feat: Improving error messages when parsin

Exclude suggestions to add 'start of file' :) Also renames `parse_single` to `parse_source`
PRQL · Jul 15, 2024 · 1f2006f · 1f2006f
1 parent c58fb33
commit 1f2006f
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Showing 3 changed files with 115 additions and 67 deletions.
diff --git a/prqlc/prqlc-parser/src/parser/expr.rs b/prqlc/prqlc-parser/src/parser/expr.rs
@@ -537,13 +537,56 @@ fn operator_coalesce() -> impl Parser<TokenKind, BinOp, Error = PError> + Clone
 #[cfg(test)]
 mod tests {
 
-    use insta::assert_yaml_snapshot;
+    use insta::{assert_debug_snapshot, assert_yaml_snapshot};
 
     use super::super::test::trim_start;
     use crate::test::parse_with_parser;
 
     use super::*;
 
+    #[test]
+    fn test_tuple() {
+        let tuple = || trim_start().ignore_then(tuple(expr()));
+        assert_yaml_snapshot!(
+            parse_with_parser(r#"{a = 5, b = 6}"#, tuple()).unwrap(),
+            @r###"
+        ---
+        Tuple:
+          - Literal:
+              Integer: 5
+            span: "0:5-6"
+            alias: a
+          - Literal:
+              Integer: 6
+            span: "0:12-13"
+            alias: b
+        "###);
+
+        assert_debug_snapshot!(
+            parse_with_parser(r#"
+            {a = 5
+             b = 6}"#, tuple()).unwrap_err(),
+            @r###"
+        [
+            Error {
+                kind: Error,
+                span: Some(
+                    0:33-34,
+                ),
+                reason: Expected {
+                    who: Some(
+                        "new line",
+                    ),
+                    expected: "}",
+                    found: "b",
+                },
+                hints: [],
+                code: None,
+            },
+        ]
+        "###);
+    }
+
     #[test]
     fn test_expr() {
         assert_yaml_snapshot!(

diff --git a/prqlc/prqlc-parser/src/parser/perror.rs b/prqlc/prqlc-parser/src/parser/perror.rs
@@ -222,8 +222,13 @@ impl From<PError> for Error {
                 .all(|t| matches!(t, None | Some(TokenKind::NewLine)));
             let expected: Vec<String> = e
                 .expected()
-                // Only include whitespace if we're _only_ expecting whitespace
-                .filter(|t| is_all_whitespace || !matches!(t, None | Some(TokenKind::NewLine)))
+                // Only include whitespace if we're _only_ expecting whitespace,
+                // otherwise we get "expected start of line or new line or }"
+                // when there's no ending `}`, since a new line is allowed.
+                .filter(|t| {
+                    is_all_whitespace
+                        || !matches!(t, None | Some(TokenKind::NewLine) | Some(TokenKind::Start))
+                })
                 .cloned()
                 .map(token_to_string)
                 .collect();