TRY-44 Fancy error handling (#5)

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+anyhow = "1.0.75"
 cargo-husky = "1.5.0"
 chrono = { version = "0.4.31", default-features = false, features = [
     "clock",

README.md

@@ -5,7 +5,39 @@
 
 This is the main repository for the raytracing project.
 
-## `log` crate
+## `log`
+
+https://crates.io/crates/log
 
 > Usage:  
 > The basic use of the log crate is through the five logging macros: `error!`, `warn!`, `info!`, `debug!` and `trace!` where `error!` represents the highest-priority log messages and trace! the lowest. The log messages are filtered by configuring the log level to exclude messages with a lower priority. Each of these macros accept format strings similarly to println!.
+
+## `anyhow`
+
+https://crates.io/crates/anyhow
+
+> Usage:  
+> This library provides anyhow::Error, a trait object based error type for easy idiomatic error handling in Rust applications.
+
+Example: 
+```rust
+use anyhow::Context;
+
+fn test() -> anyhow::Result<()> {
+    // watch out for the question mark operator
+
+    let file = std::fs::File::create("test.txt").context("Failed to create test file")?;
+
+    file.set_len(1234).context("Failed to set file length")?;
+
+    Ok(())
+}
+```
+
+If this fails the result is a fancy error message:
+```
+Error: Failed to create test file
+
+Caused by:
+    File exists (os error 17)
+```

src/main.rs

@@ -1,5 +1,6 @@
 use std::borrow::Cow;
 
+use anyhow::Context;
 use glium::{
     glutin::{
         dpi::PhysicalSize,
@@ -20,12 +21,8 @@ mod scene;
 
 pub type Color = Vector3<f32>;
 
-pub fn main() {
-    std::fs::create_dir_all("logs").expect("Failed to create logs directory");
-    let log_file_name = format!(
-        "logs/trayracer_{}.log",
-        chrono::Local::now().format("%Y-%m-%d_%H-%M-%S")
-    );
+pub fn main() -> anyhow::Result<()> {
+    std::fs::create_dir_all("logs").context("Failed to create logs directory")?;
 
     let log_level = if cfg!(debug_assertions) {
         LevelFilter::Trace
@@ -42,10 +39,14 @@ pub fn main() {
         WriteLogger::new(
             log_level,
             Config::default(),
-            File::create(log_file_name).unwrap(),
+            File::create(format!(
+                "logs/trayracer_{}.log",
+                chrono::Local::now().format("%Y-%m-%d_%H-%M-%S")
+            ))
+            .context("Failed to create log file")?,
         ),
     ])
-    .expect("Failed to initialize logger");
+    .context("Failed to initialize logger")?;
 
     let window_builder = WindowBuilder::new()
         .with_title("TrayRacer!")
@@ -54,7 +55,8 @@ pub fn main() {
     let context_builder = ContextBuilder::new();
     let event_loop = EventLoop::new();
 
-    let display = glium::Display::new(window_builder, context_builder, &event_loop).unwrap();
+    let display = glium::Display::new(window_builder, context_builder, &event_loop)
+        .context("Failed to create display")?;
 
     event_loop.run(move |e, _, c| match e {
         Event::WindowEvent {
@@ -86,6 +88,7 @@ pub fn main() {
                 UncompressedFloatFormat::F32F32F32F32,
                 MipmapsOption::NoMipmap,
             )
+            .context("Failed to create texture")
             .unwrap();
 
             let mut frame = display.draw();
@@ -106,7 +109,7 @@ pub fn main() {
                 MagnifySamplerFilter::Linear,
             );
 
-            frame.finish().unwrap();
+            frame.finish().context("Failed to finish frame").unwrap();
         }
         Event::WindowEvent { .. } => {}
         Event::RedrawRequested(_) => {}