cargo-cheers 0.1.0-alpha.1

Cargo subcommand for Cheers development tooling.
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182

use crop::Rope;
use syn::{
    File, Macro, Meta,
    spanned::Spanned,
    visit::{self, Visit},
};

pub struct MaudMacro<'a> {
    pub macro_: &'a Macro,
    pub indent: Indent,
    pub macro_name: String,
}

pub struct Indent {
    pub tabs: usize,
    pub spaces: usize,
}

struct MacroVisitor<'a> {
    macros: Vec<MaudMacro<'a>>,
    source: Rope,
    macro_names: &'a Vec<String>,
    skip_count: usize,
}

impl<'ast> Visit<'ast> for MacroVisitor<'ast> {
    fn visit_macro(&mut self, node: &'ast Macro) {
        let should_format = self
            .macro_names
            .iter()
            .any(|macro_name| &get_macro_full_path(node) == macro_name);

        if should_format && self.skip_count == 0 {
            let span_line = node.span().start().line;
            let line = self.source.line(span_line - 1);

            let indent_chars: Vec<_> = line
                .chars()
                .take_while(|&c| c == ' ' || c == '\t')
                .collect();

            let tabs = indent_chars.iter().filter(|&&c| c == '\t').count();
            let spaces = indent_chars.iter().filter(|&&c| c == ' ').count();

            self.macros.push(MaudMacro {
                macro_: node,
                indent: Indent { tabs, spaces },
                macro_name: get_macro_full_path(node),
            })
        }

        // Delegate to the default impl to visit any nested functions.
        visit::visit_macro(self, node);
    }

    // attributes can occur on stmts and items - we need to make sure the stack is
    // reset when we exit this means we save the skipped length and set it back
    // to its original length
    fn visit_stmt(&mut self, i: &'ast syn::Stmt) {
        let skipped_len = self.skip_count;
        syn::visit::visit_stmt(self, i);
        self.skip_count = skipped_len;
    }

    fn visit_item(&mut self, i: &'ast syn::Item) {
        let skipped_len = self.skip_count;
        syn::visit::visit_item(self, i);
        self.skip_count = skipped_len;
    }

    fn visit_attribute(&mut self, i: &'ast syn::Attribute) {
        // we need to communicate that this stmt is skipped up the tree
        if attr_is_rustfmt_skip(i) {
            self.skip_count += 1;
        }

        syn::visit::visit_attribute(self, i);
    }
}

/// Check if an attribute is a rustfmt skip attribute
fn attr_is_rustfmt_skip(i: &syn::Attribute) -> bool {
    match &i.meta {
        Meta::Path(path) => {
            path.segments.len() == 2
                && matches!(i.style, syn::AttrStyle::Outer)
                && path.segments[0].ident == "rustfmt"
                && path.segments[1].ident == "skip"
        }
        _ => false,
    }
}

fn get_macro_full_path(mac: &Macro) -> String {
    mac.path
        .segments
        .iter()
        .map(|path| path.ident.to_string())
        .collect::<Vec<String>>()
        .join("::")
}

pub fn collect_macros_from_file<'a>(
    file: &'a File,
    source: Rope,
    macro_names: &'a Vec<String>,
) -> (Rope, Vec<MaudMacro<'a>>) {
    let mut macro_visitor = MacroVisitor {
        macros: Vec::new(),
        source,
        macro_names,
        skip_count: 0,
    };
    macro_visitor.visit_file(file);

    (macro_visitor.source, macro_visitor.macros)
}

#[cfg(test)]
mod test {
    use crate::testing::*;

    test_default!(
        rustfmt_skip,
        r#"
        #[rustfmt::skip]
        html! {
        p { }
        }
        "#,
        r#"
        #[rustfmt::skip]
        html! {
        p { }
        }
        "#
    );

    test_default!(
        rustfmt_skip_only_one,
        r#"
        html! {
        p { }
        }

        #[rustfmt::skip]
        html! {
        p { }
        }

        html! {
        p { }
        }
        "#,
        r#"
        html! {
            p {}
        }

        #[rustfmt::skip]
        html! {
        p { }
        }

        html! {
            p {}
        }
        "#
    );

    test_default!(
        rustfmt_skip_one_liner,
        r#"
        #[rustfmt::skip]
        html! {p{}}
        "#,
        r#"
        #[rustfmt::skip]
        html! {p{}}
        "#
    );
}