Make weekday optional in RFC2822

time-rs · Feb 23, 2024 · 7a6a800 · 7a6a800
1 parent 4991a89
commit 7a6a800
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Showing 2 changed files with 43 additions and 31 deletions.
diff --git a/tests/parsing.rs b/tests/parsing.rs
@@ -114,32 +114,31 @@ fn rfc_2822() -> time::Result<()> {
     Ok(())
 }
 
+#[test]
+fn issue_661() -> time::Result<()> {
+    assert_eq!(
+        OffsetDateTime::parse("02 Jan 2021 03:04:05 +0607", &Rfc2822)?,
+        datetime!(2021-01-02 03:04:05 +06:07),
+    );
+    assert_eq!(
+        Date::parse("02 Jan 2021 03:04:05 +0607", &Rfc2822)?,
+        date!(2021 - 01 - 02)
+    );
+
+    Ok(())
+}
+
 #[allow(clippy::cognitive_complexity)] // all test the same thing
 #[test]
 fn rfc_2822_err() {
     // In the first test, the "weekday" component is invalid, we're actually testing the whitespace
     // parser. The error is because the parser attempts and fails to parse the whitespace, but it's
     // optional so it backtracks and attempts to parse the weekday (while still having leading
-    // whitespace), thus failing.
+    // whitespace). The weekday is also optional, so it backtracks and attempts to parse the day.
+    // This component is required, so it fails at this point.
     assert!(matches!(
         OffsetDateTime::parse(" \r\nM", &Rfc2822),
-        invalid_component!("weekday")
-    ));
-    assert!(matches!(
-        OffsetDateTime::parse("Mon,(\u{0}", &Rfc2822),
-        invalid_literal!()
-    ));
-    assert!(matches!(
-        OffsetDateTime::parse("Mon,(", &Rfc2822),
-        invalid_literal!()
-    ));
-    assert!(matches!(
-        OffsetDateTime::parse("Mon,(\\\u{ff}", &Rfc2822),
-        invalid_literal!()
-    ));
-    assert!(matches!(
-        OffsetDateTime::parse("Mon,((\\\u{0})(\\\u{b} )(\\\u{d})", &Rfc2822),
-        invalid_literal!()
+        invalid_component!("day")
     ));
 
     assert!(matches!(

diff --git a/time/src/parsing/parsable.rs b/time/src/parsing/parsable.rs
@@ -165,8 +165,8 @@ impl sealed::Sealed for Rfc2822 {
         let colon = ascii_char::<b':'>;
         let comma = ascii_char::<b','>;
 
-        let input = opt(fws)(input).into_inner();
-        let input = first_match(
+        let input = opt(cfws)(input).into_inner();
+        let weekday = first_match(
             [
                 (b"Mon".as_slice(), Weekday::Monday),
                 (b"Tue".as_slice(), Weekday::Tuesday),
@@ -177,11 +177,16 @@ impl sealed::Sealed for Rfc2822 {
                 (b"Sun".as_slice(), Weekday::Sunday),
             ],
             false,
-        )(input)
-        .and_then(|item| item.consume_value(|value| parsed.set_weekday(value)))
-        .ok_or(InvalidComponent("weekday"))?;
-        let input = comma(input).ok_or(InvalidLiteral)?.into_inner();
-        let input = cfws(input).ok_or(InvalidLiteral)?.into_inner();
+        )(input);
+        let input = if let Some(item) = weekday {
+            let input = item
+                .consume_value(|value| parsed.set_weekday(value))
+                .ok_or(InvalidComponent("weekday"))?;
+            let input = comma(input).ok_or(InvalidLiteral)?.into_inner();
+            opt(cfws)(input).into_inner()
+        } else {
+            input
+        };
         let input = n_to_m_digits::<1, 2, _>(input)
             .and_then(|item| item.consume_value(|value| parsed.set_day(value)))
             .ok_or(InvalidComponent("day"))?;
@@ -307,6 +312,8 @@ impl sealed::Sealed for Rfc2822 {
             })
             .ok_or(InvalidComponent("offset minute"))?;
 
+        let input = opt(cfws)(input).into_inner();
+
         Ok(input)
     }
 
@@ -320,10 +327,10 @@ impl sealed::Sealed for Rfc2822 {
         let colon = ascii_char::<b':'>;
         let comma = ascii_char::<b','>;
 
-        let input = opt(fws)(input).into_inner();
+        let input = opt(cfws)(input).into_inner();
         // This parses the weekday, but we don't actually use the value anywhere. Because of this,
         // just return `()` to avoid unnecessary generated code.
-        let ParsedItem(input, ()) = first_match(
+        let weekday = first_match(
             [
                 (b"Mon".as_slice(), ()),
                 (b"Tue".as_slice(), ()),
@@ -334,10 +341,14 @@ impl sealed::Sealed for Rfc2822 {
                 (b"Sun".as_slice(), ()),
             ],
             false,
-        )(input)
-        .ok_or(InvalidComponent("weekday"))?;
-        let input = comma(input).ok_or(InvalidLiteral)?.into_inner();
-        let input = cfws(input).ok_or(InvalidLiteral)?.into_inner();
+        )(input);
+        let input = if let Some(item) = weekday {
+            let input = item.into_inner();
+            let input = comma(input).ok_or(InvalidLiteral)?.into_inner();
+            opt(cfws)(input).into_inner()
+        } else {
+            input
+        };
         let ParsedItem(input, day) =
             n_to_m_digits::<1, 2, _>(input).ok_or(InvalidComponent("day"))?;
         let input = cfws(input).ok_or(InvalidLiteral)?.into_inner();
@@ -442,6 +453,8 @@ impl sealed::Sealed for Rfc2822 {
             (input, offset_hour, offset_minute.cast_signed())
         };
 
+        let input = opt(cfws)(input).into_inner();
+
         if !input.is_empty() {
             return Err(error::Parse::ParseFromDescription(
                 error::ParseFromDescription::UnexpectedTrailingCharacters,