Fix #6240

crates/compiler/load/tests/test_reporting.rs

@@ -14426,4 +14426,76 @@ All branches in an `if` must have the same type!
  // ),
  // @r""
  // );
+
+ test_report!(
+ issue_6240_1,
+ indoc!(
+ r"
+ {}.abcde
+ "
+ ),
+ @r###"
+ ── TYPE MISMATCH in /code/proj/Main.roc ────────────────────────────────────────
+ 
+ This record doesn’t have a `abcde` field:
+ 
+ 4│ {}.abcde
+ ^^^^^^^^
+ 
+ In fact, it’s a record with no fields at all!
+ "###
+ );
+
+ test_report!(
+ issue_6240_2,
+ indoc!(
+ r#"
+ ("", "").abcde
+ "#
+ ),
+ @r###"
+ ── TYPE MISMATCH in /code/proj/Main.roc ────────────────────────────────────────
+ 
+ This expression is used in an unexpected way:
+ 
+ 4│ ("", "").abcde
+ ^^^^^^^^^^^^^^
+ 
+ It is a tuple of type:
+ 
+ (
+ Str,
+ Str,
+ )a
+ 
+ But you are trying to use it as:
+ 
+ { abcde : * }b
+ "###
+ );
+
+ test_report!(
+ issue_6240_3,
+ indoc!(
+ r"
+ {}.0
+ "
+ ),
+ @r###"
+ ── TYPE MISMATCH in /code/proj/Main.roc ────────────────────────────────────────
+
+ This expression is used in an unexpected way:
+ 
+ 4│ {}.0
+ ^^^^
+ 
+ It is a record of type:
+ 
+ {}
+ 
+ But you are trying to use it as:
+ 
+ (*)b
+ "###
+ );
 }

crates/compiler/mono/src/ir.rs

@@ -4978,12 +4978,17 @@ pub fn with_hole<'a>(
  }
  }
 
+ let struct_index = match index {
+ Some(index) => index,
+ None => return runtime_error(env, "No such field in record"),
+ };
+
  compile_struct_like_access(
  env,
  procs,
  layout_cache,
  field_layouts,
- index.expect("field not in its own type") as _,
+ struct_index,
  *loc_expr,
  record_var,
  hole,
@@ -5076,12 +5081,17 @@ pub fn with_hole<'a>(
  }
  }
 
+ let tuple_index = match final_index {
+ Some(index) => index as u64,
+ None => return runtime_error(env, "No such index in tuple"),
+ };
+
  compile_struct_like_access(
  env,
  procs,
  layout_cache,
  field_layouts,
- final_index.expect("elem not in its own type") as u64,
+ tuple_index,
  *loc_expr,
  tuple_var,
  hole,
@@ -8055,7 +8065,10 @@ fn can_reuse_symbol<'a>(
  .enumerate()
  .find_map(|(current, (label, _, _))| (label == *field).then_some(current));
 
- let struct_index = index.expect("field not in its own type");
+ let struct_index = match index {
+ Some(index) => index as u64,
+ None => return NotASymbol,
+ };
 
  let struct_symbol = possible_reuse_symbol_or_specialize(
  env,