nu-lint 1.3.0

Linter for Nu shell scripts that helpfully suggests improvements
Documentation 
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

use std::cmp::Ordering;

use nu_protocol::{
    BlockId, Span,
    ast::{Call, Expr},
};

use crate::{
    ast::{call::CallExt, expression::ExpressionExt},
    context::LintContext,
    span::FileSpan,
};

#[derive(Debug, Clone)]
pub struct CustomCommandDef {
    pub body: BlockId,
    pub name: String,
    pub name_span: Span,
    pub signature_span: Span,
    pub export_span: Option<Span>,
    pub signature: nu_protocol::Signature,
    /// Span of the entire definition (from `def`/`export def` to closing `}`)
    pub definition_span: Span,
    /// Span of the body expression (the block argument)
    pub body_expr_span: Span,
}

impl PartialEq for CustomCommandDef {
    fn eq(&self, other: &Self) -> bool {
        self.body == other.body
    }
}

impl Eq for CustomCommandDef {}

impl PartialOrd for CustomCommandDef {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for CustomCommandDef {
    fn cmp(&self, other: &Self) -> Ordering {
        self.body.cmp(&other.body)
    }
}

impl CustomCommandDef {
    pub fn try_from_call(call: &Call, context: &LintContext) -> Option<Self> {
        let decl_name = call.get_call_name(context);

        let is_exported = match decl_name.as_str() {
            "export def" => true,
            "def" => false,
            _ => return None,
        };

        let name_arg = call.get_first_positional_arg()?;
        let name = match &name_arg.expr {
            Expr::String(s) | Expr::RawString(s) => s.clone(),
            _ => context.expr_text(name_arg).to_string(),
        };

        let signature_expr = call.get_positional_arg(1)?;
        let signature_span = signature_expr.span;

        let body_expr = call.get_positional_arg(2)?;
        let block_id = body_expr.extract_block_id()?;

        let block = context.working_set.get_block(block_id);
        let signature = (*block.signature).clone();

        let export_span = is_exported.then(|| Span::new(call.head.start, call.head.start + 7));

        // The definition span is the span of the entire call expression
        let definition_span = call.span();

        Some(Self {
            body: block_id,
            name,
            name_span: name_arg.span,
            signature_span,
            export_span,
            signature,
            definition_span,
            body_expr_span: body_expr.span,
        })
    }

    pub fn is_main(&self) -> bool {
        self.name == "main" || self.name.starts_with("main ")
    }

    pub const fn is_exported(&self) -> bool {
        self.export_span.is_some()
    }

    /// Get the declaration span as a `FileSpan` for use in detections
    /// This requires the `LintContext` to normalize the global span to
    /// file-relative positions
    pub const fn declaration_span(&self, context: &LintContext) -> FileSpan {
        context.normalize_span(self.name_span)
    }
}

#[cfg(test)]
mod tests {
    use crate::context::LintContext;

    #[test]
    fn test_custom_command_spans() {
        let code = r#"
def get_first [] {
    $in | first
}

def main [] {
    [1 2 3] | get_first
}
"#;
        LintContext::test_with_parsed_source(code, |context| {
            let commands = context.custom_commands();
            assert_eq!(commands.len(), 2);

            // Verify the get_first command has correct spans
            let get_first = commands.iter().find(|c| c.name == "get_first").unwrap();
            assert!(
                context
                    .span_text(get_first.definition_span)
                    .starts_with("def get_first")
            );
            assert!(
                context
                    .span_text(get_first.body_expr_span)
                    .contains("$in | first")
            );
        });
    }
}