Err message for sort-by invalid types now shows the mismatched types (#2366)

* make sort-by fail gracefully if mismatched types are compared

* Added a test to check if sorted-by with invalid types exists gracefully

* Linter changes

* removed redundant pattern matching

* Changed the error message

* Added a comma after every argument

* Changed the test to accomodate the new err messages

* Err message for sort-by invalid types now shows the mismatched types

* Lints problems

* Changed unwrap to expect

Cargo.lock

@@ -1,5 +1,15 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "Inflector"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe438c63458706e03479442743baae6c88256498e6431708f6dfc520a26515d3"
+dependencies = [
+ "lazy_static 1.4.0",
+ "regex 1.3.9",
+]
+
 [[package]]
 name = "addr2line"
 version = "0.13.0"
@@ -2956,6 +2966,7 @@ dependencies = [
 name = "nu-cli"
 version = "0.18.2"
 dependencies = [
+ "Inflector",
  "ansi_term 0.12.1",
  "app_dirs2",
  "async-recursion",

crates/nu-cli/src/commands/sort_by.rs

@@ -135,13 +135,20 @@ pub fn sort(
         } => {
             let should_sort_case_insensitively = insensitive && vec.iter().all(|x| x.is_string());
 
-            if !vec
+            if let Some(values) = vec
                 .windows(2)
-                .all(|elem| coerce_compare(&elem[0], &elem[1]).is_ok())
+                .map(|elem| coerce_compare(&elem[0], &elem[1]))
+                .find(|elem| elem.is_err())
             {
+                let (type_1, type_2) = values
+                    .err()
+                    .expect("An error ocourred in the checking of types");
                 return Err(ShellError::labeled_error(
                     "Not all values can be compared",
-                    "not all values compare",
+                    format!(
+                        "Unable to sort values, as \"{}\" cannot compare against \"{}\"",
+                        type_1, type_2
+                    ),
                     tag,
                 ));
             }

crates/nu-cli/tests/commands/sort_by.rs

@@ -57,7 +57,9 @@ fn by_invalid_types() {
     ));
 
     assert!(actual.err.contains("Not all values can be compared"));
-    assert!(actual.err.contains("not all values compare"));
+    assert!(actual
+        .err
+        .contains("Unable to sort values, as \"integer\" cannot compare against \"string\""));
 }
 
 #[test]