implement some proper error handling

* implement error handling for Coordinates struct

* complete rough error handling for config

* update reasdme and bump version

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "heliocron"
-version = "0.2.2"
+version = "0.3.0"
 authors = ["Michael Freeborn <michaelfreeborn1@gmail.com>"]
 description = """
 Heliocron is a command line application written in Rust capable of delaying execution of other 
@@ -28,7 +28,6 @@ toml = "0.5"
 [dev-dependencies]
 assert_cmd = "0.12"
 criterion = "0.3"
-guerrilla = "0.1"
 predicates = "1"
 
 [profile.release]

README.md

@@ -13,7 +13,7 @@ $ cargo install heliocron
 .
 .
 $ heliocron --version
-heliocron 0.1.3
+heliocron 0.3.0
 ```
 
 #### 3. Build from source
@@ -22,7 +22,7 @@ $ git clone https://github.com/mfreeborn/heliocron
 $ cd heliocron
 $ cargo build --release
 $ ./target/release/heliocron --version
-heliocron 0.1.3
+heliocron 0.3.0
 ```
 
 ## Usage Examples
@@ -45,8 +45,8 @@ Ever wondered what time sunrise is in Edinburgh on 7th May 2065?
 $ heliocron -d "7 May 2065" -f "%e %B %Y" -l 55.9533N -o 3.1883W report
 LOCATION
 --------
-Latitude:  55.9533
-Longitude: -3.1883
+Latitude:  55.9533N
+Longitude: 3.1883W
 
 DATE
 ----
@@ -72,8 +72,8 @@ Now, using Heliocron without providing specific coordinates will yield the follo
 $ heliocron -d 2020-03-08 report
 LOCATION
 --------
-Latitude:  51.5014
-Longitude: -0.1419
+Latitude:  51.5014N
+Longitude: 0.1419W
 
 DATE
 ----
@@ -92,8 +92,8 @@ Arguments passed in via the command line will override those set in the configur
 $ heliocron -d 2020-03-08 -l 51.4839N -o 0.6044W report
 LOCATION
 --------
-Latitude:  51.4839
-Longitude: -0.6044
+Latitude:  51.4839N
+Longitude: 0.6044W
 
 DATE
 ----

benches/benches.rs

@@ -11,8 +11,8 @@ fn criterion_benchmark(c: &mut Criterion) {
     let date = FixedOffset::east(0).ymd(2020, 2, 25).and_hms(12, 0, 0);
 
     let coordinates = structs::Coordinates {
-        latitude: 51.0,
-        longitude: 4.0,
+        latitude: structs::Latitude { value: 51.0 },
+        longitude: structs::Longitude { value: 4.0 },
     };
 
     c.bench_function("run_report", |b| b.iter(|| run_report(date, coordinates)));

src/bin/heliocron.rs

@@ -2,7 +2,7 @@ use std::process;
 
 use chrono::{Duration, FixedOffset, Local, TimeZone};
 
-use heliocron::{config, enums, report, utils};
+use heliocron::{config, enums, errors, report, utils};
 
 fn wait(offset: Duration, report: report::SolarReport, event: enums::Event) {
     let event_time = match event {
@@ -20,18 +20,26 @@ fn wait(offset: Duration, report: report::SolarReport, event: enums::Event) {
     utils::sleep(duration_to_sleep, sleep_until);
 }
 
-fn main() {
-    let config = config::get_config();
+fn run_heliocron() -> Result<(), errors::HeliocronError> {
+    let config = config::get_config()?;
 
     let report = report::SolarReport::new(config.date, config.coordinates);
 
     match config.subcommand {
         Some(config::Subcommand::Report {}) => println!("{}", report),
-        Some(config::Subcommand::Wait { offset, event }) => wait(offset, report, event),
+        Some(config::Subcommand::Wait { offset, event }) => wait(offset?, report, event?),
         // will never match None as this is caught earlier by StructOpt
-        None => {
-            println!("No subcommand provided!");
-            process::exit(1)
-        }
+        None => println!("No subcommand provided!"),
     }
+    Ok(())
+}
+
+fn main() {
+    process::exit(match run_heliocron() {
+        Ok(_) => 0,
+        Err(err) => {
+            eprintln!("{}", err);
+            1
+        }
+    });
 }

src/config.rs

@@ -5,9 +5,14 @@ use dirs;
 use serde::Deserialize;
 use structopt::clap::AppSettings;
 use structopt::StructOpt;
-use toml;
 
-use super::{enums, parsers, structs};
+use super::{
+    enums,
+    errors::{ConfigErrorKind, HeliocronError},
+    parsers, structs,
+};
+
+type Result<T> = std::result::Result<T, HeliocronError>;
 
 #[derive(Debug, StructOpt)]
 #[structopt(
@@ -50,7 +55,7 @@ pub enum Subcommand {
             default_value = "00:00:00",
             parse(from_str=parsers::parse_offset),
         )]
-        offset: Duration,
+        offset: Result<Duration>,
 
         #[structopt(
             help = "Choose one of {sunrise | sunset} from which to base your delay.", 
@@ -59,7 +64,7 @@ pub enum Subcommand {
             parse(from_str=parsers::parse_event),
             possible_values = &["sunrise", "sunset"]
         )]
-        event: enums::Event,
+        event: Result<enums::Event>,
     },
 }
 
@@ -89,7 +94,7 @@ impl TomlConfig {
         }
     }
 
-    fn from_toml(config: Result<TomlConfig, toml::de::Error>) -> TomlConfig {
+    fn from_toml(config: std::result::Result<TomlConfig, toml::de::Error>) -> TomlConfig {
         match config {
             Ok(conf) => conf,
             _ => TomlConfig::new(),
@@ -106,67 +111,71 @@ pub struct Config {
 }
 
 impl Config {
-    fn merge_toml(mut self, toml_config: TomlConfig) -> Self {
+    fn merge_toml(mut self, toml_config: TomlConfig) -> Result<Config> {
         if let (Some(latitude), Some(longitude)) = (toml_config.latitude, toml_config.longitude) {
-            self.coordinates = structs::Coordinates::from_decimal_degrees(&latitude, &longitude)
+            self.coordinates = structs::Coordinates::from_decimal_degrees(&latitude, &longitude)?
         }
-        self
+        Ok(self)
     }
 
-    fn merge_cli_args(mut self, cli_args: Cli) -> Self {
+    fn merge_cli_args(mut self, cli_args: Cli) -> Result<Config> {
         // merge in location if set. Structopt requires either both or neither of lat and long to be set
         if let (Some(latitude), Some(longitude)) = (cli_args.latitude, cli_args.longitude) {
-            self.coordinates = structs::Coordinates::from_decimal_degrees(&latitude, &longitude)
+            self.coordinates = structs::Coordinates::from_decimal_degrees(&latitude, &longitude)?
         }
 
         // set the date
         let date_args = cli_args.date_args;
         if let Some(date) = date_args.date {
             self.date = parsers::parse_date(
-                Some(&date),
+                &date,
                 &date_args.date_format,
                 date_args.time_zone.as_deref(),
-            );
+            )?;
         }
 
         // set the subcommand to execute
         self.subcommand = Some(cli_args.subcommand);
 
-        self
+        Ok(self)
     }
 }
 
-pub fn get_config() -> Config {
+pub fn get_config() -> Result<Config> {
     // master function for collecting all config variables and returning a single runtime configuration
 
     // 0. Set up default config
     let default_config = Config {
-        coordinates: structs::Coordinates::from_decimal_degrees("51.4769N", "0.0005W"),
+        coordinates: structs::Coordinates::from_decimal_degrees("51.4769N", "0.0005W")?,
         date: Local::today()
             .and_hms(12, 0, 0)
             .with_timezone(&FixedOffset::from_offset(Local::today().offset())),
         subcommand: None,
         event: None,
     };
 
-    // 1. Overwrite defaults with config from ~/.config/heliocron.toml
+    // 1. Overwrite defaults with config from ~/.config/heliocron.toml if present
 
     let path = dirs::config_dir()
-        .unwrap()
+        .unwrap() // this shouldn't ever really be None?
         .join(Path::new("heliocron.toml"));
 
     let file = fs::read_to_string(path);
 
     let config: Config = match file {
-        Ok(f) => default_config.merge_toml(TomlConfig::from_toml(toml::from_str(&f))),
-        // any problems with the config file and we just continue on with the default configuration
-        _ => default_config,
-    };
-
-    // 2. Add/overwrite any currently set config from CLI arguments
+        Ok(f) => match default_config.merge_toml(TomlConfig::from_toml(toml::from_str(&f))) {
+            Ok(merged_config) => Ok(merged_config),
+            // any errors parsing the .toml raise an error
+            Err(_) => Err(HeliocronError::Config(ConfigErrorKind::InvalidTomlFile)),
+        },
+        // any problems opening the .toml file and we just continue on with the default configuration
+        Err(_) => Ok(default_config),
+    }?;
+
+    // 2. Overwrite any currently set config with CLI arguments
     let cli_args = Cli::from_args();
 
-    let config = config.merge_cli_args(cli_args);
+    let config = config.merge_cli_args(cli_args)?;
 
-    config
+    Ok(config)
 }

src/enums.rs

@@ -1,21 +1,22 @@
-use std::str::FromStr;
+use std::result;
+
+use super::errors::{ConfigErrorKind, HeliocronError};
+
+type Result<T> = result::Result<T, HeliocronError>;
 
 #[derive(Debug, PartialEq)]
 pub enum Event {
     Sunrise,
     Sunset,
 }
 
-impl FromStr for Event {
-    type Err = ();
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let s: &str = &s.trim().to_lowercase();
-
-        match s {
-            "sunrise" => Ok(Self::Sunrise),
-            "sunset" => Ok(Self::Sunset),
-            _ => Err(()),
+impl Event {
+    pub fn new(event: &str) -> Result<Event> {
+        let event = event.trim().to_lowercase();
+        match event.as_str() {
+            "sunrise" => Ok(Event::Sunrise),
+            "sunset" => Ok(Event::Sunset),
+            _ => Err(HeliocronError::Config(ConfigErrorKind::InvalidEvent)),
         }
     }
 }

src/errors.rs

@@ -0,0 +1,67 @@
+use std::error;
+
+use chrono;
+
+#[derive(Debug)]
+pub enum HeliocronError {
+    Config(ConfigErrorKind),
+}
+
+#[derive(Debug)]
+pub enum ConfigErrorKind {
+    InvalidCoordindates(&'static str),
+    InvalidTomlFile,
+    ParseDate,
+    InvalidEvent,
+}
+
+impl ConfigErrorKind {
+    fn as_str(&self) -> &str {
+        match *self {
+            ConfigErrorKind::InvalidCoordindates(msg) => msg,
+            ConfigErrorKind::InvalidTomlFile => {
+                "Error parsing .toml file. Ensure that it is of the correct format."
+            }
+            ConfigErrorKind::ParseDate => {
+                "Error parsing date. Ensure the date and timezone formats are correct."
+            }
+            ConfigErrorKind::InvalidEvent => {
+                "Error parsing event. Expected one of {'sunrise' | 'sunset'}"
+            }
+        }
+    }
+}
+
+impl std::fmt::Display for HeliocronError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match *self {
+            HeliocronError::Config(ref err) => write!(
+                f,
+                "Config error: {}",
+                match err {
+                    ConfigErrorKind::InvalidCoordindates(msg) =>
+                        format!("Invalid coordinates - {}", msg),
+                    ConfigErrorKind::InvalidTomlFile => err.as_str().to_string(),
+                    ConfigErrorKind::ParseDate => err.as_str().to_string(),
+                    ConfigErrorKind::InvalidEvent => err.as_str().to_string(),
+                }
+            ),
+        }
+    }
+}
+
+impl error::Error for HeliocronError {
+    fn description(&self) -> &str {
+        match *self {
+            HeliocronError::Config(ref err) => err.as_str(),
+        }
+    }
+}
+
+impl From<chrono::ParseError> for HeliocronError {
+    fn from(err: chrono::ParseError) -> Self {
+        match err {
+            _err => HeliocronError::Config(ConfigErrorKind::ParseDate),
+        }
+    }
+}

src/lib.rs

@@ -1,5 +1,6 @@
 pub mod config;
 pub mod enums;
+pub mod errors;
 pub mod parsers;
 pub mod report;
 pub mod structs;