From 2784e8d2ff19c0bb2291be1c683db43e5693a11f Mon Sep 17 00:00:00 2001
From: CodeSteak <codesteak@shellf.art>
Date: Tue, 7 May 2019 18:44:59 +0200
Subject: [PATCH] implement date parsing as FromStr trait

---
 server/texture-sync-server/src/model/date.rs  | 61 ++++++++++++++-----
 .../src/persistency/search/query_filter.rs    |  4 +-
 2 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/server/texture-sync-server/src/model/date.rs b/server/texture-sync-server/src/model/date.rs
index 12e4b94..a4f969d 100644
--- a/server/texture-sync-server/src/model/date.rs
+++ b/server/texture-sync-server/src/model/date.rs
@@ -1,6 +1,7 @@
 use serde::de::Error;
 use serde::Serialize;
 use serde::{Deserialize, Deserializer, Serializer};
+use std::str::FromStr;
 
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Date {
@@ -14,23 +15,49 @@ impl Date {
     pub fn new(year: u16, month: u8, day: u8) -> Self {
         Date { year, month, day }
     }
+}
 
-    pub fn from_str(input: &str) -> Option<Self> {
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum DateParseError {
+    InvalidNumber,
+    MonthOutOfRange,
+    DayOutOfRange,
+    WrongFormat,
+}
+
+impl FromStr for Date {
+    type Err = DateParseError;
+
+    fn from_str(input: &str) -> Result<Date, DateParseError> {
         let mut parts = input.splitn(3, "-");
 
-        let year = parts.next()?.parse::<u16>().ok()?;
-        let month = parts.next()?.parse::<u8>().ok()?;
-        let day = parts.next()?.parse::<u8>().ok()?;
+        let year = parts
+            .next()
+            .ok_or(DateParseError::WrongFormat)?
+            .parse::<u16>()
+            .map_err(|_| DateParseError::InvalidNumber)?;
+
+        let month = parts
+            .next()
+            .ok_or(DateParseError::WrongFormat)?
+            .parse::<u8>()
+            .map_err(|_| DateParseError::InvalidNumber)?;
+
+        let day = parts
+            .next()
+            .ok_or(DateParseError::WrongFormat)?
+            .parse::<u8>()
+            .map_err(|_| DateParseError::InvalidNumber)?;
 
         if month > 12 {
-            return None;
+            return Err(DateParseError::DayOutOfRange);
         }
 
         if day > 31 {
-            return None;
+            return Err(DateParseError::MonthOutOfRange);
         }
 
-        Some(Date { year, month, day })
+        Ok(Date { year, month, day })
     }
 }
 
@@ -54,8 +81,8 @@ impl<'de> Deserialize<'de> for Date {
         let data = String::deserialize(deserializer)?;
 
         match Date::from_str(&data) {
-            Some(date) => Ok(date),
-            None => Err(D::Error::custom(
+            Ok(date) => Ok(date),
+            Err(_) => Err(D::Error::custom(
                 "Expected a String in this format: YYYY-MM-DD.",
             )),
         }
@@ -76,14 +103,20 @@ mod test {
 
     #[test]
     fn from_str() {
-        assert_eq!(Some(Date::new(2019, 10, 10)), Date::from_str("2019-10-10"));
-        assert_eq!(Some(Date::new(2019, 1, 1)), Date::from_str("2019-1-1"));
-        assert_eq!(None, Date::from_str("2019-1-1-444"));
+        assert_eq!(Ok(Date::new(2019, 10, 10)), Date::from_str("2019-10-10"));
+
+        assert_eq!(Ok(Date::new(2019, 1, 1)), Date::from_str("2019-1-1"));
+
+        assert!(Date::from_str("2019-1-1-444").is_err());
+
         assert_eq!(
-            Some(Date::new(2019, 1, 1)),
+            Ok(Date::new(2019, 1, 1)),
             Date::from_str("2019-0000000000001-00000001")
         );
-        assert_eq!(None, Date::from_str("400-400-400"));
+
+        assert!(Date::from_str("XXX-400-400").is_err());
+
+        assert!(Date::from_str("400-400-400").is_err());
     }
 
 }
diff --git a/server/texture-sync-server/src/persistency/search/query_filter.rs b/server/texture-sync-server/src/persistency/search/query_filter.rs
index 0a43db6..fae15e4 100644
--- a/server/texture-sync-server/src/persistency/search/query_filter.rs
+++ b/server/texture-sync-server/src/persistency/search/query_filter.rs
@@ -114,13 +114,13 @@ impl FromStr for QueryFilter {
                 }
                 "a" | "after" => {
                     let date = Date::from_str(filter_arg)
-                        .ok_or(QueryFilterSyntaxError::DateArgumentInvalid)?;
+                        .map_err(|_| QueryFilterSyntaxError::DateArgumentInvalid)?;
 
                     Ok(QueryFilter::SpecialAfterDate(date))
                 }
                 "b" | "bef" | "before" => {
                     let date = Date::from_str(filter_arg)
-                        .ok_or(QueryFilterSyntaxError::DateArgumentInvalid)?;
+                        .map_err(|_| QueryFilterSyntaxError::DateArgumentInvalid)?;
 
                     Ok(QueryFilter::SpecialBeforeDate(date))
                 }