feat: Implement timezone offset config option for the time module (#463)

This allows users to configure the time module to display time with a timezone offset other than just their local timezone.

docs/config/README.md

@@ -895,12 +895,22 @@ To enable it, set `disabled` to `false` in your configuration file.
 
 ### Options
 
+<<<<<<< HEAD
+| Variable          | Default       | Description                                                                                                         |
+| ----------------- | ------------- | ------------------------------------------------------------------------------------------------------------------- |
+| `12hr`            | `false`       | Enables 12 hour formatting                                                                                          |
+| `format`          | see below     | The [chrono format string](https://docs.rs/chrono/0.4.7/chrono/format/strftime/index.html) used to format the time. |
+| `style`           | `bold yellow` | The style for the module time                                                                                       |
+| `disabled`        | `true`        | Disables the `time` module.                                                                                         |
+| `utc_time_offset` | `local`       | Sets the UTC offset to use. Range from -24 < x < 24. Allows floats to accomodate 30/45 minute timezone offsets.     |
+=======
 | Variable   | Default       | Description                                                                                                         |
 | ---------- | ------------- | ------------------------------------------------------------------------------------------------------------------- |
 | `use_12hr` | `false`       | Enables 12 hour formatting                                                                                          |
 | `format`   | see below     | The [chrono format string](https://docs.rs/chrono/0.4.7/chrono/format/strftime/index.html) used to format the time. |
 | `style`    | `bold yellow` | The style for the module time                                                                                       |
 | `disabled` | `true`        | Disables the `time` module.                                                                                         |
+>>>>>>> master
 
 If `use_12hr` is `true`, then `format` defaults to `"%r"`. Otherwise, it defaults to `"%T"`.
 Manually setting `format` will override the `use_12hr` setting.

src/configs/time.rs

@@ -9,6 +9,7 @@ pub struct TimeConfig<'a> {
     pub format: Option<&'a str>,
     pub style: Style,
     pub disabled: bool,
+    pub utc_time_offset: &'a str,
 }
 
 impl<'a> RootModuleConfig<'a> for TimeConfig<'a> {
@@ -18,6 +19,7 @@ impl<'a> RootModuleConfig<'a> for TimeConfig<'a> {
             format: None,
             style: Color::Yellow.bold(),
             disabled: true,
+            utc_time_offset: "local",
         }
     }
 }

src/modules/time.rs

@@ -1,4 +1,4 @@
-use chrono::{DateTime, Local};
+use chrono::{DateTime, FixedOffset, Local, Utc};
 
 use super::{Context, Module};
 
@@ -23,8 +23,19 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         time_format
     );
 
-    let local: DateTime<Local> = Local::now();
-    let formatted_time_string = format_time(time_format, local);
+    let formatted_time_string = if config.utc_time_offset != "local" {
+        match create_offset_time_string(Utc::now(), &config.utc_time_offset, &time_format) {
+            Ok(formatted_string) => formatted_string,
+            Err(_) => {
+                log::warn!(
+                    "Invalid utc_time_offset configuration provided! Falling back to \"local\"."
+                );
+                format_time(&time_format, Local::now())
+            }
+        }
+    } else {
+        format_time(&time_format, Local::now())
+    };
 
     module.set_style(config.style);
 
@@ -41,12 +52,41 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     Some(module)
 }
 
+fn create_offset_time_string(
+    utc_time: DateTime<Utc>,
+    utc_time_offset_str: &str,
+    time_format: &str,
+) -> Result<String, &'static str> {
+    // Using floats to allow 30/45 minute offsets: https://www.timeanddate.com/time/time-zones-interesting.html
+    let utc_time_offset_in_hours = match utc_time_offset_str.parse::<f32>() {
+        Ok(parsed_value) => parsed_value,
+        // Passing out of range value to force falling back to "local"
+        Err(_) => 25_f32,
+    };
+    if utc_time_offset_in_hours < 24_f32 && utc_time_offset_in_hours > -24_f32 {
+        let utc_offset_in_seconds: i32 = (utc_time_offset_in_hours * 3600_f32) as i32;
+        let timezone_offset = FixedOffset::east(utc_offset_in_seconds);
+        log::trace!("Target timezone offset is {}", timezone_offset);
+
+        let target_time = utc_time.with_timezone(&timezone_offset);
+        log::trace!("Time in target timezone now is {}", target_time);
+
+        Ok(format_time_fixed_offset(&time_format, target_time))
+    } else {
+        Err("Invalid timezone offset.")
+    }
+}
+
 /// Format a given time into the given string. This function should be referentially
 /// transparent, which makes it easy to test (unlike anything involving the actual time)
 fn format_time(time_format: &str, local_time: DateTime<Local>) -> String {
     local_time.format(time_format).to_string()
 }
 
+fn format_time_fixed_offset(time_format: &str, utc_time: DateTime<FixedOffset>) -> String {
+    utc_time.format(time_format).to_string()
+}
+
 /* Because we cannot make acceptance tests for the time module, these unit
 tests become extra important */
 #[cfg(test)]
@@ -105,4 +145,167 @@ mod tests {
         let formatted = format_time("[%T]", time);
         assert_eq!(formatted, "[15:36:47]");
     }
+
+    #[test]
+    fn test_midnight_12hr_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(0, 0, 0)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset(FMT_12, time);
+        assert_eq!(formatted, "12:00:00 AM");
+    }
+
+    #[test]
+    fn test_midnight_24hr_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(0, 0, 0)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset(FMT_24, time);
+        assert_eq!(formatted, "00:00:00");
+    }
+
+    #[test]
+    fn test_noon_12hr_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(12, 0, 0)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset(FMT_12, time);
+        assert_eq!(formatted, "12:00:00 PM");
+    }
+
+    #[test]
+    fn test_noon_24hr_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(12, 0, 0)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset(FMT_24, time);
+        assert_eq!(formatted, "12:00:00");
+    }
+
+    #[test]
+    fn test_arbtime_12hr_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(15, 36, 47)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset(FMT_12, time);
+        assert_eq!(formatted, "03:36:47 PM");
+    }
+
+    #[test]
+    fn test_arbtime_24hr_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(15, 36, 47)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset(FMT_24, time);
+        assert_eq!(formatted, "15:36:47");
+    }
+
+    #[test]
+    fn test_format_with_paren_fixed_offset() {
+        let timezone_offset = FixedOffset::east(0);
+        let time = Utc
+            .ymd(2014, 7, 8)
+            .and_hms(15, 36, 47)
+            .with_timezone(&timezone_offset);
+        let formatted = format_time_fixed_offset("[%T]", time);
+        assert_eq!(formatted, "[15:36:47]");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_minus_3() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "-3";
+
+        let actual = create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12).unwrap();
+        assert_eq!(actual, "12:36:47 PM");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_plus_5() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "+5";
+
+        let actual = create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12).unwrap();
+        assert_eq!(actual, "08:36:47 PM");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_plus_9_30() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "+9.5";
+
+        let actual = create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12).unwrap();
+        assert_eq!(actual, "01:06:47 AM");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_plus_5_45() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "+5.75";
+
+        let actual = create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12).unwrap();
+        assert_eq!(actual, "09:21:47 PM");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_plus_24() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "+24";
+
+        create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12)
+            .err()
+            .expect("Invalid timezone offset.");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_minus_24() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "-24";
+
+        create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12)
+            .err()
+            .expect("Invalid timezone offset.");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_plus_9001() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "+9001";
+
+        create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12)
+            .err()
+            .expect("Invalid timezone offset.");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_minus_4242() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "-4242";
+
+        create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12)
+            .err()
+            .expect("Invalid timezone offset.");
+    }
+
+    #[test]
+    fn test_create_formatted_time_string_with_invalid_string() {
+        let utc_time: DateTime<Utc> = Utc.ymd(2014, 7, 8).and_hms(15, 36, 47);
+        let utc_time_offset_str = "completely wrong config";
+
+        create_offset_time_string(utc_time, &utc_time_offset_str, FMT_12)
+            .err()
+            .expect("Invalid timezone offset.");
+    }
 }