cpd_tokenizer/
javascript.rs

1// cpd-tokenizer: OXC-based tokenizer for JavaScript/TypeScript/JSX/TSX.
2// Dispatched for formats: javascript, typescript, jsx, tsx.
3
4use std::panic::{AssertUnwindSafe, catch_unwind};
5use std::path::Path;
6
7use oxc_allocator::Allocator;
8use oxc_parser::{Kind, Parser, config::TokensParserConfig};
9use oxc_span::SourceType;
10
11use cpd_core::models::{Token, TokenKind};
12
13use crate::line_index::LineIndex;
14
15// ── fallback tokenizer ────────────────────────────────────────────────────────
16
17mod fallback {
18    use super::LineIndex;
19    use cpd_core::models::{Token, TokenKind};
20
21    fn find_ignore_ranges(source: &str) -> Vec<[usize; 2]> {
22        let mut ranges = Vec::new();
23        let mut start: Option<usize> = None;
24        let bytes = source.as_bytes();
25        let mut i = 0;
26        while i < bytes.len() {
27            if i + 1 < bytes.len() && bytes[i] == b'/' {
28                let end = if bytes[i + 1] == b'/' {
29                    bytes[i..]
30                        .iter()
31                        .position(|&b| b == b'\n')
32                        .map(|p| i + p)
33                        .unwrap_or(bytes.len())
34                } else if bytes[i + 1] == b'*' {
35                    bytes[i..]
36                        .windows(2)
37                        .position(|w| w == b"*/")
38                        .map(|p| i + p + 2)
39                        .unwrap_or(bytes.len())
40                } else {
41                    i += 1;
42                    continue;
43                };
44                let comment_text = &source[i..end];
45                if comment_text.contains("jscpd:ignore-start") {
46                    start = Some(end);
47                } else if comment_text.contains("jscpd:ignore-end") {
48                    if let Some(s) = start.take() {
49                        ranges.push([s, i]);
50                    }
51                }
52                i = end;
53                continue;
54            }
55            i += 1;
56        }
57        ranges
58    }
59
60    fn in_ignore(offset: usize, end: usize, ranges: &[[usize; 2]]) -> bool {
61        ranges.iter().any(|[rs, re]| offset < *re && end > *rs)
62    }
63
64    /// Simple word-split fallback tokenizer. Never panics.
65    pub fn tokenize(source: &str, _format: &str) -> Vec<Token> {
66        let ignore_ranges = find_ignore_ranges(source);
67        let bytes = source.as_bytes();
68        let line_index = LineIndex::new(bytes);
69        let mut tokens = Vec::new();
70        let mut i = 0;
71        while i < bytes.len() {
72            let ch = match source[i..].chars().next() {
73                Some(c) => c,
74                None => break,
75            };
76            if ch.is_whitespace() {
77                i += ch.len_utf8();
78                continue;
79            }
80            if ch.is_alphanumeric() || ch == '_' || ch == '$' {
81                let start = i;
82                while i < bytes.len() {
83                    let c = source[i..].chars().next().unwrap_or('\0');
84                    if c.is_alphanumeric() || c == '_' || c == '$' {
85                        i += c.len_utf8();
86                    } else {
87                        break;
88                    }
89                }
90                let kind = if in_ignore(start, i, &ignore_ranges) {
91                    TokenKind::Ignore
92                } else {
93                    TokenKind::Other
94                };
95                tokens.push(Token {
96                    kind,
97                    value: source[start..i].to_string(),
98                    start: line_index.location(start),
99                    end: line_index.location(i),
100                });
101            } else {
102                let start = i;
103                i += ch.len_utf8();
104                let kind = if in_ignore(start, i, &ignore_ranges) {
105                    TokenKind::Ignore
106                } else {
107                    TokenKind::Other
108                };
109                tokens.push(Token {
110                    kind,
111                    value: ch.to_string(),
112                    start: line_index.location(start),
113                    end: line_index.location(i),
114                });
115            }
116        }
117        tokens
118    }
119}
120
121// ── helpers ──────────────────────────────────────────────────────────────────
122
123fn find_ignore_ranges(source: &str) -> Vec<[usize; 2]> {
124    let mut ranges = Vec::new();
125    let mut start: Option<usize> = None;
126    let bytes = source.as_bytes();
127    let mut i = 0;
128    while i < bytes.len() {
129        if i + 1 < bytes.len() && bytes[i] == b'/' {
130            let end = if bytes[i + 1] == b'/' {
131                bytes[i..]
132                    .iter()
133                    .position(|&b| b == b'\n')
134                    .map(|p| i + p)
135                    .unwrap_or(bytes.len())
136            } else if bytes[i + 1] == b'*' {
137                bytes[i..]
138                    .windows(2)
139                    .position(|w| w == b"*/")
140                    .map(|p| i + p + 2)
141                    .unwrap_or(bytes.len())
142            } else {
143                i += 1;
144                continue;
145            };
146            let comment_text = &source[i..end];
147            if comment_text.contains("jscpd:ignore-start") {
148                start = Some(end);
149            } else if comment_text.contains("jscpd:ignore-end") {
150                if let Some(s) = start.take() {
151                    ranges.push([s, i]);
152                }
153            }
154            i = end;
155            continue;
156        }
157        i += 1;
158    }
159    ranges
160}
161
162fn in_ignore(offset: usize, end: usize, ranges: &[[usize; 2]]) -> bool {
163    ranges.iter().any(|[rs, re]| offset < *re && end > *rs)
164}
165
166const fn map_kind(kind: Kind) -> TokenKind {
167    if matches!(kind, Kind::Ident) {
168        return TokenKind::Identifier;
169    }
170    if kind.is_any_keyword() {
171        return TokenKind::Keyword;
172    }
173    if kind.is_literal() {
174        return TokenKind::Literal;
175    }
176    if kind.is_assignment_operator() {
177        return TokenKind::Operator;
178    }
179    if kind.is_binary_operator()
180        || kind.is_logical_operator()
181        || kind.is_unary_operator()
182        || kind.is_update_operator()
183    {
184        return TokenKind::Operator;
185    }
186    match kind {
187        Kind::Arrow => TokenKind::Operator,
188        Kind::Semicolon
189        | Kind::Comma
190        | Kind::Dot
191        | Kind::Dot3
192        | Kind::Colon
193        | Kind::LParen
194        | Kind::RParen
195        | Kind::LCurly
196        | Kind::RCurly
197        | Kind::LBrack
198        | Kind::RBrack
199        | Kind::At => TokenKind::Punctuation,
200        Kind::QuestionDot => TokenKind::Punctuation,
201        _ => TokenKind::Other,
202    }
203}
204
205fn source_type_for_format(format: &str) -> SourceType {
206    let filename = match format {
207        "typescript" => "input.ts",
208        "tsx" => "input.tsx",
209        _ => "input.jsx", // javascript + jsx both use jsx
210    };
211    SourceType::from_path(Path::new(filename)).unwrap_or_default()
212}
213
214// ── public API ───────────────────────────────────────────────────────────────
215
216/// Tokenize JS/TS/JSX/TSX source. Never panics.
217pub fn tokenize_js(source: &str, format: &str) -> Vec<Token> {
218    if source.is_empty() {
219        return Vec::new();
220    }
221
222    match catch_unwind(AssertUnwindSafe(|| parse_with_oxc(source, format))) {
223        Ok(Some(tokens)) => tokens,
224        Ok(None) => {
225            log::debug!("cpd-tokenizer: OXC parse errors in {format} source, using fallback");
226            fallback::tokenize(source, format)
227        }
228        Err(_) => {
229            log::debug!("cpd-tokenizer: OXC panicked on {format} source, using fallback");
230            fallback::tokenize(source, format)
231        }
232    }
233}
234
235fn parse_with_oxc(source: &str, format: &str) -> Option<Vec<Token>> {
236    let allocator = Allocator::new();
237    let source_type = source_type_for_format(format);
238
239    let parser_return = Parser::new(&allocator, source, source_type)
240        .with_config(TokensParserConfig)
241        .parse();
242
243    if !parser_return.errors.is_empty() {
244        return None;
245    }
246
247    let ignore_ranges = find_ignore_ranges(source);
248    let bytes = source.as_bytes();
249    // Build LineIndex once — O(n) — then all location calls are O(log n).
250    let line_index = LineIndex::new(bytes);
251
252    let tokens = parser_return.tokens
253        .into_iter()
254        .filter_map(|token| {
255            let start = (token.start() as usize).min(source.len());
256            let end = (token.end() as usize).min(source.len());
257            if start >= end {
258                return None;
259            }
260            let kind = token.kind();
261            if matches!(kind, Kind::Eof | Kind::Undetermined | Kind::Skip) {
262                return None;
263            }
264            let value = &source[start..end];
265            let token_kind = if in_ignore(start, end, &ignore_ranges) {
266                TokenKind::Ignore
267            } else {
268                map_kind(kind)
269            };
270
271            Some(Token {
272                kind: token_kind,
273                value: value.to_string(),
274                start: line_index.location(start),
275                end: line_index.location(end),
276            })
277        })
278        .collect::<Vec<Token>>();
279
280    Some(tokens)
281}
282
283// ── tests ─────────────────────────────────────────────────────────────────────
284#[cfg(test)]
285mod tests {
286    use super::*;
287
288    #[test]
289    fn valid_js_produces_tokens() {
290        let tokens = tokenize_js("function hello() { return 42; }", "javascript");
291        assert!(!tokens.is_empty(), "valid JS must produce tokens");
292    }
293
294    #[test]
295    fn typescript_produces_tokens() {
296        let tokens = tokenize_js("const x: number = 5;", "typescript");
297        assert!(!tokens.is_empty());
298    }
299
300    #[test]
301    fn malformed_js_does_not_panic() {
302        let result = std::panic::catch_unwind(|| tokenize_js("let x = {{{", "javascript"));
303        assert!(result.is_ok(), "malformed JS must not panic");
304    }
305
306    #[test]
307    fn empty_source_returns_empty() {
308        let tokens = tokenize_js("", "javascript");
309        drop(tokens);
310    }
311
312    #[test]
313    fn ignore_region_tokens_marked_as_ignore() {
314        let source = r#"
315const a = 1;
316// jscpd:ignore-start
317const b = 2;
318// jscpd:ignore-end
319const c = 3;
320"#;
321        let tokens = tokenize_js(source, "javascript");
322        let has_ignore = tokens
323            .iter()
324            .any(|t| t.kind == cpd_core::models::TokenKind::Ignore);
325        assert!(has_ignore, "tokens in ignore region must be marked Ignore");
326    }
327
328    #[test]
329    fn jsx_produces_tokens() {
330        let tokens = tokenize_js("const el = <div>hello</div>;", "jsx");
331        assert!(!tokens.is_empty());
332    }
333
334    #[test]
335    fn tsx_with_type_annotation() {
336        let tokens = tokenize_js("const fn = (x: React.FC): void => {};", "tsx");
337        assert!(!tokens.is_empty());
338    }
339
340    #[test]
341    fn multiline_location_uses_binary_search() {
342        let source = "const a = 1;\nconst b = 2;\nconst c = 3;";
343        let tokens = tokenize_js(source, "javascript");
344        // "b" is on line 2
345        let b_token = tokens.iter().find(|t| t.value == "b");
346        assert!(b_token.is_some(), "must find token b");
347        assert_eq!(b_token.unwrap().start.line, 2, "b must be on line 2");
348    }
349}
cpd_tokenizer/javascript.rs

cpd_tokenizer/
javascript.rs
