1 //! Some infrastructure for fuzzy testing.
2 //!
3 //! We don't normally run fuzzying, so this is hopelessly bitrotten :(
4
5 use std::{
6 convert::TryInto,
7 str::{self, FromStr},
8 };
9
10 use text_edit::Indel;
11
12 use crate::{validation, AstNode, SourceFile, TextRange};
13
check_file_invariants(file: &SourceFile)14 fn check_file_invariants(file: &SourceFile) {
15 let root = file.syntax();
16 validation::validate_block_structure(root);
17 }
18
check_parser(text: &str)19 pub fn check_parser(text: &str) {
20 let file = SourceFile::parse(text);
21 check_file_invariants(&file.tree());
22 }
23
24 #[derive(Debug, Clone)]
25 pub struct CheckReparse {
26 text: String,
27 edit: Indel,
28 edited_text: String,
29 }
30
31 impl CheckReparse {
from_data(data: &[u8]) -> Option<Self>32 pub fn from_data(data: &[u8]) -> Option<Self> {
33 const PREFIX: &str = "fn main(){\n\t";
34 const SUFFIX: &str = "\n}";
35
36 let data = str::from_utf8(data).ok()?;
37 let mut lines = data.lines();
38 let delete_start = usize::from_str(lines.next()?).ok()? + PREFIX.len();
39 let delete_len = usize::from_str(lines.next()?).ok()?;
40 let insert = lines.next()?.to_string();
41 let text = lines.collect::<Vec<_>>().join("\n");
42 let text = format!("{}{}{}", PREFIX, text, SUFFIX);
43 text.get(delete_start..delete_start.checked_add(delete_len)?)?; // make sure delete is a valid range
44 let delete =
45 TextRange::at(delete_start.try_into().unwrap(), delete_len.try_into().unwrap());
46 let edited_text =
47 format!("{}{}{}", &text[..delete_start], &insert, &text[delete_start + delete_len..]);
48 let edit = Indel { insert, delete };
49 Some(CheckReparse { text, edit, edited_text })
50 }
51
run(&self)52 pub fn run(&self) {
53 let parse = SourceFile::parse(&self.text);
54 let new_parse = parse.reparse(&self.edit);
55 check_file_invariants(&new_parse.tree());
56 assert_eq!(&new_parse.tree().syntax().text().to_string(), &self.edited_text);
57 let full_reparse = SourceFile::parse(&self.edited_text);
58 for (a, b) in
59 new_parse.tree().syntax().descendants().zip(full_reparse.tree().syntax().descendants())
60 {
61 if (a.kind(), a.text_range()) != (b.kind(), b.text_range()) {
62 eprint!("original:\n{:#?}", parse.tree().syntax());
63 eprint!("reparsed:\n{:#?}", new_parse.tree().syntax());
64 eprint!("full reparse:\n{:#?}", full_reparse.tree().syntax());
65 assert_eq!(
66 format!("{:?}", a),
67 format!("{:?}", b),
68 "different syntax tree produced by the full reparse"
69 );
70 }
71 }
72 // FIXME
73 // assert_eq!(new_file.errors(), full_reparse.errors());
74 }
75 }
76