Improve CantFindColumn and ColumnAlreadyExists errors (#7164)

* Improve CantFindColumn and ColumnAlreadyExists errors

* Update tests

crates/nu-command/src/filters/group_by.rs

@@ -250,6 +250,7 @@ pub fn group(
                     move |_, row: &Value| match row.get_data_by_key(&column_name.item) {
                         Some(group_key) => Ok(group_key.as_string()?),
                         None => Err(ShellError::CantFindColumn(
+                            column_name.item.to_string(),
                             column_name.span,
                             row.span().unwrap_or(column_name.span),
                         )),

crates/nu-command/src/filters/split_by.rs

@@ -137,6 +137,7 @@ pub fn split_by(
             });
             Ok(split(&splitter, input, name)?)
         }
+        // This uses the same format as the 'requires a column name' error in sort_utils.rs
         None => Err(ShellError::GenericError(
             "expected name".into(),
             "requires a column name for splitting".into(),
@@ -165,6 +166,7 @@ pub fn split(
                     move |_, row: &Value| match row.get_data_by_key(&column_name.item) {
                         Some(group_key) => Ok(group_key.as_string()?),
                         None => Err(ShellError::CantFindColumn(
+                            column_name.item.to_string(),
                             column_name.span,
                             row.span().unwrap_or(column_name.span),
                         )),

crates/nu-command/src/sort_utils.rs

@@ -1,5 +1,5 @@
 use alphanumeric_sort::compare_str;
-use nu_engine::column::column_does_not_exist;
+use nu_engine::column::nonexistent_column;
 use nu_protocol::{ShellError, Span, Value};
 use std::cmp::Ordering;
 
@@ -81,12 +81,18 @@ pub fn sort(
             ..
         } => {
             if sort_columns.is_empty() {
-                println!("sort-by requires a column name to sort table data");
-                return Err(ShellError::CantFindColumn(span, span));
+                // This uses the same format as the 'requires a column name' error in split_by.rs
+                return Err(ShellError::GenericError(
+                    "expected name".into(),
+                    "requires a column name to sort table data".into(),
+                    Some(span),
+                    None,
+                    Vec::new(),
+                ));
             }
 
-            if column_does_not_exist(sort_columns.clone(), cols.to_vec()) {
-                return Err(ShellError::CantFindColumn(span, span));
+            if let Some(nonexistent) = nonexistent_column(sort_columns.clone(), cols.to_vec()) {
+                return Err(ShellError::CantFindColumn(nonexistent, span, span));
             }
 
             // check to make sure each value in each column in the record

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

@@ -24,7 +24,9 @@ fn insert_the_column_conflict() {
         "#
     ));
 
-    assert!(actual.err.contains("column already exists"));
+    assert!(actual
+        .err
+        .contains("column 'pretty_assertions' already exists"));
 }
 
 #[test]

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

@@ -95,3 +95,13 @@ fn update_past_end_list() {
 
     assert!(actual.err.contains("too large"));
 }
+
+#[test]
+fn update_nonexistent_column() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{a:1} | update b 2"#
+    ));
+
+    assert!(actual.err.contains("cannot find column 'b'"));
+}