Parse cron entries directly into a useful structure on configuration load

Cargo.lock

@@ -389,8 +389,7 @@ checksum = "8aebca1129a03dc6dc2b127edd729435bbc4a37e1d5f4d7513165089ceb02634"
 [[package]]
 name = "cron"
 version = "0.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab00a636277f7ea5d8dd92ac7a5099fc9a46e5327bba84d3640b41ae127eada9"
+source = "git+https://github.com/zslayton/cron?rev=e52fef0#e52fef0d2c2018eaf0f8c84eada3c82e8e6e3651"
 dependencies = [
  "chrono",
  "error-chain 0.10.0",
@@ -1364,6 +1363,7 @@ name = "urci"
 version = "0.1.0"
 dependencies = [
  "async-std",
+ "chrono",
  "cron",
  "serde",
  "serde_derive",

Cargo.toml

@@ -6,7 +6,9 @@ edition = "2018"
 
 [dependencies]
 async-std = { version = "~1.6.0", features = ["attributes"] }
-cron = "~0.6.1"
+chrono = "~0.4.13"
+# This version has Display implemented on cron::Schedule
+cron = { git = "https://github.com/zslayton/cron", rev = "e52fef0" }
 serde = { version = "~1.0.106", features = ["rc"] }
 serde_derive = "~1.0.106"
 serde_json = "~1.0.0"

src/config.rs

@@ -3,6 +3,8 @@
  * configuration file
  */
 
+use serde::de::{Deserialize, Deserializer};
+use std::str::FromStr;
 
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
@@ -21,10 +23,21 @@ pub struct Project {
     scm: Scm,
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Trigger {
-    cron: Option<String>,
+    #[serde(deserialize_with = "deserialize_cron_schedule")]
+    cron: Option<cron::Schedule>,
+}
+
+impl std::fmt::Debug for Trigger {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        write!(formatter, "Trigger: ")?;
+        if let Some(cron) = &self.cron {
+            write!(formatter, "cron: {}", cron)?;
+        }
+        Ok(())
+    }
 }
 
 #[derive(Debug, Deserialize)]
@@ -43,3 +56,32 @@ pub struct Agent {
 #[serde(rename_all = "camelCase")]
 pub struct Handler {
 }
+
+
+fn deserialize_cron_schedule<'de, D>(deserializer: D) -> Result<Option<cron::Schedule>, D::Error>
+where D: Deserializer<'de> {
+    let buf = String::deserialize(deserializer)?;
+
+    if let Ok(schedule) = cron::Schedule::from_str(&buf) {
+        return Ok(Some(schedule));
+    }
+    Err(serde::de::Error::custom("Failed to parse cron, make sure you have at least six fields"))
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_cron_deserialize() {
+        let trigger_yaml = r#"---
+# Fire every second lol
+cron: '* * * * * *'
+
+"#;
+        let trigger: Trigger = serde_yaml::from_str(trigger_yaml)
+            .expect("Should be able to parse our yaml");
+        assert!(trigger.cron.is_some());
+    }
+}