forge_doc/parser/
comment.rs

1use alloy_primitives::map::HashMap;
2use derive_more::{Deref, DerefMut, derive::Display};
3use solang_parser::doccomment::DocCommentTag;
4
5/// The natspec comment tag explaining the purpose of the comment.
6/// See: <https://docs.soliditylang.org/en/v0.8.17/natspec-format.html#tags>.
7#[derive(Clone, Debug, Display, PartialEq, Eq)]
8pub enum CommentTag {
9    /// A title that should describe the contract/interface
10    Title,
11    /// The name of the author
12    Author,
13    /// Explain to an end user what this does
14    Notice,
15    /// Explain to a developer any extra details
16    Dev,
17    /// Documents a parameter just like in Doxygen (must be followed by parameter name)
18    Param,
19    /// Documents the return variables of a contract’s function
20    Return,
21    /// Copies all missing tags from the base function (must be followed by the contract name)
22    Inheritdoc,
23    /// Custom tag, semantics is application-defined
24    Custom(String),
25}
26
27impl CommentTag {
28    fn from_str(s: &str) -> Option<Self> {
29        let trimmed = s.trim();
30        let tag = match trimmed {
31            "title" => Self::Title,
32            "author" => Self::Author,
33            "notice" => Self::Notice,
34            "dev" => Self::Dev,
35            "param" => Self::Param,
36            "return" => Self::Return,
37            "inheritdoc" => Self::Inheritdoc,
38            _ if trimmed.starts_with("custom:") => {
39                // `@custom:param` tag will be parsed as `CommentTag::Param` due to a limitation
40                // on specifying parameter docs for unnamed function arguments.
41                let custom_tag = trimmed.trim_start_matches("custom:").trim();
42                match custom_tag {
43                    "param" => Self::Param,
44                    _ => Self::Custom(custom_tag.to_owned()),
45                }
46            }
47            _ => {
48                warn!(target: "forge::doc", tag=trimmed, "unknown comment tag. custom tags must be preceded by `custom:`");
49                return None;
50            }
51        };
52        Some(tag)
53    }
54}
55
56/// The natspec documentation comment.
57///
58/// Ref: <https://docs.soliditylang.org/en/v0.8.17/natspec-format.html>
59#[derive(Clone, Debug, PartialEq, Eq)]
60pub struct Comment {
61    /// The doc comment tag.
62    pub tag: CommentTag,
63    /// The doc comment value.
64    pub value: String,
65}
66
67impl Comment {
68    /// Create new instance of [Comment].
69    pub fn new(tag: CommentTag, value: String) -> Self {
70        Self { tag, value }
71    }
72
73    /// Create new instance of [Comment] from [DocCommentTag]
74    /// if it has a valid natspec tag.
75    pub fn from_doc_comment(value: DocCommentTag) -> Option<Self> {
76        CommentTag::from_str(&value.tag).map(|tag| Self { tag, value: value.value })
77    }
78
79    /// Split the comment at first word.
80    /// Useful for [CommentTag::Param] and [CommentTag::Return] comments.
81    pub fn split_first_word(&self) -> Option<(&str, &str)> {
82        self.value.trim_start().split_once(' ')
83    }
84
85    /// Match the first word of the comment with the expected.
86    /// Returns [None] if the word doesn't match.
87    /// Useful for [CommentTag::Param] and [CommentTag::Return] comments.
88    pub fn match_first_word(&self, expected: &str) -> Option<&str> {
89        self.split_first_word().and_then(
90            |(word, rest)| {
91                if word == expected { Some(rest) } else { None }
92            },
93        )
94    }
95
96    /// Check if this comment is a custom tag.
97    pub fn is_custom(&self) -> bool {
98        matches!(self.tag, CommentTag::Custom(_))
99    }
100}
101
102/// The collection of natspec [Comment] items.
103#[derive(Clone, Debug, Default, PartialEq, Deref, DerefMut)]
104pub struct Comments(Vec<Comment>);
105
106/// Forward the [Comments] function implementation to the [CommentsRef]
107/// reference type.
108macro_rules! ref_fn {
109    ($vis:vis fn $name:ident(&self$(, )?$($arg_name:ident: $arg:ty),*) -> $ret:ty) => {
110        /// Forward the function implementation to [CommentsRef] reference type.
111        $vis fn $name(&self, $($arg_name: $arg),*) -> $ret {
112            CommentsRef::from(self).$name($($arg_name),*)
113        }
114    };
115}
116
117impl Comments {
118    ref_fn!(pub fn include_tag(&self, tag: CommentTag) -> CommentsRef<'_>);
119    ref_fn!(pub fn include_tags(&self, tags: &[CommentTag]) -> CommentsRef<'_>);
120    ref_fn!(pub fn exclude_tags(&self, tags: &[CommentTag]) -> CommentsRef<'_>);
121    ref_fn!(pub fn contains_tag(&self, tag: &Comment) -> bool);
122    ref_fn!(pub fn find_inheritdoc_base(&self) -> Option<&'_ str>);
123
124    /// Attempt to lookup
125    ///
126    /// Merges two comments collections by inserting [CommentTag] from the second collection
127    /// into the first unless they are present.
128    pub fn merge_inheritdoc(
129        &self,
130        ident: &str,
131        inheritdocs: Option<HashMap<String, Self>>,
132    ) -> Self {
133        let mut result = Self(Vec::from_iter(self.iter().cloned()));
134
135        if let (Some(inheritdocs), Some(base)) = (inheritdocs, self.find_inheritdoc_base()) {
136            let key = format!("{base}.{ident}");
137            if let Some(other) = inheritdocs.get(&key) {
138                for comment in other.iter() {
139                    if !result.contains_tag(comment) {
140                        result.push(comment.clone());
141                    }
142                }
143            }
144        }
145
146        result
147    }
148}
149
150impl From<Vec<DocCommentTag>> for Comments {
151    fn from(value: Vec<DocCommentTag>) -> Self {
152        Self(value.into_iter().flat_map(Comment::from_doc_comment).collect())
153    }
154}
155
156/// The collection of references to natspec [Comment] items.
157#[derive(Debug, Default, PartialEq, Deref)]
158pub struct CommentsRef<'a>(Vec<&'a Comment>);
159
160impl<'a> CommentsRef<'a> {
161    /// Filter a collection of comments and return only those that match a provided tag.
162    pub fn include_tag(&self, tag: CommentTag) -> Self {
163        self.include_tags(&[tag])
164    }
165
166    /// Filter a collection of comments and return only those that match provided tags.
167    pub fn include_tags(&self, tags: &[CommentTag]) -> Self {
168        // Cloning only references here
169        CommentsRef(self.iter().copied().filter(|c| tags.contains(&c.tag)).collect())
170    }
171
172    /// Filter a collection of comments and return only those that do not match provided tags.
173    pub fn exclude_tags(&self, tags: &[CommentTag]) -> Self {
174        // Cloning only references here
175        CommentsRef(self.iter().copied().filter(|c| !tags.contains(&c.tag)).collect())
176    }
177
178    /// Check if the collection contains a target comment.
179    pub fn contains_tag(&self, target: &Comment) -> bool {
180        self.iter().any(|c| match (&c.tag, &target.tag) {
181            (CommentTag::Inheritdoc, CommentTag::Inheritdoc) => c.value == target.value,
182            (CommentTag::Param, CommentTag::Param) | (CommentTag::Return, CommentTag::Return) => {
183                c.split_first_word().map(|(name, _)| name)
184                    == target.split_first_word().map(|(name, _)| name)
185            }
186            (tag1, tag2) => tag1 == tag2,
187        })
188    }
189
190    /// Find an [CommentTag::Inheritdoc] comment and extract the base.
191    fn find_inheritdoc_base(&self) -> Option<&'a str> {
192        self.iter()
193            .find(|c| matches!(c.tag, CommentTag::Inheritdoc))
194            .and_then(|c| c.value.split_whitespace().next())
195    }
196
197    /// Filter a collection of comments and only return the custom tags.
198    pub fn get_custom_tags(&self) -> Self {
199        CommentsRef(self.iter().copied().filter(|c| c.is_custom()).collect())
200    }
201}
202
203impl<'a> From<&'a Comments> for CommentsRef<'a> {
204    fn from(value: &'a Comments) -> Self {
205        Self(value.iter().collect())
206    }
207}
208
209#[cfg(test)]
210mod tests {
211    use super::*;
212
213    #[test]
214    fn parse_comment_tag() {
215        assert_eq!(CommentTag::from_str("title"), Some(CommentTag::Title));
216        assert_eq!(CommentTag::from_str(" title  "), Some(CommentTag::Title));
217        assert_eq!(CommentTag::from_str("author"), Some(CommentTag::Author));
218        assert_eq!(CommentTag::from_str("notice"), Some(CommentTag::Notice));
219        assert_eq!(CommentTag::from_str("dev"), Some(CommentTag::Dev));
220        assert_eq!(CommentTag::from_str("param"), Some(CommentTag::Param));
221        assert_eq!(CommentTag::from_str("return"), Some(CommentTag::Return));
222        assert_eq!(CommentTag::from_str("inheritdoc"), Some(CommentTag::Inheritdoc));
223        assert_eq!(CommentTag::from_str("custom:"), Some(CommentTag::Custom(String::new())));
224        assert_eq!(
225            CommentTag::from_str("custom:some"),
226            Some(CommentTag::Custom("some".to_owned()))
227        );
228        assert_eq!(
229            CommentTag::from_str("  custom:   some   "),
230            Some(CommentTag::Custom("some".to_owned()))
231        );
232
233        assert_eq!(CommentTag::from_str(""), None);
234        assert_eq!(CommentTag::from_str("custom"), None);
235        assert_eq!(CommentTag::from_str("sometag"), None);
236    }
237
238    #[test]
239    fn test_is_custom() {
240        // Test custom tag.
241        let custom_comment = Comment::new(
242            CommentTag::from_str("custom:test").unwrap(),
243            "dummy custom tag".to_owned(),
244        );
245        assert!(custom_comment.is_custom(), "Custom tag should return true for is_custom");
246
247        // Test non-custom tags.
248        let non_custom_tags = [
249            CommentTag::Title,
250            CommentTag::Author,
251            CommentTag::Notice,
252            CommentTag::Dev,
253            CommentTag::Param,
254            CommentTag::Return,
255            CommentTag::Inheritdoc,
256        ];
257        for tag in non_custom_tags {
258            let comment = Comment::new(tag.clone(), "Non-custom comment".to_string());
259            assert!(
260                !comment.is_custom(),
261                "Non-custom tag {tag:?} should return false for is_custom"
262            );
263        }
264    }
265}