date: improve range of accepted values for --set

Author: BenWiederhake

src/uu/date/src/date.rs

@@ -74,7 +74,7 @@ struct Settings {
     utc: bool,
     format: Format,
     date_source: DateSource,
-    set_to: Option<DateTime<FixedOffset>>,
+    set_to: Option<String>,
 }
 
 /// Various ways of displaying the date
@@ -185,22 +185,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         DateSource::Now
     };
 
-    let set_to = match matches.get_one::<String>(OPT_SET).map(parse_date) {
-        None => None,
-        Some(Err((input, _err))) => {
-            return Err(USimpleError::new(
-                1,
-                format!("invalid date {}", input.quote()),
-            ));
-        }
-        Some(Ok(date)) => Some(date),
-    };
+    let set_to = matches.get_one::<String>(OPT_SET);
 
     let settings = Settings {
         utc: matches.get_flag(OPT_UNIVERSAL),
         format,
         date_source,
-        set_to,
+        set_to: set_to.cloned(),
     };
 
     // Get the current time, either in the local time zone or UTC.
@@ -213,7 +204,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     };
 
     // Iterate over all dates - whether it's a single date or a file.
-    let dates: Box<dyn Iterator<Item = _>> = if let Some(date) = settings.set_to {
+    let dates: Box<dyn Iterator<Item = _>> = if let Some(date_string) = &settings.set_to {
+        let date = parse_datetime::parse_datetime_at_date(now.into(), date_string)
+            .map_err(|_| USimpleError::new(1, format!("invalid date {}", date_string.quote())))?;
         // All set time functions expect UTC datetimes.
         let date: DateTime<Utc> = if settings.utc {
             date.with_timezone(&Utc)

tests/by-util/test_date.rs

@@ -284,6 +284,27 @@ fn test_date_set_permissions_error() {
     }
 }
 
+#[test]
+#[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
+fn test_date_set_permissions_error_interpreted() {
+    // This implicitly tests that the given strings are interpreted as valid dates,
+    // because parsing errors would have been discovered earlier in the process.
+    if !(geteuid() == 0 || uucore::os::is_wsl_1()) {
+        for date_string in [
+            "yesterday",
+            // TODO "a fortnight ago",
+            "42 days",
+            "2001-02-03",
+            "20010203",
+            // TODO "02/03/2001",
+        ] {
+            let result = new_ucmd!().arg("-s").arg(date_string).fails();
+            // stdout depends on the specific date; don't check it.
+            assert!(result.stderr_str().starts_with("date: cannot set date: "));
+        }
+    }
+}
+
 #[test]
 #[cfg(all(unix, not(any(target_os = "android", target_os = "macos"))))]
 fn test_date_set_permissions_error_repeated() {