normalize_languages/
nix.rs

1//! Nix language support.
2
3use std::path::Path;
4
5use crate::{
6    Import, ImportSpec, Language, LanguageSymbols, ModuleId, ModuleResolver, Resolution,
7    ResolverConfig,
8};
9use tree_sitter::Node;
10
11/// Nix language support.
12pub struct Nix;
13
14impl Language for Nix {
15    fn name(&self) -> &'static str {
16        "Nix"
17    }
18    fn extensions(&self) -> &'static [&'static str] {
19        &["nix"]
20    }
21    fn grammar_name(&self) -> &'static str {
22        "nix"
23    }
24
25    fn as_symbols(&self) -> Option<&dyn LanguageSymbols> {
26        Some(self)
27    }
28
29    fn extract_imports(&self, node: &Node, content: &str) -> Vec<Import> {
30        if node.kind() != "apply_expression" {
31            return Vec::new();
32        }
33
34        let text = &content[node.byte_range()];
35        if !text.starts_with("import ") {
36            return Vec::new();
37        }
38
39        // Extract path after "import"
40        let rest = text.strip_prefix("import ").unwrap_or("").trim();
41        let module = rest.split_whitespace().next().unwrap_or(rest).to_string();
42
43        vec![Import {
44            module,
45            names: Vec::new(),
46            alias: None,
47            is_wildcard: false,
48            is_relative: rest.starts_with('.'),
49            line: node.start_position().row + 1,
50        }]
51    }
52
53    fn format_import(&self, import: &Import, _names: Option<&[&str]>) -> String {
54        // Nix: import ./path.nix
55        format!("import {}", import.module)
56    }
57
58    fn is_test_symbol(&self, symbol: &crate::Symbol) -> bool {
59        let name = symbol.name.as_str();
60        match symbol.kind {
61            crate::SymbolKind::Function | crate::SymbolKind::Method => name.starts_with("test_"),
62            crate::SymbolKind::Module => name == "tests" || name == "test",
63            _ => false,
64        }
65    }
66
67    fn node_name<'a>(&self, node: &Node, content: &'a str) -> Option<&'a str> {
68        node.child_by_field_name("attrpath")
69            .map(|n| &content[n.byte_range()])
70    }
71
72    fn module_resolver(&self) -> Option<&dyn ModuleResolver> {
73        static RESOLVER: NixModuleResolver = NixModuleResolver;
74        Some(&RESOLVER)
75    }
76}
77
78impl LanguageSymbols for Nix {}
79
80// =============================================================================
81// Nix Module Resolver
82// =============================================================================
83
84/// Module resolver for Nix.
85///
86/// Nix has no module system — `import` is a file path operation. Relative paths
87/// (`./foo.nix`, `../lib/default.nix`) are resolved against the caller's directory.
88/// Channel/nixpkgs imports (`<nixpkgs>`) are returned as `NotFound` because they
89/// require nix evaluation to resolve.
90pub struct NixModuleResolver;
91
92impl ModuleResolver for NixModuleResolver {
93    fn workspace_config(&self, root: &Path) -> ResolverConfig {
94        ResolverConfig {
95            workspace_root: root.to_path_buf(),
96            path_mappings: Vec::new(),
97            search_roots: Vec::new(),
98        }
99    }
100
101    fn module_of_file(&self, _root: &Path, file: &Path, cfg: &ResolverConfig) -> Vec<ModuleId> {
102        let ext = file.extension().and_then(|e| e.to_str()).unwrap_or("");
103        if ext != "nix" {
104            return Vec::new();
105        }
106
107        let rel = file.strip_prefix(&cfg.workspace_root).unwrap_or(file);
108        let path_str = rel.to_string_lossy().into_owned();
109        if path_str.is_empty() {
110            return Vec::new();
111        }
112        vec![ModuleId {
113            canonical_path: path_str,
114        }]
115    }
116
117    fn resolve(&self, from_file: &Path, spec: &ImportSpec, cfg: &ResolverConfig) -> Resolution {
118        let ext = from_file.extension().and_then(|e| e.to_str()).unwrap_or("");
119        if ext != "nix" {
120            return Resolution::NotApplicable;
121        }
122
123        let raw = &spec.raw;
124
125        // Channel form: <nixpkgs>, <nixpkgs/pkgs/...> — not resolvable
126        if raw.starts_with('<') {
127            return Resolution::NotFound;
128        }
129
130        // Relative paths: ./foo.nix or ../lib/default.nix
131        if raw.starts_with("./") || raw.starts_with("../") {
132            let base_dir = from_file.parent().unwrap_or(&cfg.workspace_root);
133            let candidate = base_dir.join(raw);
134            if candidate.exists() {
135                return Resolution::Resolved(candidate, String::new());
136            }
137            return Resolution::NotFound;
138        }
139
140        // Bare name (e.g. `nixpkgs`) — not resolvable without nix toolchain
141        Resolution::NotFound
142    }
143}
144
145#[cfg(test)]
146mod tests {
147    use super::*;
148    use crate::validate_unused_kinds_audit;
149
150    #[test]
151    fn unused_node_kinds_audit() {
152        #[rustfmt::skip]
153        let documented_unused: &[&str] = &[
154            "assert_expression", "binary_expression", "float_expression",
155            "formal", "formals", "has_attr_expression", "hpath_expression",
156            "identifier", "indented_string_expression", "integer_expression",
157            "list_expression", "let_attrset_expression", "parenthesized_expression",
158            "path_expression", "select_expression", "spath_expression",
159            "string_expression", "unary_expression", "uri_expression",
160            "variable_expression",
161            // Control flow / application — not definition constructs
162            "apply_expression", "if_expression", "with_expression",
163            // structural node, not extracted as symbols
164            "let_expression",
165            "attrset_expression",
166            "rec_attrset_expression",
167            "function_expression",
168        ];
169        validate_unused_kinds_audit(&Nix, documented_unused)
170            .expect("Nix unused node kinds audit failed");
171    }
172}
normalize_languages/nix.rs

normalize_languages/
nix.rs
