From 72242cf152dfedd65e99af05d66ae8abd2fa6532 Mon Sep 17 00:00:00 2001
From: Adi Seredinschi <adi@informal.systems>
Date: Tue, 26 Jan 2021 18:46:31 +0100
Subject: [PATCH] Include cause in Failed errors (#555). Double-checking
 'required' tag.

---
 relayer-cli/src/commands/query/channel.rs |  6 +++---
 relayer-cli/src/commands/query/client.rs  |  4 ++--
 relayer-cli/src/commands/tx/transfer.rs   |  9 +++++----
 relayer-cli/src/conclude.rs               | 12 ++++++++++++
 relayer/src/channel.rs                    |  2 +-
 relayer/src/connection.rs                 |  4 ++--
 6 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/relayer-cli/src/commands/query/channel.rs b/relayer-cli/src/commands/query/channel.rs
index 31db1dfe84..b53b574e03 100644
--- a/relayer-cli/src/commands/query/channel.rs
+++ b/relayer-cli/src/commands/query/channel.rs
@@ -18,13 +18,13 @@ use crate::prelude::*;
 
 #[derive(Clone, Command, Debug, Options)]
 pub struct QueryChannelEndCmd {
-    #[options(free, help = "identifier of the chain to query")]
+    #[options(free, required, help = "identifier of the chain to query")]
     chain_id: Option<ChainId>,
 
-    #[options(free, help = "identifier of the port to query")]
+    #[options(free, required, help = "identifier of the port to query")]
     port_id: Option<String>,
 
-    #[options(free, help = "identifier of the channel to query")]
+    #[options(free, required, help = "identifier of the channel to query")]
     channel_id: Option<String>,
 
     #[options(help = "height of the state to query", short = "h")]
diff --git a/relayer-cli/src/commands/query/client.rs b/relayer-cli/src/commands/query/client.rs
index 168b260bab..151fefcb5c 100644
--- a/relayer-cli/src/commands/query/client.rs
+++ b/relayer-cli/src/commands/query/client.rs
@@ -22,10 +22,10 @@ use crate::prelude::*;
 /// Query client state command
 #[derive(Clone, Command, Debug, Options)]
 pub struct QueryClientStateCmd {
-    #[options(free, help = "identifier of the chain to query")]
+    #[options(free, required, help = "identifier of the chain to query")]
     chain_id: Option<ChainId>,
 
-    #[options(free, help = "identifier of the client to query")]
+    #[options(free, required, help = "identifier of the client to query")]
     client_id: Option<String>,
 
     #[options(help = "the chain height which this query should reflect", short = "h")]
diff --git a/relayer-cli/src/commands/tx/transfer.rs b/relayer-cli/src/commands/tx/transfer.rs
index 1adea1cd0d..1b41224be9 100644
--- a/relayer-cli/src/commands/tx/transfer.rs
+++ b/relayer-cli/src/commands/tx/transfer.rs
@@ -17,20 +17,21 @@ use crate::prelude::*;
 
 #[derive(Clone, Command, Debug, Options)]
 pub struct TxRawSendPacketCmd {
-    #[options(free, help = "identifier of the source chain")]
+    #[options(free, required, help = "identifier of the source chain")]
     src_chain_id: ChainId,
 
-    #[options(free, help = "identifier of the destination chain")]
+    #[options(free, required, help = "identifier of the destination chain")]
     dest_chain_id: ChainId,
 
-    #[options(free, help = "identifier of the source port")]
+    #[options(free, required, help = "identifier of the source port")]
     src_port_id: PortId,
 
-    #[options(free, help = "identifier of the source channel")]
+    #[options(free, required, help = "identifier of the source channel")]
     src_channel_id: ChannelId,
 
     #[options(
         free,
+        required,
         help = "amount of coins (samoleans, by default) to send (e.g. `100000`)"
     )]
     amount: u64,
diff --git a/relayer-cli/src/conclude.rs b/relayer-cli/src/conclude.rs
index 900fa79ddb..3299741f8a 100644
--- a/relayer-cli/src/conclude.rs
+++ b/relayer-cli/src/conclude.rs
@@ -26,6 +26,18 @@
 //! Output::error(format!("{}", e)).exit();
 //! ```
 //!
+//! #### Note:
+//! The resulting output that this approach generates is determined by the 'error' annotation given
+//! to the error object `Kind::Query`. If this error object comprises any positional arguments,
+//! e.g. as achieved by `Query(String, String)`, then it is important to cover these arguments
+//! in the `error` annotation, for instance:
+//! ```compile_fail
+//! #[derive(Debug, Error)]
+//! pub enum Kind {
+//!     #[error("failed with underlying causes: {0}, {1}")]
+//!     Query(String, String),  // ...
+//! ```
+//!
 //! - Exit from a query/tx with success:
 //!
 //! ```compile_fail
diff --git a/relayer/src/channel.rs b/relayer/src/channel.rs
index 793803521a..505c2d135c 100644
--- a/relayer/src/channel.rs
+++ b/relayer/src/channel.rs
@@ -25,7 +25,7 @@ use crate::relay::MAX_ITER;
 
 #[derive(Debug, Error)]
 pub enum ChannelError {
-    #[error("failed")]
+    #[error("failed with underlying cause: {0}")]
     Failed(String),
 
     #[error("failed during an operation on client ({0}) hosted by chain ({1}) with error: {2}")]
diff --git a/relayer/src/connection.rs b/relayer/src/connection.rs
index 74acb2a830..a65ef74b65 100644
--- a/relayer/src/connection.rs
+++ b/relayer/src/connection.rs
@@ -25,10 +25,10 @@ use crate::relay::MAX_ITER;
 
 #[derive(Debug, Error)]
 pub enum ConnectionError {
-    #[error("Failed")]
+    #[error("failed with underlying cause: {0}")]
     Failed(String),
 
-    #[error("constructor parameters do not match")]
+    #[error("constructor parameters do not match: underlying error: {0}")]
     ConstructorFailed(String),
 
     #[error("failed during a query to chain id {0} due to underlying error: {1}")]