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::from_entries(vec![FileEntry {
92            path: std::path::Path::new(path).into(),
93            is_dir: false,
94            size,
95        }])
96    }
97
98    #[test]
99    fn build_rejects_missing_paths_field() {
100        let spec = spec_yaml(
101            "id: t\n\
102             kind: file_min_size\n\
103             min_bytes: 100\n\
104             level: warning\n",
105        );
106        assert!(build(&spec).is_err());
107    }
108
109    #[test]
110    fn evaluate_passes_when_size_above_minimum() {
111        let spec = spec_yaml(
112            "id: t\n\
113             kind: file_min_size\n\
114             paths: \"README.md\"\n\
115             min_bytes: 100\n\
116             level: warning\n",
117        );
118        let rule = build(&spec).unwrap();
119        let idx = idx_with_size("README.md", 1024);
120        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
121        assert!(v.is_empty());
122    }
123
124    #[test]
125    fn evaluate_fires_when_size_below_minimum() {
126        let spec = spec_yaml(
127            "id: t\n\
128             kind: file_min_size\n\
129             paths: \"README.md\"\n\
130             min_bytes: 100\n\
131             level: warning\n",
132        );
133        let rule = build(&spec).unwrap();
134        let idx = idx_with_size("README.md", 10);
135        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
136        assert_eq!(v.len(), 1);
137    }
138
139    #[test]
140    fn evaluate_size_at_exact_minimum_passes() {
141        // Boundary: `entry.size < min_bytes` is strict, so a
142        // file at exactly min_bytes passes.
143        let spec = spec_yaml(
144            "id: t\n\
145             kind: file_min_size\n\
146             paths: \"a.bin\"\n\
147             min_bytes: 100\n\
148             level: warning\n",
149        );
150        let rule = build(&spec).unwrap();
151        let idx = idx_with_size("a.bin", 100);
152        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
153        assert!(v.is_empty(), "size == min should pass: {v:?}");
154    }
155
156    #[test]
157    fn evaluate_zero_byte_file_fires_when_minimum_positive() {
158        let spec = spec_yaml(
159            "id: t\n\
160             kind: file_min_size\n\
161             paths: \"empty.txt\"\n\
162             min_bytes: 1\n\
163             level: warning\n",
164        );
165        let rule = build(&spec).unwrap();
166        let idx = idx_with_size("empty.txt", 0);
167        let v = rule.evaluate(&ctx(Path::new("/fake"), &idx)).unwrap();
168        assert_eq!(v.len(), 1);
169    }
170}
alint_rules/file_min_size.rs

alint_rules/
file_min_size.rs
