Clean up reading/writing to files

5 files changed, 50 insertions, 25 deletions

diff --git a/src/config.rs b/src/config.rs
index 1d854b9..af51de3 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,10 +1,10 @@
 use directories::ProjectDirs;
 use serde::{Deserialize, Serialize};
 use std::fs;
-use std::fs::File;
 use std::path::PathBuf;
 
-use crate::error::{Error, PermissionType, Result};
+use crate::error::{Error, Result};
+use crate::utils;
 
 #[derive(Deserialize, Serialize, Debug)]
 pub struct Config {
@@ -27,25 +27,22 @@ impl Default for Config {
 pub fn user_config() -> Result<Config> {
     let project = project_dir()?;
     let dir = project.config_dir();
-    fs::create_dir_all(&dir)
-        .map_err(|_| Error::Permissions(PermissionType::Create, dir.to_path_buf()))?;
+    fs::create_dir_all(&dir)?;
     let filename = config_file_name()?;
-    match File::open(&filename) {
-        Err(_) => {
+    match utils::open_file(&filename)? {
+        None => {
             let def = Config::default();
             write_config(&def)?;
             Ok(def)
         }
-        Ok(file) => serde_yaml::from_reader(file).map_err(|_| Error::MalformedFile(filename)),
+        Some(file) => serde_yaml::from_reader(file).map_err(|_| Error::MalformedFile(filename)),
     }
 }
 
 fn write_config(config: &Config) -> Result<()> {
     let filename = config_file_name()?;
-    let file = File::create(&filename)
-        .map_err(|_| Error::Permissions(PermissionType::Create, filename.clone()))?;
-    serde_yaml::to_writer(file, config)
-        .map_err(|_| Error::Permissions(PermissionType::Write, filename.clone()))
+    let file = utils::create_file(&filename)?;
+    Ok(serde_yaml::to_writer(file, config)?)
 }
 
 fn config_file_name() -> Result<PathBuf> {
diff --git a/src/error.rs b/src/error.rs
index d125fb2..86fb55f 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -10,6 +10,10 @@ pub enum Error {
     Crossterm(#[from] crossterm::ErrorKind),
     #[error("Reqwest error: {0}")]
     Reqwest(#[from] reqwest::Error),
+    #[error("SerdeJson error: {0}")]
+    SerdeJson(#[from] serde_json::Error),
+    #[error("SerdeYaml error: {0}")]
+    SerdeYaml(#[from] serde_yaml::Error),
     #[error("IO error: {0}")]
     IO(#[from] std::io::Error),
     #[error("File `{}` is malformed; try removing it", .0.display())]
@@ -28,6 +32,6 @@ pub enum Error {
 
 #[derive(Debug)]
 pub enum PermissionType {
-    Create,
+    Read,
     Write,
 }
diff --git a/src/main.rs b/src/main.rs
index 70ab6f4..7d1dd26 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ mod config;
 mod error;
 mod stackexchange;
 mod term;
+mod utils;
 
 use crossterm::style::Color;
 use error::Error;
diff --git a/src/stackexchange.rs b/src/stackexchange.rs
index dce05de..cf03399 100644
--- a/src/stackexchange.rs
+++ b/src/stackexchange.rs
@@ -4,11 +4,11 @@ use reqwest::Url;
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::fs;
-use std::fs::File;
 use std::path::PathBuf;
 
 use crate::config::{project_dir, Config};
-use crate::error::{Error, PermissionType, Result};
+use crate::error::{Error, Result};
+use crate::utils;
 
 /// StackExchange API v2.2 URL
 const SE_API_URL: &str = "http://api.stackexchange.com";
@@ -131,8 +131,7 @@ impl LocalStorage {
     pub fn new() -> Result<Self> {
         let project = project_dir()?;
         let dir = project.cache_dir();
-        fs::create_dir_all(&dir)
-            .map_err(|_| Error::Permissions(PermissionType::Create, dir.to_path_buf()))?;
+        fs::create_dir_all(&dir)?;
         Ok(LocalStorage {
             sites: None,
             filename: dir.join("sites.json"),
@@ -164,12 +163,14 @@ impl LocalStorage {
     }
 
     fn fetch_local_sites(&mut self) -> Result<bool> {
-        if let Ok(file) = File::open(&self.filename) {
-            self.sites = serde_json::from_reader(file)
-                .map_err(|_| Error::MalformedFile(self.filename.clone()))?;
-            return Ok(true);
+        match utils::open_file(&self.filename)? {
+            Some(file) => {
+                self.sites = serde_json::from_reader(file)
+                    .map_err(|_| Error::MalformedFile(self.filename.clone()))?;
+                Ok(true)
+            }
+            None => Ok(false),
         }
-        Ok(false)
     }
 
     // TODO decide whether or not I should give LocalStorage an api key..
@@ -195,10 +196,8 @@ impl LocalStorage {
     }
 
     fn store_local_sites(&self) -> Result<()> {
-        let file = File::create(&self.filename)
-            .map_err(|_| Error::Permissions(PermissionType::Create, self.filename.clone()))?;
-        serde_json::to_writer(file, &self.sites)
-            .map_err(|_| Error::Permissions(PermissionType::Write, self.filename.clone()))
+        let file = utils::create_file(&self.filename)?;
+        Ok(serde_json::to_writer(file, &self.sites)?)
     }
 }
 
diff --git a/src/utils.rs b/src/utils.rs
new file mode 100644
index 0000000..d1ffed8
--- /dev/null
+++ b/src/utils.rs
@@ -0,0 +1,24 @@
+use crate::error::{Error, PermissionType, Result};
+use std::fs::File;
+use std::io::ErrorKind;
+use std::path::PathBuf;
+
+pub fn open_file(filename: &PathBuf) -> Result<Option<File>> {
+    File::open(filename).map(Some).or_else(|e| match e {
+        e if e.kind() == ErrorKind::NotFound => Ok(None),
+        e if e.kind() == ErrorKind::PermissionDenied => {
+            Err(Error::Permissions(PermissionType::Read, filename.clone()))
+        }
+        e => Err(Error::from(e)),
+    })
+}
+
+pub fn create_file(filename: &PathBuf) -> Result<File> {
+    File::create(filename).map_err(|e| {
+        if e.kind() == ErrorKind::PermissionDenied {
+            Error::Permissions(PermissionType::Write, filename.clone())
+        } else {
+            Error::from(e)
+        }
+    })
+}