'first' gets first row if no amount desired given.

src/commands/first.rs

@@ -7,7 +7,7 @@ pub struct First;
 
 #[derive(Deserialize)]
 pub struct FirstArgs {
-    amount: Tagged<u64>,
+    rows: Option<Tagged<u64>>,
 }
 
 impl WholeStreamCommand for First {
@@ -16,7 +16,7 @@ impl WholeStreamCommand for First {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("first").required("amount", SyntaxShape::Int)
+        Signature::build("first").optional("rows", SyntaxShape::Int)
     }
 
     fn usage(&self) -> &str {
@@ -33,8 +33,15 @@ impl WholeStreamCommand for First {
 }
 
 fn first(
-    FirstArgs { amount }: FirstArgs,
+    FirstArgs { rows }: FirstArgs,
     context: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
-    Ok(OutputStream::from_input(context.input.values.take(*amount)))
+
+    let rows_desired = if let Some(quantity) = rows {
+        *quantity
+    } else {
+        1
+    };
+
+    Ok(OutputStream::from_input(context.input.values.take(rows_desired)))
 }

tests/commands_test.rs

@@ -32,13 +32,23 @@ fn first_gets_first_rows_by_amount() {
 }
 
 #[test]
-fn first_requires_an_amount() {
-    Playground::setup("first_test_2", |dirs, _| {
-        let actual = nu_error!(
-            cwd: dirs.test(), "ls | first"
-        );
+fn first_gets_first_row_when_no_amount_given() {
+    Playground::setup("first_test_2", |dirs, sandbox| {
+        sandbox.with_files(vec![EmptyFile("los-tres-amigos.PASSTEST.txt")]);
 
-        assert!(actual.contains("requires amount parameter"));
+        let actual = nu!(
+            cwd: dirs.test(), h::pipeline(
+            r#"
+                ls
+                | get name
+                | first
+                | split-column "."
+                | get Column2
+                | echo $it
+            "#
+        ));
+
+        assert_eq!(actual, "PASSTEST");
     })
 }