Make to text line endings consistent for list (streams) (#14166)

# Description
Fixes #14151 where `to text` treats list streams and lists values
differently.

# User-Facing Changes
New line is always added after items in a list or record except for the
last item if the `--no-newline` flag is provided.

crates/nu-command/tests/commands/to_text.rs

@@ -1,19 +1,54 @@
 use nu_test_support::nu;
 
-#[test]
-fn list_to_text() {
-    let actual = nu!(r#"["foo" "bar" "baz"] | to text"#);
+const LINE_LEN: usize = if cfg!(target_os = "windows") { 2 } else { 1 };
 
-    // these actually have newlines between them in the real world but nu! strips newlines, grr
-    assert_eq!(actual.out, "foobarbaz");
+#[test]
+fn list() {
+    // Using `str length` since nu! strips newlines, grr
+    let actual = nu!(r#"[] | to text | str length"#);
+    assert_eq!(actual.out, "0");
+
+    let actual = nu!(r#"[a] | to text | str length"#);
+    assert_eq!(actual.out, (1 + LINE_LEN).to_string());
+
+    let actual = nu!(r#"[a b] | to text | str length"#);
+    assert_eq!(actual.out, (2 * (1 + LINE_LEN)).to_string());
 }
 
-// the output should be the same when `to text` gets a ListStream instead of a Value::List
+// The output should be the same when `to text` gets a ListStream instead of a Value::List.
 #[test]
-fn list_stream_to_text() {
-    // use `each` to convert the list to a ListStream
-    let actual = nu!(r#"["foo" "bar" "baz"] | each {|i| $i} | to text"#);
+fn list_stream() {
+    let actual = nu!(r#"[] | each {} | to text | str length"#);
+    assert_eq!(actual.out, "0");
 
-    // these actually have newlines between them in the real world but nu! strips newlines, grr
-    assert_eq!(actual.out, "foobarbaz");
+    let actual = nu!(r#"[a] | each {} | to text | str length"#);
+    assert_eq!(actual.out, (1 + LINE_LEN).to_string());
+
+    let actual = nu!(r#"[a b] | each {} | to text | str length"#);
+    assert_eq!(actual.out, (2 * (1 + LINE_LEN)).to_string());
+}
+
+#[test]
+fn list_no_newline() {
+    let actual = nu!(r#"[] | to text -n | str length"#);
+    assert_eq!(actual.out, "0");
+
+    let actual = nu!(r#"[a] | to text -n | str length"#);
+    assert_eq!(actual.out, "1");
+
+    let actual = nu!(r#"[a b] | to text -n | str length"#);
+    assert_eq!(actual.out, (2 + LINE_LEN).to_string());
+}
+
+// The output should be the same when `to text` gets a ListStream instead of a Value::List.
+#[test]
+fn list_stream_no_newline() {
+    let actual = nu!(r#"[] | each {} | to text -n | str length"#);
+    assert_eq!(actual.out, "0");
+
+    let actual = nu!(r#"[a] | each {} | to text -n | str length"#);
+    assert_eq!(actual.out, "1");
+
+    let actual = nu!(r#"[a b] | each {} | to text -n | str length"#);
+    assert_eq!(actual.out, (2 + LINE_LEN).to_string());
 }