cha-core 0.6.2

Core analysis engine for Cha — pluggable code smell detection
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

use crate::Finding;

/// Filter out findings suppressed by `cha:ignore` comments in source code.
///
/// Supported formats:
/// - `// cha:ignore` — suppress all rules for the next function/class
/// - `// cha:ignore rule_name` — suppress specific rule
/// - `// cha:ignore rule1,rule2` — suppress multiple rules
/// - `# cha:ignore ...` — Python style
/// - `/* cha:ignore ... */` — block comment style
pub fn filter_ignored(findings: Vec<Finding>, source: &str) -> Vec<Finding> {
    let ignores = parse_ignore_comments(source);
    if ignores.is_empty() {
        return findings;
    }
    findings
        .into_iter()
        .filter(|f| !is_suppressed(f, &ignores))
        .collect()
}

struct IgnoreDirective {
    /// Line number where the comment appears (1-based).
    line: usize,
    /// Rule names to ignore. Empty = ignore all.
    rules: Vec<String>,
}

fn parse_ignore_comments(source: &str) -> Vec<IgnoreDirective> {
    source
        .lines()
        .enumerate()
        .filter_map(|(i, line)| {
            let trimmed = line.trim();
            let after = extract_ignore_payload(trimmed)?;
            let rules = if after.is_empty() {
                vec![]
            } else {
                after.split(',').map(|s| s.trim().to_string()).collect()
            };
            Some(IgnoreDirective { line: i + 1, rules })
        })
        .collect()
}

fn extract_ignore_payload(line: &str) -> Option<&str> {
    // // cha:ignore ... or # cha:ignore ... or /* cha:ignore ... */
    for prefix in ["//", "#", "--"] {
        if let Some(rest) = line.strip_prefix(prefix)
            && let Some(payload) = rest.trim().strip_prefix("cha:ignore")
        {
            return Some(payload.trim());
        }
    }
    if let Some(rest) = line.strip_prefix("/*") {
        let rest = rest.strip_suffix("*/").unwrap_or(rest);
        if let Some(payload) = rest.trim().strip_prefix("cha:ignore") {
            return Some(payload.trim());
        }
    }
    None
}

fn is_suppressed(finding: &Finding, ignores: &[IgnoreDirective]) -> bool {
    ignores.iter().any(|ig| {
        // Comment on the line before the finding's start, or on the same line
        let covers = ig.line == finding.location.start_line
            || ig.line + 1 == finding.location.start_line
            // Comment anywhere before the finding within 1 line gap
            || (ig.line < finding.location.start_line
                && ig.line + 1 >= finding.location.start_line);
        if !covers {
            return false;
        }
        ig.rules.is_empty() || ig.rules.iter().any(|r| r == &finding.smell_name)
    })
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{Location, Severity, SmellCategory};
    use std::path::PathBuf;

    fn make_finding(name: &str, start: usize) -> Finding {
        Finding {
            smell_name: name.to_string(),
            category: SmellCategory::Bloaters,
            severity: Severity::Warning,
            location: Location {
                path: PathBuf::from("test.rs"),
                start_line: start,
                end_line: start + 5,
                name: None,
            },
            message: "test".into(),
            suggested_refactorings: vec![],
        }
    }

    #[test]
    fn ignore_all_rules() {
        let src = "// cha:ignore\nfn foo() {}";
        let findings = vec![make_finding("switch_statement", 2)];
        assert!(filter_ignored(findings, src).is_empty());
    }

    #[test]
    fn ignore_specific_rule() {
        let src = "// cha:ignore switch_statement\nfn foo() {}";
        let findings = vec![
            make_finding("switch_statement", 2),
            make_finding("long_method", 2),
        ];
        let result = filter_ignored(findings, src);
        assert_eq!(result.len(), 1);
        assert_eq!(result[0].smell_name, "long_method");
    }

    #[test]
    fn ignore_multiple_rules() {
        let src = "// cha:ignore switch_statement,long_method\nfn foo() {}";
        let findings = vec![
            make_finding("switch_statement", 2),
            make_finding("long_method", 2),
        ];
        assert!(filter_ignored(findings, src).is_empty());
    }

    #[test]
    fn no_ignore_comment() {
        let src = "fn foo() {}";
        let findings = vec![make_finding("switch_statement", 1)];
        assert_eq!(filter_ignored(findings, src).len(), 1);
    }

    #[test]
    fn python_style() {
        let src = "# cha:ignore\ndef foo(): pass";
        let findings = vec![make_finding("long_method", 2)];
        assert!(filter_ignored(findings, src).is_empty());
    }
}