rrubocop 0.8.15

10x faster RuboCop drop-in. Same output format and configs, without maintaining RuboCop gems.
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
144

use tree_sitter::Node;

use crate::cop::shared::{argument_nodes, call_method_name, call_receiver};
use crate::cop::{Cop, CopConfig};
use crate::correction::Correction;
use crate::diagnostic::{Diagnostic, Severity};
use crate::parse::source::SourceFile;

/// Lint/DeprecatedClassMethods — iterator?, attr with bool, etc.
pub struct DeprecatedClassMethods;

fn replace_method(
    cop: &DeprecatedClassMethods,
    source: &SourceFile,
    node: Node<'_>,
    msg: String,
    replacement: &str,
    diagnostics: &mut Vec<Diagnostic>,
    corrections: &mut Option<&mut Vec<Correction>>,
) {
    let meth = node.child_by_field_name("method").unwrap_or(node);
    let (line, col) = source.offset_to_line_col(meth.start_byte());
    let mut diag = cop.diagnostic(source, line, col, msg);
    if let Some(corr) = corrections.as_mut() {
        corr.push(Correction {
            start: meth.start_byte(),
            end: meth.end_byte(),
            replacement: replacement.to_string(),
            cop_name: cop.name(),
            cop_index: 0,
        });
        diag.corrected = true;
    }
    diagnostics.push(diag);
}

fn check_iterator(
    cop: &DeprecatedClassMethods,
    source: &SourceFile,
    node: Node<'_>,
    diagnostics: &mut Vec<Diagnostic>,
    corrections: &mut Option<&mut Vec<Correction>>,
) -> bool {
    if call_method_name(source, node) != Some(b"iterator?") {
        return false;
    }
    replace_method(
        cop,
        source,
        node,
        "`iterator?` is deprecated in favor of `block_given?`.".to_string(),
        "block_given?",
        diagnostics,
        corrections,
    );
    true
}

fn attr_prefer(args: &[Node<'_>]) -> Option<&'static str> {
    if args.len() != 2 || !matches!(args[1].kind(), "true" | "false") {
        return None;
    }
    Some(if args[1].kind() == "true" {
        "attr_accessor"
    } else {
        "attr_reader"
    })
}

fn drop_bool_arg(node: Node<'_>, args: &[Node<'_>], cop_name: &'static str) -> Correction {
    let mut cur = node.walk();
    Correction {
        start: args[0].end_byte(),
        end: node
            .children(&mut cur)
            .find(|c| !c.is_named() && c.kind() == ")")
            .map(|c| c.start_byte())
            .unwrap_or(node.end_byte()),
        replacement: String::new(),
        cop_name,
        cop_index: 0,
    }
}

fn check_attr(
    cop: &DeprecatedClassMethods,
    source: &SourceFile,
    node: Node<'_>,
    diagnostics: &mut Vec<Diagnostic>,
    corrections: &mut Option<&mut Vec<Correction>>,
) {
    if call_method_name(source, node) != Some(b"attr") || call_receiver(node).is_some() {
        return;
    }
    let args = argument_nodes(node);
    let Some(prefer) = attr_prefer(&args) else {
        return;
    };
    replace_method(
        cop,
        source,
        node,
        format!("`attr` is deprecated in favor of `{prefer}`."),
        prefer,
        diagnostics,
        corrections,
    );
    if let Some(corr) = corrections.as_mut() {
        // replace_method already marked corrected; also drop bool arg
        corr.push(drop_bool_arg(node, &args, cop.name()));
    }
}

impl Cop for DeprecatedClassMethods {
    fn name(&self) -> &'static str {
        "Lint/DeprecatedClassMethods"
    }

    fn default_severity(&self) -> Severity {
        Severity::Warning
    }

    fn supports_autocorrect(&self) -> bool {
        true
    }

    fn interested_node_kinds(&self) -> &'static [&'static str] {
        &["call"]
    }

    fn check_node(
        &self,
        source: &SourceFile,
        node: Node<'_>,
        _config: &CopConfig,
        diagnostics: &mut Vec<Diagnostic>,
        mut corrections: Option<&mut Vec<Correction>>,
    ) {
        if check_iterator(self, source, node, diagnostics, &mut corrections) {
            return;
        }
        check_attr(self, source, node, diagnostics, &mut corrections);
    }
}