| //! Some infrastructure for fuzzy testing. |
| //! |
| //! We don't normally run fuzzying, so this is hopelessly bitrotten :( |
| |
| use std::str::{self, FromStr}; |
| |
| use text_edit::Indel; |
| |
| use crate::{validation, AstNode, SourceFile, TextRange}; |
| |
| fn check_file_invariants(file: &SourceFile) { |
| let root = file.syntax(); |
| validation::validate_block_structure(root); |
| } |
| |
| pub fn check_parser(text: &str) { |
| let file = SourceFile::parse(text); |
| check_file_invariants(&file.tree()); |
| } |
| |
| #[derive(Debug, Clone)] |
| pub struct CheckReparse { |
| text: String, |
| edit: Indel, |
| edited_text: String, |
| } |
| |
| impl CheckReparse { |
| pub fn from_data(data: &[u8]) -> Option<Self> { |
| const PREFIX: &str = "fn main(){\n\t"; |
| const SUFFIX: &str = "\n}"; |
| |
| let data = str::from_utf8(data).ok()?; |
| let mut lines = data.lines(); |
| let delete_start = usize::from_str(lines.next()?).ok()? + PREFIX.len(); |
| let delete_len = usize::from_str(lines.next()?).ok()?; |
| let insert = lines.next()?.to_owned(); |
| let text = lines.collect::<Vec<_>>().join("\n"); |
| let text = format!("{PREFIX}{text}{SUFFIX}"); |
| text.get(delete_start..delete_start.checked_add(delete_len)?)?; // make sure delete is a valid range |
| let delete = |
| TextRange::at(delete_start.try_into().unwrap(), delete_len.try_into().unwrap()); |
| let edited_text = |
| format!("{}{}{}", &text[..delete_start], &insert, &text[delete_start + delete_len..]); |
| let edit = Indel { insert, delete }; |
| Some(CheckReparse { text, edit, edited_text }) |
| } |
| |
| #[allow(clippy::print_stderr)] |
| pub fn run(&self) { |
| let parse = SourceFile::parse(&self.text); |
| let new_parse = parse.reparse(&self.edit); |
| check_file_invariants(&new_parse.tree()); |
| assert_eq!(&new_parse.tree().syntax().text().to_string(), &self.edited_text); |
| let full_reparse = SourceFile::parse(&self.edited_text); |
| for (a, b) in |
| new_parse.tree().syntax().descendants().zip(full_reparse.tree().syntax().descendants()) |
| { |
| if (a.kind(), a.text_range()) != (b.kind(), b.text_range()) { |
| eprint!("original:\n{:#?}", parse.tree().syntax()); |
| eprint!("reparsed:\n{:#?}", new_parse.tree().syntax()); |
| eprint!("full reparse:\n{:#?}", full_reparse.tree().syntax()); |
| assert_eq!( |
| format!("{a:?}"), |
| format!("{b:?}"), |
| "different syntax tree produced by the full reparse" |
| ); |
| } |
| } |
| // FIXME |
| // assert_eq!(new_file.errors(), full_reparse.errors()); |
| } |
| } |