From 345c57915ec1770d282a17d8e456c494ec12a8bf Mon Sep 17 00:00:00 2001
From: Daniel Karzel <daniel@comit.network>
Date: Fri, 29 Jan 2021 11:18:47 +1100
Subject: [PATCH] Use nested Result instead of Error enum

---
 swap/src/config.rs | 23 ++++++++++-------------
 swap/src/main.rs   | 14 +++++++-------
 2 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/swap/src/config.rs b/swap/src/config.rs
index 568da021..4eb21ceb 100644
--- a/swap/src/config.rs
+++ b/swap/src/config.rs
@@ -49,27 +49,24 @@ pub struct Monero {
     pub wallet_rpc_url: Url,
 }
 
-#[derive(thiserror::Error, Debug)]
-pub enum Error {
-    #[error("config not initialized")]
-    ConfigNotInitialized,
-    #[error("other error")]
-    Other(#[from] anyhow::Error),
-}
+#[derive(thiserror::Error, Debug, Clone, Copy)]
+#[error("config not initialized")]
+pub struct ConfigNotInitialized {}
 
-pub fn read_config(config_path: PathBuf) -> anyhow::Result<File, Error> {
+pub fn read_config(config_path: PathBuf) -> Result<Result<File, ConfigNotInitialized>> {
     if config_path.exists() {
         info!(
             "Using config file at default path: {}",
             config_path.display()
         );
     } else {
-        return Err(Error::ConfigNotInitialized);
+        return Ok(Err(ConfigNotInitialized {}));
     }
 
-    File::read(&config_path)
-        .with_context(|| format!("failed to read config file {}", config_path.display()))
-        .map_err(Error::Other)
+    let file = File::read(&config_path)
+        .with_context(|| format!("failed to read config file {}", config_path.display()))?;
+
+    Ok(Ok(file))
 }
 
 pub fn initial_setup<F>(config_path: PathBuf, config_file: F) -> Result<()>
@@ -142,7 +139,7 @@ mod tests {
         };
 
         initial_setup(config_path.clone(), || Ok(expected.clone())).unwrap();
-        let actual = read_config(config_path).unwrap();
+        let actual = read_config(config_path).unwrap().unwrap();
 
         assert_eq!(expected, actual);
     }
diff --git a/swap/src/main.rs b/swap/src/main.rs
index ed0ce487..357f84ae 100644
--- a/swap/src/main.rs
+++ b/swap/src/main.rs
@@ -14,9 +14,11 @@
 
 use crate::{
     cli::{Command, Options, Resume},
-    config::read_config,
+    config::{
+        initial_setup, query_user_for_initial_testnet_config, read_config, ConfigNotInitialized,
+    },
 };
-use anyhow::{bail, Context, Result};
+use anyhow::{Context, Result};
 use database::Database;
 use fs::default_config_path;
 use prettytable::{row, Table};
@@ -24,7 +26,6 @@ use protocol::{alice, bob, bob::Builder, SwapAmounts};
 use settings::Settings;
 use std::sync::Arc;
 use structopt::StructOpt;
-use swap::config::{initial_setup, query_user_for_initial_testnet_config};
 use trace::init_tracing;
 use tracing::{info, log::LevelFilter};
 use uuid::Uuid;
@@ -206,13 +207,12 @@ async fn main() -> Result<()> {
 
 fn init_settings() -> Result<Settings> {
     let config_path = default_config_path()?;
-    let config = match read_config(config_path.clone()) {
+    let config = match read_config(config_path.clone())? {
         Ok(config) => config,
-        Err(config::Error::ConfigNotInitialized) => {
+        Err(ConfigNotInitialized {}) => {
             initial_setup(config_path.clone(), query_user_for_initial_testnet_config)?;
-            read_config(config_path)?
+            read_config(config_path)?.expect("after initial setup config can be read")
         }
-        Err(e) => bail!(e),
     };
 
     let settings = Settings::from_config_file_and_defaults(config);