Require input for date format (#7043)

crates/nu-command/src/date/format.rs

@@ -61,6 +61,13 @@ impl Command for SubCommand {
 
         let format = call.opt::<Spanned<String>>(engine_state, stack, 0)?;
 
+        if input.is_nothing() {
+            return Err(ShellError::UnsupportedInput(
+                "Input was nothing. You must pipe an input to this command.".into(),
+                head,
+            ));
+        }
+
         input.map(
             move |value| match &format {
                 Some(format) => format_helper(value, format.item.as_str(), format.span, head),
@@ -147,10 +154,6 @@ fn format_helper(value: Value, formatter: &str, formatter_span: Span, head_span:
                 Err(e) => e,
             }
         }
-        Value::Nothing { .. } => {
-            let dt = Local::now();
-            format_from(dt, formatter, formatter_span)
-        }
         _ => Value::Error {
             error: ShellError::DatetimeParseError(head_span),
         },
@@ -176,13 +179,6 @@ fn format_helper_rfc2822(value: Value, span: Span) -> Value {
                 Err(e) => e,
             }
         }
-        Value::Nothing { span: _ } => {
-            let dt = Local::now();
-            Value::String {
-                val: dt.with_timezone(dt.offset()).to_rfc2822(),
-                span,
-            }
-        }
         _ => Value::Error {
             error: ShellError::DatetimeParseError(span),
         },

crates/nu-command/tests/commands/date/format.rs

@@ -5,7 +5,7 @@ fn formatter_not_valid() {
     let actual = nu!(
         cwd: ".", pipeline(
         r#"
-        date format '%N'
+        date now | date format '%N'
         "#
         )
     );
@@ -13,6 +13,19 @@ fn formatter_not_valid() {
     assert!(actual.err.contains("invalid format"));
 }
 
+#[test]
+fn fails_without_input() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        date format "%c"
+        "#
+        )
+    );
+
+    assert!(actual.err.contains("Unsupported input"));
+}
+
 #[test]
 fn locale_format_respect_different_locale() {
     let actual = nu!(