alint_rules/
file_ends_with.rs

1//! `file_ends_with` — every file in scope must end with the
2//! configured suffix (byte-level).
3//!
4//! Useful for required trailing banners ("<!-- end-of-file -->"),
5//! closing magic bytes, or enforcing a generated-file sentinel.
6//! For the narrower "file must end with a newline" check, prefer
7//! `final_newline` — it has a dedicated fixer and integrates with
8//! the text-hygiene family.
9//!
10//! Check-only: the correct fix is `file_append` with matching
11//! content. Auto-appending implicitly could silently duplicate a
12//! near-matching tail.
13
14use alint_core::{Context, Error, Level, Result, Rule, RuleSpec, Scope, Violation};
15use serde::Deserialize;
16
17#[derive(Debug, Deserialize)]
18#[serde(deny_unknown_fields)]
19struct Options {
20    /// The required suffix. Matched byte-for-byte.
21    suffix: String,
22}
23
24#[derive(Debug)]
25pub struct FileEndsWithRule {
26    id: String,
27    level: Level,
28    policy_url: Option<String>,
29    message: Option<String>,
30    scope: Scope,
31    suffix: Vec<u8>,
32}
33
34impl Rule for FileEndsWithRule {
35    fn id(&self) -> &str {
36        &self.id
37    }
38    fn level(&self) -> Level {
39        self.level
40    }
41    fn policy_url(&self) -> Option<&str> {
42        self.policy_url.as_deref()
43    }
44
45    fn evaluate(&self, ctx: &Context<'_>) -> Result<Vec<Violation>> {
46        let mut violations = Vec::new();
47        for entry in ctx.index.files() {
48            if !self.scope.matches(&entry.path) {
49                continue;
50            }
51            let full = ctx.root.join(&entry.path);
52            let Ok(bytes) = std::fs::read(&full) else {
53                continue;
54            };
55            if !bytes.ends_with(&self.suffix) {
56                let msg = self
57                    .message
58                    .clone()
59                    .unwrap_or_else(|| "file does not end with the required suffix".to_string());
60                violations.push(Violation::new(msg).with_path(&entry.path));
61            }
62        }
63        Ok(violations)
64    }
65}
66
67pub fn build(spec: &RuleSpec) -> Result<Box<dyn Rule>> {
68    let paths = spec
69        .paths
70        .as_ref()
71        .ok_or_else(|| Error::rule_config(&spec.id, "file_ends_with requires a `paths` field"))?;
72    let opts: Options = spec
73        .deserialize_options()
74        .map_err(|e| Error::rule_config(&spec.id, format!("invalid options: {e}")))?;
75    if opts.suffix.is_empty() {
76        return Err(Error::rule_config(
77            &spec.id,
78            "file_ends_with.suffix must not be empty",
79        ));
80    }
81    if spec.fix.is_some() {
82        return Err(Error::rule_config(
83            &spec.id,
84            "file_ends_with has no fix op — pair with an explicit `file_append` rule if you \
85             want auto-append (avoids silently duplicating near-matching suffixes).",
86        ));
87    }
88    Ok(Box::new(FileEndsWithRule {
89        id: spec.id.clone(),
90        level: spec.level,
91        policy_url: spec.policy_url.clone(),
92        message: spec.message.clone(),
93        scope: Scope::from_paths_spec(paths)?,
94        suffix: opts.suffix.into_bytes(),
95    }))
96}
alint_rules/file_ends_with.rs

alint_rules/
file_ends_with.rs
