alint_rules/
file_min_size.rs

1//! `file_min_size` — files in scope must be at least `min_bytes` bytes.
2//!
3//! Symmetric counterpart of [`file_max_size`](crate::file_max_size).
4//! The primary use case is "my README is more than a stub" /
5//! "my LICENSE text is not empty": a non-zero minimum size
6//! catches placeholder files that pass existence checks but add
7//! no information.
8//!
9//! Empty files are a likely separate problem; if you want to
10//! explicitly forbid those, use
11//! [`no_empty_files`](crate::no_empty_files) — `file_min_size:
12//! 1` works too but the dedicated rule carries clearer intent.
13
14use alint_core::{Context, Error, Level, Result, Rule, RuleSpec, Scope, Violation};
15use serde::Deserialize;
16
17#[derive(Debug, Deserialize)]
18struct Options {
19    min_bytes: u64,
20}
21
22#[derive(Debug)]
23pub struct FileMinSizeRule {
24    id: String,
25    level: Level,
26    policy_url: Option<String>,
27    message: Option<String>,
28    scope: Scope,
29    min_bytes: u64,
30}
31
32impl Rule for FileMinSizeRule {
33    fn id(&self) -> &str {
34        &self.id
35    }
36    fn level(&self) -> Level {
37        self.level
38    }
39    fn policy_url(&self) -> Option<&str> {
40        self.policy_url.as_deref()
41    }
42
43    fn evaluate(&self, ctx: &Context<'_>) -> Result<Vec<Violation>> {
44        let mut violations = Vec::new();
45        for entry in ctx.index.files() {
46            if !self.scope.matches(&entry.path) {
47                continue;
48            }
49            if entry.size < self.min_bytes {
50                let msg = self.message.clone().unwrap_or_else(|| {
51                    format!(
52                        "file below {} byte(s) (actual: {})",
53                        self.min_bytes, entry.size,
54                    )
55                });
56                violations.push(Violation::new(msg).with_path(entry.path.clone()));
57            }
58        }
59        Ok(violations)
60    }
61}
62
63pub fn build(spec: &RuleSpec) -> Result<Box<dyn Rule>> {
64    let Some(paths) = &spec.paths else {
65        return Err(Error::rule_config(
66            &spec.id,
67            "file_min_size requires a `paths` field",
68        ));
69    };
70    let opts: Options = spec
71        .deserialize_options()
72        .map_err(|e| Error::rule_config(&spec.id, format!("invalid options: {e}")))?;
73    Ok(Box::new(FileMinSizeRule {
74        id: spec.id.clone(),
75        level: spec.level,
76        policy_url: spec.policy_url.clone(),
77        message: spec.message.clone(),
78        scope: Scope::from_paths_spec(paths)?,
79        min_bytes: opts.min_bytes,
80    }))
81}
82
83#[cfg(test)]
84mod tests {
85    use super::*;
86    use crate::test_support::{ctx, spec_yaml};
87    use alint_core::{FileEntry, FileIndex};
88    use std::path::Path;
89
90    fn idx_with_size(path: &str, size: u64) -> FileIndex {
91        FileIndex {
92            entries: vec![FileEntry {
93                path: std::path::Path::new(path).into(),
94                is_dir: false,
95                size,
96            }],
97        }
98    }
99
100    #[test]
101    fn build_rejects_missing_paths_field() {
102        let spec = spec_yaml(
103            "id: t\n\
104             kind: file_min_size\n\
105             min_bytes: 100\n\
106             level: warning\n",
107        );
108        assert!(build(&spec).is_err());
109    }
110
111    #[test]
112    fn evaluate_passes_when_size_above_minimum() {
113        let spec = spec_yaml(
114            "id: t\n\
115             kind: file_min_size\n\
116             paths: \"README.md\"\n\
117             min_bytes: 100\n\
118             level: warning\n",
119        );
120        let rule = build(&spec).unwrap();
121        let idx = idx_with_size("README.md", 1024);
122        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
123        assert!(v.is_empty());
124    }
125
126    #[test]
127    fn evaluate_fires_when_size_below_minimum() {
128        let spec = spec_yaml(
129            "id: t\n\
130             kind: file_min_size\n\
131             paths: \"README.md\"\n\
132             min_bytes: 100\n\
133             level: warning\n",
134        );
135        let rule = build(&spec).unwrap();
136        let idx = idx_with_size("README.md", 10);
137        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
138        assert_eq!(v.len(), 1);
139    }
140
141    #[test]
142    fn evaluate_size_at_exact_minimum_passes() {
143        // Boundary: `entry.size < min_bytes` is strict, so a
144        // file at exactly min_bytes passes.
145        let spec = spec_yaml(
146            "id: t\n\
147             kind: file_min_size\n\
148             paths: \"a.bin\"\n\
149             min_bytes: 100\n\
150             level: warning\n",
151        );
152        let rule = build(&spec).unwrap();
153        let idx = idx_with_size("a.bin", 100);
154        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
155        assert!(v.is_empty(), "size == min should pass: {v:?}");
156    }
157
158    #[test]
159    fn evaluate_zero_byte_file_fires_when_minimum_positive() {
160        let spec = spec_yaml(
161            "id: t\n\
162             kind: file_min_size\n\
163             paths: \"empty.txt\"\n\
164             min_bytes: 1\n\
165             level: warning\n",
166        );
167        let rule = build(&spec).unwrap();
168        let idx = idx_with_size("empty.txt", 0);
169        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
170        assert_eq!(v.len(), 1);
171    }
172}
alint_rules/file_min_size.rs

alint_rules/
file_min_size.rs
