securejoin: replace thiserror with anyhow

Refactoring to reduce the number of custom error types.

CHANGELOG.md

@@ -3,7 +3,7 @@
 ## Unreleased
 
 ### Changes
-- refactorings #3354 #3347 #3353
+- refactorings #3354 #3347 #3353 #3346
 
 ### Fixes
 - do not unnecessarily SELECT folders if there are no operations planned on

src/securejoin.rs

@@ -137,27 +137,13 @@ async fn get_self_fingerprint(context: &Context) -> Option<Fingerprint> {
     }
 }
 
-#[derive(Debug, thiserror::Error)]
-pub enum JoinError {
-    #[error("Failed to send handshake message: {0}")]
-    SendMessage(#[from] SendMsgError),
-
-    // Note that this can currently only occur if there is a bug in the QR/Lot code as this
-    // is supposed to create a contact for us.
-    #[error("Unknown contact (this is a bug): {0}")]
-    UnknownContact(#[source] anyhow::Error),
-
-    #[error("Other")]
-    Other(#[from] anyhow::Error),
-}
-
 /// Take a scanned QR-code and do the setup-contact/join-group/invite handshake.
 ///
 /// This is the start of the process for the joiner.  See the module and ffi documentation
 /// for more details.
 ///
 /// The function returns immediately and the handshake will run in background.
-pub async fn dc_join_securejoin(context: &Context, qr: &str) -> Result<ChatId, JoinError> {
+pub async fn dc_join_securejoin(context: &Context, qr: &str) -> Result<ChatId> {
     securejoin(context, qr).await.map_err(|err| {
         warn!(context, "Fatal joiner error: {:#}", err);
         // The user just scanned this QR code so has context on what failed.
@@ -166,7 +152,7 @@ pub async fn dc_join_securejoin(context: &Context, qr: &str) -> Result<ChatId, J
     })
 }
 
-async fn securejoin(context: &Context, qr: &str) -> Result<ChatId, JoinError> {
+async fn securejoin(context: &Context, qr: &str) -> Result<ChatId> {
     /*========================================================
     ====             Bob - the joiner's side             =====
     ====   Step 2 in "Setup verified contact" protocol   =====
@@ -180,14 +166,6 @@ async fn securejoin(context: &Context, qr: &str) -> Result<ChatId, JoinError> {
     bob::start_protocol(context, invite).await
 }
 
-/// Error when failing to send a protocol handshake message.
-///
-/// Wrapping the [anyhow::Error] means we can "impl From" more easily on errors from this
-/// function.
-#[derive(Debug, thiserror::Error)]
-#[error("Failed sending handshake message")]
-pub struct SendMsgError(#[from] anyhow::Error);
-
 /// Send handshake message from Alice's device;
 /// Bob's handshake messages are sent in `BobState::send_handshake_message()`.
 async fn send_alice_handshake_msg(
@@ -195,7 +173,7 @@ async fn send_alice_handshake_msg(
     contact_id: ContactId,
     step: &str,
     fingerprint: Option<Fingerprint>,
-) -> Result<(), SendMsgError> {
+) -> Result<()> {
     let mut msg = Message {
         viewtype: Viewtype::Text,
         text: Some(format!("Secure-Join: {}", step)),
@@ -353,7 +331,8 @@ pub(crate) async fn handle_securejoin_handshake(
                 &format!("{}-auth-required", &step[..2]),
                 None,
             )
-            .await?;
+            .await
+            .context("failed sending auth-required handshake message")?;
             Ok(HandshakeMessage::Done)
         }
         "vg-auth-required" | "vc-auth-required" => {
@@ -481,7 +460,8 @@ pub(crate) async fn handle_securejoin_handshake(
                     "vc-contact-confirm",
                     Some(fingerprint),
                 )
-                .await?;
+                .await
+                .context("failed sending vc-contact-confirm message")?;
 
                 inviter_progress!(context, contact_id, 1000);
             }

src/securejoin/bob.rs

@@ -3,7 +3,7 @@
 //! This are some helper functions around [`BobState`] which augment the state changes with
 //! the required user interactions.
 
-use anyhow::Result;
+use anyhow::{Context as _, Result};
 
 use crate::chat::{is_contact_in_chat, ChatId, ProtectionStatus};
 use crate::constants::{Blocked, Chattype};
@@ -16,7 +16,7 @@ use crate::{chat, stock_str};
 
 use super::bobstate::{BobHandshakeStage, BobState};
 use super::qrinvite::QrInvite;
-use super::{HandshakeMessage, JoinError};
+use super::HandshakeMessage;
 
 /// Starts the securejoin protocol with the QR `invite`.
 ///
@@ -30,10 +30,7 @@ use super::{HandshakeMessage, JoinError};
 ///
 /// The [`ChatId`] of the created chat is returned, for a SetupContact QR this is the 1:1
 /// chat with Alice, for a SecureJoin QR this is the group chat.
-pub(super) async fn start_protocol(
-    context: &Context,
-    invite: QrInvite,
-) -> Result<ChatId, JoinError> {
+pub(super) async fn start_protocol(context: &Context, invite: QrInvite) -> Result<ChatId> {
     // A 1:1 chat is needed to send messages to Alice.  When joining a group this chat is
     // hidden, if a user starts sending messages in it it will be unhidden in
     // dc_receive_imf.
@@ -43,7 +40,7 @@ pub(super) async fn start_protocol(
     };
     let chat_id = ChatId::create_for_contact_with_blocked(context, invite.contact_id(), hidden)
         .await
-        .map_err(JoinError::UnknownContact)?;
+        .with_context(|| format!("can't create chat for contact {}", invite.contact_id()))?;
 
     // Now start the protocol and initialise the state
     let (state, stage, aborted_states) =

src/securejoin/bobstate.rs

@@ -22,9 +22,7 @@ use crate::param::Param;
 use crate::sql::Sql;
 
 use super::qrinvite::QrInvite;
-use super::{
-    encrypted_and_signed, fingerprint_equals_sender, mark_peer_as_verified, JoinError, SendMsgError,
-};
+use super::{encrypted_and_signed, fingerprint_equals_sender, mark_peer_as_verified};
 
 /// The stage of the [`BobState`] securejoin handshake protocol state machine.
 ///
@@ -94,7 +92,7 @@ impl BobState {
         context: &Context,
         invite: QrInvite,
         chat_id: ChatId,
-    ) -> Result<(Self, BobHandshakeStage, Vec<Self>), JoinError> {
+    ) -> Result<(Self, BobHandshakeStage, Vec<Self>)> {
         let (stage, next) =
             if fingerprint_equals_sender(context, invite.fingerprint(), invite.contact_id()).await?
             {
@@ -404,11 +402,7 @@ impl BobState {
     /// Sends the requested handshake message to Alice.
     ///
     /// This takes care of adding the required headers for the step.
-    async fn send_handshake_message(
-        &self,
-        context: &Context,
-        step: BobHandshakeMsg,
-    ) -> Result<(), SendMsgError> {
+    async fn send_handshake_message(&self, context: &Context, step: BobHandshakeMsg) -> Result<()> {
         send_handshake_message(context, &self.invite, self.chat_id, step).await
     }
 }
@@ -422,7 +416,7 @@ async fn send_handshake_message(
     invite: &QrInvite,
     chat_id: ChatId,
     step: BobHandshakeMsg,
-) -> Result<(), SendMsgError> {
+) -> Result<()> {
     let mut msg = Message {
         viewtype: Viewtype::Text,
         text: Some(step.body_text(invite)),