rolldown_sourcemap/
lib.rs

1mod source;
2mod source_joiner;
3
4use std::sync::Arc;
5
6use oxc_sourcemap::Token;
7
8pub use oxc_sourcemap::{JSONSourceMap, SourceMap, SourceMapBuilder, SourcemapVisualizer};
9pub use source_joiner::SourceJoiner;
10
11pub use crate::source::{Source, SourceMapSource};
12
13/// Strips the first `lines` destination lines from the sourcemap, decrementing all remaining
14/// destination line numbers accordingly. Used to re-anchor a sourcemap after removing a
15/// prefix (e.g. a shebang line) from the generated code.
16pub fn adjust_sourcemap_dst_lines(sourcemap: SourceMap, lines: u32) -> SourceMap {
17  if lines == 0 {
18    return sourcemap;
19  }
20
21  let tokens: Box<[Token]> = sourcemap
22    .get_tokens()
23    .filter(|t| t.get_dst_line() >= lines)
24    .map(|token| {
25      Token::new(
26        token.get_dst_line() - lines,
27        token.get_dst_col(),
28        token.get_src_line(),
29        token.get_src_col(),
30        token.get_source_id(),
31        token.get_name_id(),
32      )
33    })
34    .collect();
35
36  SourceMap::new(
37    sourcemap.get_file().cloned(),
38    sourcemap.get_names().cloned().collect(),
39    sourcemap.get_source_root().map(str::to_owned),
40    sourcemap.get_sources().cloned().collect(),
41    sourcemap.get_source_contents().map(|c| c.map(Arc::clone)).collect(),
42    tokens,
43    None,
44  )
45}
46
47// <https://github.com/rollup/rollup/blob/master/src/utils/collapseSourcemaps.ts>
48pub fn collapse_sourcemaps(sourcemap_chain: &[&SourceMap]) -> SourceMap {
49  debug_assert!(sourcemap_chain.len() > 1);
50  if sourcemap_chain.len() == 1 {
51    // If there's only one sourcemap, return it as is.
52    return sourcemap_chain[0].clone();
53  }
54
55  let last_map = sourcemap_chain.last().expect("sourcemap_chain should not be empty");
56  let first_map = sourcemap_chain.first().expect("sourcemap_chain should not be empty");
57  let chain_without_last = &sourcemap_chain[..sourcemap_chain.len() - 1];
58
59  // Pre-compute lookup tables in reverse order so we avoid reversing on every token lookup.
60  let sourcemap_and_lookup_table: Vec<_> = chain_without_last
61    .iter()
62    .rev()
63    .map(|sourcemap| (*sourcemap, sourcemap.generate_lookup_table()))
64    .collect();
65
66  let tokens: Box<[Token]> = last_map
67    .get_source_view_tokens()
68    .filter_map(|token| {
69      let original_token =
70        sourcemap_and_lookup_table.iter().try_fold(token, |token, (sourcemap, lookup_table)| {
71          sourcemap.lookup_source_view_token(
72            lookup_table,
73            token.get_src_line(),
74            token.get_src_col(),
75          )
76        });
77      original_token.map(|original_token| {
78        Token::new(
79          token.get_dst_line(),
80          token.get_dst_col(),
81          original_token.get_src_line(),
82          original_token.get_src_col(),
83          original_token.get_source_id(),
84          original_token.get_name_id(),
85        )
86      })
87    })
88    .collect();
89
90  SourceMap::new(
91    None,
92    first_map.get_names().cloned().collect(),
93    None,
94    first_map.get_sources().cloned().collect(),
95    first_map.get_source_contents().map(|x| x.map(Arc::clone)).collect(),
96    tokens,
97    None,
98  )
99}
100
101#[test]
102fn test_collapse_sourcemaps() {
103  use crate::{SourceJoiner, SourceMapSource, collapse_sourcemaps};
104  use oxc::{
105    allocator::Allocator,
106    codegen::{Codegen, CodegenOptions, CodegenReturn, CommentOptions},
107    parser::Parser,
108    span::SourceType,
109  };
110  use oxc_sourcemap::SourcemapVisualizer;
111
112  let allocator = Allocator::default();
113
114  let mut source_joiner = SourceJoiner::default();
115
116  let filename = "foo.js".to_string();
117  let source_text = "const foo = 1; console.log(foo);\n".to_string();
118  let source_type = SourceType::from_path(&filename).unwrap();
119  let ret1 = Parser::new(&allocator, &source_text, source_type).parse();
120  let CodegenReturn { map, code, .. } = Codegen::new()
121    .with_options(CodegenOptions {
122      comments: CommentOptions { normal: false, ..CommentOptions::default() },
123      source_map_path: Some(filename.into()),
124      ..CodegenOptions::default()
125    })
126    .build(&ret1.program);
127  source_joiner.append_source(SourceMapSource::new(code, map.as_ref().unwrap().clone()));
128
129  let filename = "bar.js".to_string();
130  let source_text = "const bar = 2; console.log(bar);\n".to_string();
131  let ret2: oxc::parser::ParserReturn = Parser::new(&allocator, &source_text, source_type).parse();
132  let CodegenReturn { map, code, .. } = Codegen::new()
133    .with_options(CodegenOptions {
134      source_map_path: Some(filename.into()),
135      ..CodegenOptions::default()
136    })
137    .build(&ret2.program);
138  source_joiner.append_source(SourceMapSource::new(code, map.as_ref().unwrap().clone()));
139
140  let (source_text, source_map) = source_joiner.join();
141
142  let mut sourcemap_chain = vec![];
143
144  sourcemap_chain.push(source_map.as_ref().unwrap());
145
146  let filename = "chunk.js".to_string();
147  let ret3 = Parser::new(&allocator, &source_text, source_type).parse();
148  let CodegenReturn { map, code, .. } = Codegen::new()
149    .with_options(CodegenOptions {
150      comments: CommentOptions { normal: false, ..CommentOptions::default() },
151      source_map_path: Some(filename.into()),
152      ..CodegenOptions::default()
153    })
154    .build(&ret3.program);
155  sourcemap_chain.push(map.as_ref().unwrap());
156
157  let map = collapse_sourcemaps(&sourcemap_chain);
158  assert_eq!(
159    SourcemapVisualizer::new(&code, &map).get_text(),
160    r#"- foo.js
161(0:0) "const " --> (0:0) "const "
162(0:6) "foo = " --> (0:6) "foo = "
163(0:12) "1; " --> (0:12) "1;\n"
164(0:15) "console." --> (1:0) "console."
165(0:23) "log(" --> (1:8) "log("
166(0:27) "foo" --> (1:12) "foo"
167(0:30) ");\n" --> (1:15) ");\n"
168- bar.js
169(0:0) "const " --> (2:0) "const "
170(0:6) "bar = " --> (2:6) "bar = "
171(0:12) "2; " --> (2:12) "2;\n"
172(0:15) "console." --> (3:0) "console."
173(0:23) "log(" --> (3:8) "log("
174(0:27) "bar" --> (3:12) "bar"
175(0:30) ");\n" --> (3:15) ");\n"
176"#
177  );
178}
179
180/// Test for https://github.com/rollup/rollup/issues/5955
181#[test]
182fn test_collapse_sourcemaps_with_coarse_segments() {
183  use oxc_sourcemap::SourceMap;
184
185  fn get_loc(mut pos: usize, code: &str) -> (u32, u32) {
186    for (line_idx, line) in code.lines().enumerate() {
187      if pos <= line.len() {
188        #[expect(clippy::cast_possible_truncation)]
189        return (line_idx as u32, pos as u32);
190      }
191      pos -= line.len() + 1; // +1 for newline
192    }
193    panic!("position out of bounds");
194  }
195
196  let original_code = "import { useEffect } from 'react';
197
198export function App() {
199  useEffect(() => {
200    console.log('ReplayAnalyze');
201  }, []);
202
203  return <div>{'.'}</div>;
204}
205";
206  let transformed_code = r#"import{jsx}from"react/jsx-runtime";import{useEffect}from"react";export function App(){return useEffect((()=>{console.log("ReplayAnalyze")}),[]),jsx("div",{children:"."})}"#;
207
208  // spellchecker:off
209  let esbuild_map_json = r#"{
210    "version": 3,
211    "sources": ["<stdin>"],
212    "sourcesContent": ["import { useEffect } from 'react';\n\nexport function App() {\n  useEffect(() => {\n    console.log('ReplayAnalyze');\n  }, []);\n\n  return <div>{'.'}</div>;\n}\n"],
213    "mappings": "AAOS;AAPT,SAAS,iBAAiB;AAEnB,gBAAS,MAAM;AACpB,YAAU,MAAM;AACd,YAAQ,IAAI,eAAe;AAAA,EAC7B,GAAG,CAAC,CAAC;AAEL,SAAO,oBAAC,SAAK,eAAI;AACnB;",
214    "names": []
215  }"#;
216  // spellchecker:on
217  let esbuild_map = SourceMap::from_json_string(esbuild_map_json).unwrap();
218
219  // spellchecker:off
220  let terser_map_json = r#"{
221    "version": 3,
222    "names": ["jsx", "useEffect", "App", "console", "log", "children"],
223    "sources": ["0"],
224    "sourcesContent": ["import { jsx } from \"react/jsx-runtime\";\nimport { useEffect } from \"react\";\nexport function App() {\n  useEffect(() => {\n    console.log(\"ReplayAnalyze\");\n  }, []);\n  return /* @__PURE__ */ jsx(\"div\", { children: \".\" });\n}\n"],
225    "mappings": "OAASA,QAAW,2BACXC,cAAiB,eACnB,SAASC,MAId,OAHAD,WAAU,KACRE,QAAQC,IAAI,gBAAgB,GAC3B,IACoBJ,IAAI,MAAO,CAAEK,SAAU,KAChD"
226  }"#;
227  // spellchecker:on
228  let terser_map = SourceMap::from_json_string(terser_map_json).unwrap();
229
230  let collapsed = collapse_sourcemaps(&[&esbuild_map, &terser_map]);
231  let collapsed_lookup_table = collapsed.generate_lookup_table();
232
233  let generated_loc = get_loc(transformed_code.find("return").unwrap(), transformed_code);
234  let original_loc = collapsed
235    .lookup_source_view_token(&collapsed_lookup_table, generated_loc.0, generated_loc.1)
236    .map(|token| (token.get_src_line(), token.get_src_col()));
237  assert_eq!(
238    original_loc,
239    Some(get_loc(original_code.find("return").unwrap(), original_code)),
240    "collapsed sourcemap should map 'return' in transformed code back to original source"
241  );
242}
rolldown_sourcemap/lib.rs

rolldown_sourcemap/
lib.rs
