SerializeError<E>
+// impl<E: std::error::Error> Serialize for SerializeError<E>
+// {
+//     fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+//         let mut map = serializer.serialize_map(None)?;
+//         map.serialize_entry("msg", &format!("{}", self.err))?;
+//         if let Some(src) = self.err.source() {
+//             let ser_src = SerializeError { err: src };
+//             map.serialize_entry("source", &ser_src)?;
+//         }
+//         map.end()
+//     }
+// }
+
+// impl<E: std::error::Error> From<E> for SerializeError<E> {
+//     fn from(err: E) -> Self {
+//         SerializeError { err }
+//     }
+// }
+
+
+fn serialize_basic_err<E, S>(err: &E, serializer: S) -> Result<S::Ok, S::Error>
+where
+    E: std::error::Error + AsRef<str>,
+    S: Serializer,
 {
-    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-        let mut map = serializer.serialize_map(None)?;
-        map.serialize_entry("msg", &format!("{}", self.err))?;
-        if let Some(src) = self.err.source() {
-            let ser_src = SerializeError { err: src };
-            map.serialize_entry("source", &ser_src)?;
-        }
-        map.end()
+    let mut map = serializer.serialize_map(None)?;
+    map.serialize_entry("code", err.as_ref())?;
+    map.serialize_entry("msg", &format!("{err}"))?;
+    if let Some(src) = err.source() {
+        map.serialize_entry("source", &format!("{src}"))?;
     }
+    map.end()
 }
 
-impl<E: std::error::Error> From<E> for SerializeError<E> {
-    fn from(err: E) -> Self {
-        SerializeError { err }
+
+fn serialize_upstream_err<E, M>(err: &E, map: &mut M) -> Result<(), M::Error> 
+where
+    E: Error,
+    M: serde::ser::SerializeMap,
+{
+    let src = err.source().map(|s| format!("{s}"));
+    map.serialize_entry("source", &src)
+}
+
+
+macro_rules! impl_serialize_basic {
+    ($err_type:ident) => {
+        impl Serialize for $err_type {
+            fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+                serialize_basic_err(self, serializer)
+            }
+        }
     }
 }
 
 
 // error during initial setup (primarily loading state from db)
-#[derive(Debug, ThisError)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum SetupError {
     #[error("Invalid database record")]
     InvalidRecord, // e.g. wrong size blob for nonce or salt
@@ -52,7 +91,7 @@ pub enum SetupError {
 
 
 // error when attempting to tell a request handler whether to release or deny credentials
-#[derive(Debug, ThisError, IntoStaticStr)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum SendResponseError {
     #[error("The specified credentials request was not found")]
     NotFound, // no request with the given id
@@ -62,7 +101,7 @@ pub enum SendResponseError {
 
 
 // errors encountered while handling an HTTP request
-#[derive(Debug, ThisError)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum RequestError {
     #[error("Error writing to stream: {0}")]
     StreamIOError(#[from] std::io::Error),
@@ -82,7 +121,7 @@ pub enum RequestError {
 }
 
 
-#[derive(Debug, ThisError)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum GetCredentialsError {
     #[error("Credentials are currently locked")]
     Locked,
@@ -91,7 +130,7 @@ pub enum GetCredentialsError {
 }
 
 
-#[derive(Debug, ThisError)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum GetSessionError {
     #[error("Request completed successfully but no credentials were returned")]
     NoCredentials, // SDK returned successfully but credentials are None
@@ -100,7 +139,7 @@ pub enum GetSessionError {
 }
 
 
-#[derive(Debug, ThisError)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum UnlockError {
     #[error("App is not locked")]
     NotLocked,
@@ -118,10 +157,87 @@ pub enum UnlockError {
 
 
 // Errors encountered while trying to figure out who's on the other end of a request
-#[derive(Debug, ThisError)]
+#[derive(Debug, ThisError, AsRefStr)]
 pub enum ClientInfoError {
     #[error("Found PID for client socket, but no corresponding process")]
     ProcessNotFound,
     #[error("Couldn't get client socket details: {0}")]
     NetstatError(#[from] netstat2::error::Error),
 }
+
+
+// =========================
+// Serialize implementations
+// =========================
+
+
+struct SerializeWrapper<E>(pub E);
+
+impl Serialize for SerializeWrapper<&GetSessionTokenError> {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let err = self.0;
+        let mut map = serializer.serialize_map(None)?;
+        map.serialize_entry("code", &err.code())?;
+        map.serialize_entry("msg", &err.message())?;
+        map.serialize_entry("source", &None::<&str>)?;
+        map.end()
+    }
+}
+
+
+
+impl_serialize_basic!(SetupError);
+impl_serialize_basic!(SendResponseError);
+impl_serialize_basic!(GetCredentialsError);
+impl_serialize_basic!(ClientInfoError);
+
+
+impl Serialize for RequestError {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let mut map = serializer.serialize_map(None)?;
+        map.serialize_entry("code", self.as_ref())?;
+        map.serialize_entry("msg", &format!("{self}"))?;
+
+        match self {
+            RequestError::NoCredentials(src) => map.serialize_entry("source", &src)?,
+            RequestError::ClientInfo(src) => map.serialize_entry("source", &src)?,
+            _ => serialize_upstream_err(self, &mut map)?,
+        }
+
+        map.end()
+    }
+}
+
+
+impl Serialize for GetSessionError {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let mut map = serializer.serialize_map(None)?;
+        map.serialize_entry("code", self.as_ref())?;
+        map.serialize_entry("msg", &format!("{self}"))?;
+
+        match self {
+            GetSessionError::SdkError(AwsSdkError::ServiceError(se_wrapper)) => {
+                let err = se_wrapper.err();
+                map.serialize_entry("source", &SerializeWrapper(err))?
+            }
+            _ => serialize_upstream_err(self, &mut map)?,
+        }
+
+        map.end()
+    }
+}
+
+
+impl Serialize for UnlockError {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let mut map = serializer.serialize_map(None)?;
+        map.serialize_entry("code", self.as_ref())?;
+        map.serialize_entry("msg", &format!("{self}"))?;
+
+        match self {
+            UnlockError::GetSession(src) => map.serialize_entry("source", &src)?,
+            _ => serialize_upstream_err(self, &mut map)?,
+        }
+        map.end()
+    }
+}

src-tauri/src/ipc.rs

@@ -36,10 +36,8 @@ pub fn respond(response: RequestResponse, app_state: State<'_, AppState>) -> Res
 
 
 #[tauri::command]
-pub async fn unlock(passphrase: String, app_state: State<'_, AppState>) -> Result<(), SerializeError<UnlockError>> {
-    app_state.decrypt(&passphrase)
-        .await
-        .map_err(|e| SerializeError::from(e))
+pub async fn unlock(passphrase: String, app_state: State<'_, AppState>) -> Result<(), UnlockError> {
+    app_state.decrypt(&passphrase).await
 }
 
 
@@ -59,10 +57,8 @@ pub async fn save_credentials(
     credentials: Credentials,
     passphrase: String,
     app_state: State<'_, AppState>
-) -> Result<(), SerializeError<UnlockError>> {
-    app_state.save_creds(credentials, &passphrase)
-        .await
-        .map_err(|e| SerializeError::from(e))
+) -> Result<(), UnlockError> {
+    app_state.save_creds(credentials, &passphrase).await
 }
 
 

src/views/EnterCredentials.svelte

@@ -1,41 +1,42 @@
 <script>
     import { onMount, createEventDispatcher } from 'svelte';
     import { invoke } from '@tauri-apps/api/tauri';
+    import { getRootCause } from '../lib/errors.js';
 
     export let appState;
 
     const dispatch = createEventDispatcher();
-    let error = null;
+    let errorMsg = null;
     let AccessKeyId, SecretAccessKey, passphrase
 
     async function save() {
+        console.log('Saving credentials.');
+        let credentials = {AccessKeyId, SecretAccessKey};
+
         try {
-            console.log('Saving credentials.');
-            let credentials = {AccessKeyId, SecretAccessKey};
-
-            try {
-                await invoke('save_credentials', {credentials, passphrase});
-                if (appState.currentRequest) {
-                    dispatch('navigate', {target: 'ShowApproved'})
-                }
-                else {
-                    dispatch('navigate', {target: 'Home'})
-                }
+            await invoke('save_credentials', {credentials, passphrase});
+            if (appState.currentRequest) {
+                dispatch('navigate', {target: 'ShowApproved'})
             }
-            catch (e) {
-                error = e;
-                window.error = e;
+            else {
+                dispatch('navigate', {target: 'Home'})
             }
-
         }
         catch (e) {
-            console.log("Error saving credentials:", e);
+            window.error = e;
+            if (e.code === "GetSession") {
+                let root = getRootCause(e);
+                errorMsg = `Error response from AWS (${root.code}): ${root.msg}`;
+            }
+            else {
+                errorMsg = e.msg;
+            }
         }
     }
 </script>
 
-{#if error}
-    <div class="text-red-400">{error}</div>
+{#if errorMsg}
+    <div class="text-red-400">{errorMsg}</div>
 {/if}
 
 <form action="#" on:submit|preventDefault="{save}">

src/views/Unlock.svelte

@@ -1,13 +1,14 @@
 <script>
     import { invoke } from '@tauri-apps/api/tauri';
     import { createEventDispatcher } from 'svelte';
+    import { getRootCause } from '../lib/errors.js';
     import Button from '../ui/Button.svelte';
 
     export let appState;
 
     const dispatch = createEventDispatcher();
 
-    let error = null;
+    let errorMsg = null;
     let passphrase = '';
     async function unlock() {
         console.log('invoking unlock command.')
@@ -23,14 +24,20 @@
             }
         }
         catch (e) {
-            error = e;
             window.error = e;
+            if (e.code === 'GetSession') {
+                let root = getRootCause(e);
+                errorMsg = `Error response from AWS (${root.code}): ${root.msg}`;
+            }
+            else {
+                errorMsg = e.msg;
+            }
         }
     }
 </script>
 
-{#if error}
-    <div class="text-red-400">{error}</div>
+{#if errorMsg}
+    <div class="text-red-400">{errorMsg}</div>
 {/if}
 
 <form action="#" on:submit|preventDefault="{unlock}">