Start fixing error outputs

Signed-off-by: Marcel Müller <neikos@neikos.email>

benches/asting.rs

@@ -1,3 +1,5 @@
+#![allow(missing_docs)]
+
 use criterion::BenchmarkId;
 use criterion::Criterion;
 use criterion::criterion_group;

benches/parsing.rs

@@ -1,3 +1,5 @@
+#![allow(missing_docs)]
+
 use criterion::BenchmarkId;
 use criterion::Criterion;
 use criterion::criterion_group;

src/compiler/mod.rs

@@ -63,7 +63,7 @@ pub enum Instruction {
         slot: VariableSlot,
     },
     PushScope {
-        #[expect(unused)]
+        #[allow(unused)]
         inherit_parent: bool,
     },
     Abort,

src/errors.rs

@@ -5,11 +5,13 @@ use annotate_snippets::Level;
 use annotate_snippets::Renderer;
 use annotate_snippets::Snippet;
 use thiserror::Error;
+use winnow::stream::Offset;
 
 use crate::input::NomoInput;
 use crate::lexer::ParseError;
 use crate::parser::AstError;
 
+/// An error occurred while producing an Ast
 #[derive(Debug, Error)]
 pub struct AstFailure {
     errors: Vec<AstError>,
@@ -26,6 +28,7 @@ impl AstFailure {
         AstFailure { errors }
     }
 
+    /// Create a CLI printable report
     pub fn to_report(&self, source: &str) -> String {
         let reports = self
             .errors
@@ -38,12 +41,14 @@ impl AstFailure {
                             .as_deref()
                             .unwrap_or("An error occurred while producing an Ast"),
                     )
-                    .element(
-                        annotate_snippets::Snippet::source(source).annotation(
-                            annotate_snippets::AnnotationKind::Primary
-                                .span(error.span.clone().map(|s| s.range).unwrap_or_else(|| 0..0)),
+                    .element(annotate_snippets::Snippet::source(source).annotation(
+                        annotate_snippets::AnnotationKind::Primary.span(
+                            constrain_without_whitespace(
+                                source,
+                                error.span.clone().map(|s| s.range).unwrap_or_else(|| 0..0),
+                            ),
                         ),
-                    )
+                    ))
                     .elements(
                         error
                             .help
@@ -59,6 +64,18 @@ impl AstFailure {
     }
 }
 
+fn constrain_without_whitespace(
+    input: &str,
+    range: std::ops::Range<usize>,
+) -> std::ops::Range<usize> {
+    let trimmed = input[range].trim();
+    let start = trimmed.offset_from(&input);
+    let end = start + trimmed.len();
+
+    start..end
+}
+
+/// An error occurred during lexing
 #[derive(Debug, Error)]
 pub struct ParseFailure {
     input: Arc<str>,
@@ -79,6 +96,7 @@ impl ParseFailure {
         }
     }
 
+    /// Produce a CLi printable report
     pub fn to_report(&self) -> String {
         let reports = self
             .errors

src/functions.rs

@@ -34,6 +34,7 @@ pub trait NomoFunction<T>: 'static + Send + Sync {
 
 #[cfg(feature = "unstable-pub")]
 #[derive(Default)]
+#[expect(missing_docs)]
 pub struct FunctionMap {
     funcs: HashMap<String, ErasedNomoFunction>,
 }
@@ -45,6 +46,7 @@ pub(crate) struct FunctionMap {
 }
 
 impl FunctionMap {
+    #[expect(missing_docs)]
     pub fn register<NF: NomoFunction<T>, T>(&mut self, name: impl Into<String>, func: NF) {
         self.funcs
             .insert(name.into(), ErasedNomoFunction::erase(func));

src/lexer/mod.rs

@@ -1,10 +1,3 @@
-use std::sync::Arc;
-
-use annotate_snippets::AnnotationKind;
-use annotate_snippets::Level;
-use annotate_snippets::Renderer;
-use annotate_snippets::Snippet;
-use thiserror::Error;
 use winnow::LocatingSlice;
 use winnow::Parser;
 use winnow::RecoverableParser;

src/lib.rs

@@ -113,6 +113,7 @@ macro_rules! unstable_pub {
     ($(#[$m:meta])* mod $name:ident) => {
         $(#[$m])*
         #[cfg(feature = "unstable-pub")]
+        #[allow(missing_docs)]
         pub mod $name;
         #[cfg(not(feature = "unstable-pub"))]
         mod $name;

src/parser/mod.rs

@@ -104,13 +104,14 @@ impl FromRecoverableError<Input<'_>, AstError> for AstError {
                 .filter(|t| t.kind() != TokenKind::Whitespace);
             let last = tokens.next();
             let first = tokens.last();
+
             match (last, first) {
                 (None, None) => None,
                 (None, Some(single)) | (Some(single), None) => Some(SourceSpan {
                     range: single.source().get_range(),
                 }),
                 (Some(last), Some(first)) => {
-                    let start = first.source().get_range().start;
+                    let start = first.source().get_range().end;
                     let end = last.source().get_range().end;
 
                     Some(SourceSpan { range: start..end })
@@ -212,7 +213,7 @@ pub enum TemplateAstExpr<'input> {
     ElseConditional {
         expression: Option<Box<TemplateAstExpr<'input>>>,
     },
-    #[expect(unused)]
+    #[allow(unused)]
     Invalid(&'input [TemplateToken]),
     MathOperation {
         op: TokenOperator,
@@ -311,7 +312,7 @@ fn parse_action<'input>(input: &mut Input<'input>) -> Result<TemplateAstExpr<'in
             (parse_block(
                 cut_err(not(repeat_till(
                     0..,
-                    any,
+                    parse_expression,
                     peek((ws, TokenKind::RightDelim)),
                 )
                 .map(|((), _)| ())))
@@ -342,7 +343,7 @@ fn parse_for_chain<'input>(input: &mut Input<'input>) -> Result<TemplateAstExpr<
 
         let (content, taken) = resume_after_cut(
             repeat_till(0.., parse_ast, loop_end),
-            repeat_till(0.., any, parse_end).map(|((), _)| ()),
+            repeat_till(0.., parse_ast, parse_end).map(|((), _)| ()),
         )
         .with_taken()
         .parse_next(input)?;
@@ -372,9 +373,11 @@ fn parse_for_loop<'input>(input: &mut Input<'input>) -> Result<TemplateAstExpr<'
                 ws,
                 TokenKind::For,
                 ws,
-                TokenKind::Ident,
+                cut_err(TokenKind::Ident.context(AstError::ctx().msg("Expected identifier here"))),
                 ws,
-                TokenKind::In,
+                cut_err(
+                    TokenKind::In.context(AstError::ctx().msg("Missing `in` in `for _ in <expr>`")),
+                ),
                 ws,
                 parse_expression.map(Box::new),
             )
@@ -601,11 +604,34 @@ where
 fn parse_operand<'input>(input: &mut Input<'input>) -> Result<TemplateAstExpr<'input>, AstError> {
     trace(
         "operand",
-        alt((parse_function, parse_variable_access, parse_literal)),
+        alt((
+            parse_keywords_fail,
+            parse_function,
+            parse_variable_access,
+            parse_literal,
+        )),
     )
     .parse_next(input)
 }
 
+fn parse_keywords_fail<'input>(
+    input: &mut Input<'input>,
+) -> Result<TemplateAstExpr<'input>, AstError> {
+    let value = alt((
+        TokenKind::ConditionalIf,
+        TokenKind::For,
+        TokenKind::End,
+        TokenKind::In,
+    ))
+    .take()
+    .map(TemplateAstExpr::Invalid)
+    .parse_next(input)?;
+
+    cut_err(fail::<_, (), _>.context(AstError::ctx().msg("Found literal, expected expression")))
+        .value(value)
+        .parse_next(input)
+}
+
 fn parse_literal<'input>(input: &mut Input<'input>) -> Result<TemplateAstExpr<'input>, AstError> {
     trace(
         "literal",
@@ -895,7 +921,7 @@ mod tests {
                     help: None,
                     span: Some(
                         SourceSpan {
-                            range: 0..6,
+                            range: 2..6,
                         },
                     ),
                     is_fatal: false,

tests/checks.rs

@@ -1,3 +1,5 @@
+#![allow(missing_docs)]
+
 #[test]
 fn check_files() {
     let files = std::fs::read_dir("tests/checks/").unwrap();

tests/errors/invalid_controls.1-parsed.snap

@@ -0,0 +1,106 @@
+---
+source: tests/file_tests.rs
+expression: parsed
+info:
+  input: "{{ if }} {{ end }}\n{{ if if }} {{ end }}\n{{ if if }} {{ for foo in bar }} {{ end }} {{ end }}\n{{ for in bar }} {{ end }}\n{{ for blah bar }} {{ end }}\n{{ else }}"
+  context: {}
+---
+ParsedTemplate {
+    tokens: [
+        [LeftDelim]"{{" (0..2),
+        [Whitespace]" " (2..3),
+        [ConditionalIf]"if" (3..5),
+        [Whitespace]" " (5..6),
+        [RightDelim]"}}" (6..8),
+        [Whitespace]" " (8..9),
+        [LeftDelim]"{{" (9..11),
+        [Whitespace]" " (11..12),
+        [End]"end" (12..15),
+        [Whitespace]" " (15..16),
+        [RightDelim]"}}" (16..18),
+        [Whitespace]"\n" (18..19),
+        [LeftDelim]"{{" (19..21),
+        [Whitespace]" " (21..22),
+        [ConditionalIf]"if" (22..24),
+        [Whitespace]" " (24..25),
+        [ConditionalIf]"if" (25..27),
+        [Whitespace]" " (27..28),
+        [RightDelim]"}}" (28..30),
+        [Whitespace]" " (30..31),
+        [LeftDelim]"{{" (31..33),
+        [Whitespace]" " (33..34),
+        [End]"end" (34..37),
+        [Whitespace]" " (37..38),
+        [RightDelim]"}}" (38..40),
+        [Whitespace]"\n" (40..41),
+        [LeftDelim]"{{" (41..43),
+        [Whitespace]" " (43..44),
+        [ConditionalIf]"if" (44..46),
+        [Whitespace]" " (46..47),
+        [ConditionalIf]"if" (47..49),
+        [Whitespace]" " (49..50),
+        [RightDelim]"}}" (50..52),
+        [Whitespace]" " (52..53),
+        [LeftDelim]"{{" (53..55),
+        [Whitespace]" " (55..56),
+        [For]"for" (56..59),
+        [Whitespace]" " (59..60),
+        [Ident]"foo" (60..63),
+        [Whitespace]" " (63..64),
+        [In]"in" (64..66),
+        [Whitespace]" " (66..67),
+        [Ident]"bar" (67..70),
+        [Whitespace]" " (70..71),
+        [RightDelim]"}}" (71..73),
+        [Whitespace]" " (73..74),
+        [LeftDelim]"{{" (74..76),
+        [Whitespace]" " (76..77),
+        [End]"end" (77..80),
+        [Whitespace]" " (80..81),
+        [RightDelim]"}}" (81..83),
+        [Whitespace]" " (83..84),
+        [LeftDelim]"{{" (84..86),
+        [Whitespace]" " (86..87),
+        [End]"end" (87..90),
+        [Whitespace]" " (90..91),
+        [RightDelim]"}}" (91..93),
+        [Whitespace]"\n" (93..94),
+        [LeftDelim]"{{" (94..96),
+        [Whitespace]" " (96..97),
+        [For]"for" (97..100),
+        [Whitespace]" " (100..101),
+        [In]"in" (101..103),
+        [Whitespace]" " (103..104),
+        [Ident]"bar" (104..107),
+        [Whitespace]" " (107..108),
+        [RightDelim]"}}" (108..110),
+        [Whitespace]" " (110..111),
+        [LeftDelim]"{{" (111..113),
+        [Whitespace]" " (113..114),
+        [End]"end" (114..117),
+        [Whitespace]" " (117..118),
+        [RightDelim]"}}" (118..120),
+        [Whitespace]"\n" (120..121),
+        [LeftDelim]"{{" (121..123),
+        [Whitespace]" " (123..124),
+        [For]"for" (124..127),
+        [Whitespace]" " (127..128),
+        [Ident]"blah" (128..132),
+        [Whitespace]" " (132..133),
+        [Ident]"bar" (133..136),
+        [Whitespace]" " (136..137),
+        [RightDelim]"}}" (137..139),
+        [Whitespace]" " (139..140),
+        [LeftDelim]"{{" (140..142),
+        [Whitespace]" " (142..143),
+        [End]"end" (143..146),
+        [Whitespace]" " (146..147),
+        [RightDelim]"}}" (147..149),
+        [Whitespace]"\n" (149..150),
+        [LeftDelim]"{{" (150..152),
+        [Whitespace]" " (152..153),
+        [ConditionalElse]"else" (153..157),
+        [Whitespace]" " (157..158),
+        [RightDelim]"}}" (158..160),
+    ],
+}

tests/errors/invalid_controls.2-ast.snap

@@ -0,0 +1,32 @@
+---
+source: tests/file_tests.rs
+expression: ast
+info:
+  input: "{{ if }} {{ end }}\n{{ if if }} {{ end }}\n{{ if if }} {{ for foo in bar }} {{ end }} {{ end }}\n{{ for in bar }} {{ end }}\n{{ for blah bar }} {{ end }}\n{{ else }}"
+  context: {}
+---
+error: Expected an expression after 'if'
+  ╭▸ 
+1 │ {{ if }} {{ end }}
+  │    ━━
+  ╰╴
+error: Expected an expression after 'if'
+  ╭▸ 
+2 │ {{ if if }} {{ end }}
+  ╰╴      ━━
+error: Expected an expression after 'if'
+  ╭▸ 
+3 │ {{ if if }} {{ for foo in bar }} {{ end }} {{ end }}
+  ╰╴      ━━
+error: Expected identifier here
+  ╭▸ 
+4 │ {{ for in bar }} {{ end }}
+  ╰╴       ━━━━━━
+error: Missing `in` in `for _ in <expr>`
+  ╭▸ 
+5 │ {{ for blah bar }} {{ end }}
+  ╰╴       ━━━━━━━━
+error: An error occurred while producing an Ast
+  ╭▸ 
+6 │ {{ else }}
+  ╰╴   ━━━━━━━

tests/errors/invalid_controls.nomo

@@ -0,0 +1,8 @@
+{}
+---
+{{ if }} {{ end }}
+{{ if if }} {{ end }}
+{{ if if }} {{ for foo in bar }} {{ end }} {{ end }}
+{{ for in bar }} {{ end }}
+{{ for blah bar }} {{ end }}
+{{ else }}

tests/errors/invalid_if.1-parsed.snap

@@ -0,0 +1,24 @@
+---
+source: tests/file_tests.rs
+expression: parsed
+info:
+  input: "{{ if if }} {{ end }}"
+  context: {}
+---
+ParsedTemplate {
+    tokens: [
+        [LeftDelim]"{{" (0..2),
+        [Whitespace]" " (2..3),
+        [ConditionalIf]"if" (3..5),
+        [Whitespace]" " (5..6),
+        [ConditionalIf]"if" (6..8),
+        [Whitespace]" " (8..9),
+        [RightDelim]"}}" (9..11),
+        [Whitespace]" " (11..12),
+        [LeftDelim]"{{" (12..14),
+        [Whitespace]" " (14..15),
+        [End]"end" (15..18),
+        [Whitespace]" " (18..19),
+        [RightDelim]"}}" (19..21),
+    ],
+}

tests/errors/invalid_if.2-ast.snap

@@ -0,0 +1,11 @@
+---
+source: tests/file_tests.rs
+expression: ast
+info:
+  input: "{{ if if }} {{ end }}"
+  context: {}
+---
+error: Expected an expression after 'if'
+  ╭▸ 
+1 │ {{ if if }} {{ end }}
+  ╰╴      ━━

tests/errors/invalid_if.nomo

@@ -0,0 +1,3 @@
+{}
+---
+{{ if if }} {{ end }}

tests/file_tests.rs

@@ -1,3 +1,5 @@
+#![allow(missing_docs)]
+
 use std::collections::HashMap;
 use std::path::Path;
 
@@ -6,6 +8,8 @@ use nomo::functions::FunctionMap;
 
 test_each_file::test_each_path! { for ["nomo"] in "./tests/cases/" as cases => check_for_input }
 
+test_each_file::test_each_path! { for ["nomo"] in "./tests/errors/" as error_cases => check_errors }
+
 #[derive(serde::Serialize)]
 struct Info {
     input: String,
@@ -63,3 +67,67 @@ fn check_for_input([path]: [&Path; 1]) {
 
     insta::assert_debug_snapshot!(format!("{basename}.4-output"), output);
 }
+
+fn check_errors([path]: [&Path; 1]) {
+    let mut settings = insta::Settings::clone_current();
+    settings.set_snapshot_path("errors");
+    settings.set_prepend_module_to_snapshot(false);
+
+    let basename = path.file_stem().unwrap().to_string_lossy();
+    let input = std::fs::read_to_string(path).unwrap();
+
+    let (context, input) = input.split_once("\n---\n").unwrap_or_else(|| ("", &input));
+
+    let map = if !context.is_empty() {
+        serde_json::from_str::<HashMap<String, serde_json::Value>>(context).unwrap()
+    } else {
+        HashMap::new()
+    };
+
+    settings.set_info(&Info {
+        input: input.to_string(),
+        context: map.clone(),
+    });
+
+    let mut context = Context::new();
+
+    for (k, v) in map {
+        context.try_insert(k, v).unwrap();
+    }
+
+    let _guard = settings.bind_to_scope();
+
+    let parsed = nomo::lexer::parse(input.into()).map_err(|err| err.to_report());
+
+    match &parsed {
+        Ok(parsed) => insta::assert_debug_snapshot!(format!("{basename}.1-parsed"), parsed),
+        Err(parsed) => insta::assert_snapshot!(format!("{basename}.1-parsed"), parsed),
+    }
+
+    let Ok(parsed) = parsed else {
+        return;
+    };
+
+    let ast = nomo::parser::parse(parsed.tokens()).map_err(|err| err.to_report(input));
+
+    match &ast {
+        Ok(ast) => insta::assert_debug_snapshot!(format!("{basename}.2-ast"), ast),
+        Err(ast) => insta::assert_snapshot!(format!("{basename}.2-ast"), ast),
+    }
+
+    let Ok(ast) = ast else {
+        return;
+    };
+
+    let emit = nomo::compiler::emit_machine(ast);
+
+    insta::assert_debug_snapshot!(format!("{basename}.3-instructions"), emit);
+
+    let output = nomo::eval::execute(&FunctionMap::default(), &emit, &context)
+        .map_err(|err| err.to_string());
+
+    match &output {
+        Ok(output) => insta::assert_debug_snapshot!(format!("{basename}.4-output"), output),
+        Err(output) => insta::assert_snapshot!(format!("{basename}.4-output"), output),
+    }
+}