first header parse report test

compiler/parse/src/module.rs

@@ -308,7 +308,7 @@ pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>, SyntaxErr
     // force that we pare until the end of the input
     skip_second!(zero_or_more!(space0_around(loc(def(0)), 0)), end_of_file())
 }
-
+#[derive(Debug)]
 struct ProvidesTo<'a> {
     entries: Vec<'a, Located<ExposesEntry<'a, &'a str>>>,
     to: Located<To<'a>>,

compiler/reporting/src/error/parse.rs

@@ -153,6 +153,7 @@ fn to_syntax_report<'a>(
             0,
             0,
         ),
+        Header(header) => to_header_report(alloc, filename, &header, 0, 0),
         _ => todo!("unhandled parse error: {:?}", parse_problem),
     }
 }
@@ -2469,6 +2470,62 @@ fn to_tapply_report<'a>(
     }
 }
 
+fn to_header_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EHeader,
+    _start_row: Row,
+    _start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EHeader;
+
+    match *parse_problem {
+        EHeader::Provides(provides, row, col) => {
+            to_provides_report(alloc, filename, &provides, row, col)
+        } // _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
+fn to_provides_report<'a>(
+    alloc: &'a RocDocAllocator<'a>,
+    filename: PathBuf,
+    parse_problem: &roc_parse::parser::EProvides,
+    start_row: Row,
+    start_col: Col,
+) -> Report<'a> {
+    use roc_parse::parser::EProvides;
+
+    match *parse_problem {
+        EProvides::Identifier(row, col) => {
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(
+                    r"I am in the middle of parsing a provides list, but I got stuck here:",
+                ),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![alloc.reflow(
+                    "I was expecting a type name, value name or function name next, like ",
+                )]),
+                alloc
+                    .parser_suggestion("provides [ Animal, default, tame ]")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "WEIRD PROVIDES".to_string(),
+            }
+        }
+
+        EProvides::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
+
+        _ => todo!("unhandled parse error {:?}", parse_problem),
+    }
+}
+
 fn to_space_report<'a>(
     alloc: &'a RocDocAllocator<'a>,
     filename: PathBuf,

compiler/reporting/tests/test_reporting.rs

@@ -5767,19 +5767,22 @@ mod test_reporting {
                 app "test-base64"
                     packages { base: "platform" }
                     imports [base.Task, Base64 ]
-                    provides [ main, ## ] to base
+                    provides [ main, @Foo ] to base
                 "#
             ),
             indoc!(
                 r#"
-                ── MISSING EXPRESSION ──────────────────────────────────────────────────────────
-
-                I am partway through parsing a definition, but I got stuck here:
-
-                1│  main = 5 -> 3
-                              ^
-
-                I was expecting to see an expression like 42 or "hello".
+                ── WEIRD PROVIDES ──────────────────────────────────────────────────────────────
+                
+                I am in the middle of parsing a provides list, but I got stuck here:
+                
+                3│      imports [base.Task, Base64 ]
+                4│      provides [ main, @Foo ] to base
+                                         ^
+                
+                I was expecting a type name, value name or function name next, like 
+                
+                    provides [ Animal, default, tame ]
             "#
             ),
         )