1 //! Generate minimal `TextEdit`s from different text versions
2 use dissimilar::Chunk;
3 use ide::{TextEdit, TextRange, TextSize};
4
diff(left: &str, right: &str) -> TextEdit5 pub(crate) fn diff(left: &str, right: &str) -> TextEdit {
6 let chunks = dissimilar::diff(left, right);
7 textedit_from_chunks(chunks)
8 }
9
textedit_from_chunks(chunks: Vec<dissimilar::Chunk>) -> TextEdit10 fn textedit_from_chunks(chunks: Vec<dissimilar::Chunk>) -> TextEdit {
11 let mut builder = TextEdit::builder();
12 let mut pos = TextSize::default();
13
14 let mut chunks = chunks.into_iter().peekable();
15 while let Some(chunk) = chunks.next() {
16 if let (Chunk::Delete(deleted), Some(&Chunk::Insert(inserted))) = (chunk, chunks.peek()) {
17 chunks.next().unwrap();
18 let deleted_len = TextSize::of(deleted);
19 builder.replace(TextRange::at(pos, deleted_len), inserted.into());
20 pos += deleted_len;
21 continue;
22 }
23
24 match chunk {
25 Chunk::Equal(text) => {
26 pos += TextSize::of(text);
27 }
28 Chunk::Delete(deleted) => {
29 let deleted_len = TextSize::of(deleted);
30 builder.delete(TextRange::at(pos, deleted_len));
31 pos += deleted_len;
32 }
33 Chunk::Insert(inserted) => {
34 builder.insert(pos, inserted.into());
35 }
36 }
37 }
38 builder.finish()
39 }
40
41 #[cfg(test)]
42 mod tests {
43 use super::*;
44
45 #[test]
diff_applies()46 fn diff_applies() {
47 let mut original = String::from("fn foo(a:u32){\n}");
48 let result = "fn foo(a: u32) {}";
49 let edit = diff(&original, result);
50 edit.apply(&mut original);
51 assert_eq!(original, result);
52 }
53 }
54