alint_rules/
file_max_size.rs

1//! `file_max_size` — files in scope must be at most `max_bytes` bytes.
2
3use alint_core::{Context, Error, Level, Result, Rule, RuleSpec, Scope, Violation};
4use serde::Deserialize;
5
6#[derive(Debug, Deserialize)]
7#[serde(deny_unknown_fields)]
8struct Options {
9    max_bytes: u64,
10}
11
12#[derive(Debug)]
13pub struct FileMaxSizeRule {
14    id: String,
15    level: Level,
16    policy_url: Option<String>,
17    message: Option<String>,
18    scope: Scope,
19    max_bytes: u64,
20}
21
22impl Rule for FileMaxSizeRule {
23    fn id(&self) -> &str {
24        &self.id
25    }
26    fn level(&self) -> Level {
27        self.level
28    }
29    fn policy_url(&self) -> Option<&str> {
30        self.policy_url.as_deref()
31    }
32
33    fn evaluate(&self, ctx: &Context<'_>) -> Result<Vec<Violation>> {
34        let mut violations = Vec::new();
35        for entry in ctx.index.files() {
36            if !self.scope.matches(&entry.path, ctx.index) {
37                continue;
38            }
39            if entry.size > self.max_bytes {
40                let msg = self.message.clone().unwrap_or_else(|| {
41                    format!(
42                        "file exceeds {} byte(s) (actual: {})",
43                        self.max_bytes, entry.size
44                    )
45                });
46                violations.push(Violation::new(msg).with_path(entry.path.clone()));
47            }
48        }
49        Ok(violations)
50    }
51}
52
53pub fn build(spec: &RuleSpec) -> Result<Box<dyn Rule>> {
54    let Some(_paths) = &spec.paths else {
55        return Err(Error::rule_config(
56            &spec.id,
57            "file_max_size requires a `paths` field",
58        ));
59    };
60    let opts: Options = spec
61        .deserialize_options()
62        .map_err(|e| Error::rule_config(&spec.id, format!("invalid options: {e}")))?;
63    Ok(Box::new(FileMaxSizeRule {
64        id: spec.id.clone(),
65        level: spec.level,
66        policy_url: spec.policy_url.clone(),
67        message: spec.message.clone(),
68        scope: Scope::from_spec(spec)?,
69        max_bytes: opts.max_bytes,
70    }))
71}
72
73#[cfg(test)]
74mod tests {
75    use super::*;
76    use crate::test_support::{ctx, spec_yaml};
77    use alint_core::{FileEntry, FileIndex};
78    use std::path::Path;
79
80    fn idx_with_size(path: &str, size: u64) -> FileIndex {
81        FileIndex::from_entries(vec![FileEntry {
82            path: std::path::Path::new(path).into(),
83            is_dir: false,
84            size,
85        }])
86    }
87
88    #[test]
89    fn build_rejects_missing_paths_field() {
90        let spec = spec_yaml(
91            "id: t\n\
92             kind: file_max_size\n\
93             max_bytes: 1000\n\
94             level: warning\n",
95        );
96        assert!(build(&spec).is_err());
97    }
98
99    #[test]
100    fn build_rejects_missing_max_bytes() {
101        let spec = spec_yaml(
102            "id: t\n\
103             kind: file_max_size\n\
104             paths: \"**/*\"\n\
105             level: warning\n",
106        );
107        assert!(build(&spec).is_err());
108    }
109
110    #[test]
111    fn evaluate_passes_when_size_under_limit() {
112        let spec = spec_yaml(
113            "id: t\n\
114             kind: file_max_size\n\
115             paths: \"**/*\"\n\
116             max_bytes: 100\n\
117             level: warning\n",
118        );
119        let rule = build(&spec).unwrap();
120        let idx = idx_with_size("a.bin", 50);
121        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
122        assert!(v.is_empty());
123    }
124
125    #[test]
126    fn evaluate_fires_when_size_over_limit() {
127        let spec = spec_yaml(
128            "id: t\n\
129             kind: file_max_size\n\
130             paths: \"**/*\"\n\
131             max_bytes: 100\n\
132             level: warning\n",
133        );
134        let rule = build(&spec).unwrap();
135        let idx = idx_with_size("big.bin", 1024);
136        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
137        assert_eq!(v.len(), 1);
138    }
139
140    #[test]
141    fn evaluate_size_at_exact_limit_passes() {
142        // Boundary: `entry.size > max_bytes` is strict, so a
143        // file at exactly max_bytes is OK.
144        let spec = spec_yaml(
145            "id: t\n\
146             kind: file_max_size\n\
147             paths: \"**/*\"\n\
148             max_bytes: 100\n\
149             level: warning\n",
150        );
151        let rule = build(&spec).unwrap();
152        let idx = idx_with_size("a.bin", 100);
153        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
154        assert!(v.is_empty(), "size == max should pass: {v:?}");
155    }
156
157    #[test]
158    fn scope_filter_narrows() {
159        // Two oversize files; only the one inside a directory
160        // with `marker.lock` as ancestor should fire.
161        let spec = spec_yaml(
162            "id: t\n\
163             kind: file_max_size\n\
164             paths: \"**/*.bin\"\n\
165             max_bytes: 100\n\
166             scope_filter:\n  \
167               has_ancestor: marker.lock\n\
168             level: warning\n",
169        );
170        let rule = build(&spec).unwrap();
171        let idx = FileIndex::from_entries(vec![
172            FileEntry {
173                path: std::path::Path::new("pkg/marker.lock").into(),
174                is_dir: false,
175                size: 1,
176            },
177            FileEntry {
178                path: std::path::Path::new("pkg/big.bin").into(),
179                is_dir: false,
180                size: 1024,
181            },
182            FileEntry {
183                path: std::path::Path::new("other/big.bin").into(),
184                is_dir: false,
185                size: 1024,
186            },
187        ]);
188        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
189        assert_eq!(v.len(), 1, "only in-scope file should fire: {v:?}");
190        assert_eq!(v[0].path.as_deref(), Some(Path::new("pkg/big.bin")));
191    }
192}
alint_rules/file_max_size.rs

alint_rules/
file_max_size.rs
