feat(xatu): add scope graph

src/xatu/BUILD

@@ -8,7 +8,6 @@ rust_library(
         "file_store.rs",
         "parser.rs",
         "rules.rs",
-        "rules/let_order.rs",
         "rules/manual_inherit.rs",
         "rules/manual_inherit_from.rs",
         "rules/unquoted_uri.rs",

src/xatu/rules.rs

@@ -3,9 +3,7 @@ use crate::ast;
 use crate::rules::manual_inherit::ManualInherit;
 use crate::rules::manual_inherit_from::ManualInheritFrom;
 use crate::rules::unquoted_uri::UnquotedUri;
-use crate::scope_graph::ScopeGraph;
 
-pub mod let_order;
 pub mod manual_inherit;
 pub mod manual_inherit_from;
 pub mod unquoted_uri;
@@ -21,22 +19,15 @@ pub struct Finding {
     pub rule_id: &'static str,
     pub range: ast::SourceRange,
     pub message: &'static str,
-    pub binding: Option<String>,
 }
 
 impl std::fmt::Display for Diagnostic {
     fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(
             formatter,
-            "[{}] {}",
-            self.finding.rule_id, self.finding.message
-        )?;
-
-        if let Some(binding) = &self.finding.binding {
-            write!(formatter, ": {binding}")?;
-        }
-
-        Ok(())
+            "{}: {}: {}",
+            self.finding.range, self.finding.rule_id, self.finding.message,
+        )
     }
 }
 
@@ -58,7 +49,7 @@ pub trait TokenRule {
     fn check(token: &Self::Token) -> Option<&'static str>;
 }
 
-pub fn run_rules(file: &ast::ParsedFile, graph: &ScopeGraph) -> Vec<Diagnostic> {
+pub fn run_rules(file: &ast::ParsedFile) -> Vec<Diagnostic> {
     let node_diagnostics = file
         .nodes
         .iter()
@@ -75,16 +66,8 @@ pub fn run_rules(file: &ast::ParsedFile, graph: &ScopeGraph) -> Vec<Diagnostic>
         .flat_map(|token| [run_token_rule::<UnquotedUri>(token)])
         .flatten();
 
-    let let_order_diagnostics = let_order::check(graph).into_iter().map(|finding| Finding {
-        rule_id: "let_order",
-        range: finding.range,
-        message: "Let bindings must follow dependency order",
-        binding: Some(finding.binding),
-    });
-
     node_diagnostics
         .chain(token_diagnostics)
-        .chain(let_order_diagnostics)
         .map(|finding| Diagnostic {
             file_id: file.file_id,
             finding,
@@ -103,7 +86,6 @@ where
         rule_id: R::ID,
         range: node.range,
         message,
-        binding: None,
     })
 }
 
@@ -118,6 +100,5 @@ where
         rule_id: R::ID,
         range: token.range,
         message,
-        binding: None,
     })
 }

src/xatu/rules/let_order.rs

@@ -1,71 +0,0 @@
-use crate::{
-    ast,
-    scope_graph::{LetScope, NodeId, ScopeGraph},
-};
-
-pub struct Finding {
-    pub range: ast::SourceRange,
-    pub binding: String,
-}
-
-pub fn check(graph: &ScopeGraph) -> Vec<Finding> {
-    graph
-        .let_scopes()
-        .iter()
-        .flat_map(|let_scope| {
-            let expected = expected_order(graph, let_scope);
-            let positions = expected
-                .iter()
-                .enumerate()
-                .map(|(position, declaration)| (*declaration, position))
-                .collect::<Vec<_>>();
-
-            let_scope
-                .bindings
-                .iter()
-                .enumerate()
-                .filter_map(move |(position, binding)| {
-                    positions
-                        .iter()
-                        .find(|(declaration, _)| *declaration == binding.declaration)
-                        .filter(|(_, expected_position)| position != *expected_position)
-                        .map(|_| Finding {
-                            range: binding.range,
-                            binding: binding.name.clone(),
-                        })
-                })
-        })
-        .collect()
-}
-
-fn expected_order(graph: &ScopeGraph, let_scope: &LetScope) -> Vec<NodeId> {
-    let mut order = Vec::new();
-    visit_references(graph, &let_scope.entry_references, let_scope, &mut order);
-    order
-}
-
-fn visit_references(
-    graph: &ScopeGraph,
-    references: &[NodeId],
-    let_scope: &LetScope,
-    order: &mut Vec<NodeId>,
-) {
-    for reference in references {
-        for declaration in graph.resolve(*reference) {
-            let Some(binding) = let_scope
-                .bindings
-                .iter()
-                .find(|binding| binding.declaration == declaration)
-            else {
-                continue;
-            };
-
-            if order.contains(&declaration) {
-                continue;
-            }
-
-            order.push(declaration);
-            visit_references(graph, &binding.references, let_scope, order);
-        }
-    }
-}

src/xatu/testdata/clean.nix

@@ -1,22 +1,6 @@
 { pkgs }:
 
-let
-  first = 1;
-  second = first;
-in {
-  firstField = first;
-  secondField = second;
-  nested = let
-    innerSecond = innerFirst;
-    innerFirst = first;
-  in {
-    result = innerSecond;
-  };
-  parameter = first: let
-    usesParameter = first;
-  in {
-    result = usesParameter;
-  };
+{
   path = ./. + "/foo";
   url = "https://example.com";
   inherit pkgs;

src/xatu/testdata/lint_findings.nix

@@ -1,17 +1,5 @@
-let
-  second = first;
-  first = 1;
-  nested = let
-    nestedFirst = first;
-    nestedSecond = nestedFirst;
-  in {
-    result = nestedSecond;
-  };
-in {
+{
   package = package;
   from = pkgs.from;
   url = https://example.com;
-  firstField = first;
-  secondField = second;
-  nestedField = nested;
 }

src/xatu/xatu.rs

@@ -4,8 +4,6 @@ mod parser;
 mod rules;
 mod scope_graph;
 
-use scope_graph::ScopeGraph;
-
 pub use file_store::{FileId, FileStore, SourceFile};
 pub use rules::{Diagnostic, Finding};
 
@@ -25,34 +23,13 @@ impl std::fmt::Display for Report {
     fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         for diagnostic in &self.diagnostics {
             let file = self.files.get(diagnostic.file_id);
-            let (start, end) = line_range(&file.source, diagnostic.finding.range);
-            let location = if start == end {
-                start.to_string()
-            } else {
-                format!("{start}-{end}")
-            };
-            writeln!(formatter, "{}:{location} {diagnostic}", file.path.display())?;
+            writeln!(formatter, "{}:{diagnostic}", file.path.display())?;
         }
 
         Ok(())
     }
 }
 
-fn line_range(source: &str, range: ast::SourceRange) -> (usize, usize) {
-    let line_at = |offset| {
-        source
-            .bytes()
-            .take(offset)
-            .filter(|byte| *byte == b'\n')
-            .count()
-            + 1
-    };
-    let start = line_at(range.start);
-    let end = line_at(range.end);
-
-    (start, end)
-}
-
 /// Analyzes source files and returns the diagnostics Xatu finds.
 pub fn future_sight(files: Vec<SourceFile>) -> status::Result<Report> {
     let mut store = FileStore::default();
@@ -70,8 +47,7 @@ pub fn future_sight(files: Vec<SourceFile>) -> status::Result<Report> {
             )));
         }
 
-        let graph = ScopeGraph::from_file(&parsed);
-        diagnostics.extend(rules::run_rules(&parsed, &graph));
+        diagnostics.extend(rules::run_rules(&parsed));
     }
 
     Ok(Report {

src/xatu/xatu_test.rs

@@ -41,19 +41,6 @@ fn xatu_rejects_invalid_source() -> googletest::Result<()> {
     Ok(())
 }
 
-#[gtest]
-fn xatu_reports_out_of_order_let_bindings() -> googletest::Result<()> {
-    let report = xatu::future_sight(vec![fixture_source("testdata/lint_findings.nix")?]).or_fail()?;
-
-    let let_order_count = report
-        .diagnostics
-        .iter()
-        .filter(|diagnostic| diagnostic.finding.rule_id == "let_order")
-        .count();
-    expect_that!(let_order_count, eq(4));
-    Ok(())
-}
-
 #[gtest]
 fn xatu_reports_unquoted_uri() -> googletest::Result<()> {
     let report = xatu::future_sight(vec![fixture_source("testdata/lint_findings.nix")?]).or_fail()?;