properly handle LSP position encoding (#5711)

* properly handle LSP position encoding

* add debug assertion to Transaction::change

* Apply suggestions from code review

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

---------

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>
pull/5736/head
Pascal Kuthe 2 years ago committed by GitHub
parent 8a602995fa
commit 7ebcf4e919
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

@ -203,6 +203,13 @@ pub fn line_end_char_index(slice: &RopeSlice, line: usize) -> usize {
.unwrap_or(0)
}
pub fn line_end_byte_index(slice: &RopeSlice, line: usize) -> usize {
slice.line_to_byte(line + 1)
- get_line_ending(&slice.line(line))
.map(|le| le.as_str().len())
.unwrap_or(0)
}
/// Fetches line `line_idx` from the passed rope slice, sans any line ending.
pub fn line_without_line_ending<'a>(slice: &'a RopeSlice, line_idx: usize) -> RopeSlice<'a> {
let start = slice.line_to_char(line_idx);

@ -481,6 +481,11 @@ impl Transaction {
for (from, to, tendril) in changes {
// Verify ranges are ordered and not overlapping
debug_assert!(last <= from);
// Verify ranges are correct
debug_assert!(
from <= to,
"Edit end must end before it starts (should {from} <= {to})"
);
// Retain from last "to" to current "from"
changeset.retain(from - last);

@ -104,7 +104,7 @@ impl Client {
server_tx,
request_counter: AtomicU64::new(0),
capabilities: OnceCell::new(),
offset_encoding: OffsetEncoding::Utf8,
offset_encoding: OffsetEncoding::Utf16,
config,
req_timeout,

@ -57,6 +57,7 @@ pub enum OffsetEncoding {
pub mod util {
use super::*;
use helix_core::line_ending::{line_end_byte_index, line_end_char_index};
use helix_core::{diagnostic::NumberOrString, Range, Rope, Selection, Tendril, Transaction};
/// Converts a diagnostic in the document to [`lsp::Diagnostic`].
@ -117,7 +118,7 @@ pub mod util {
/// Converts [`lsp::Position`] to a position in the document.
///
/// Returns `None` if position exceeds document length or an operation overflows.
/// Returns `None` if position.line is out of bounds or an overflow occurs
pub fn lsp_pos_to_pos(
doc: &Rope,
pos: lsp::Position,
@ -128,22 +129,58 @@ pub mod util {
return None;
}
match offset_encoding {
// We need to be careful here to fully comply ith the LSP spec.
// Two relevant quotes from the spec:
//
// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#position
// > If the character value is greater than the line length it defaults back
// > to the line length.
//
// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocuments
// > To ensure that both client and server split the string into the same
// > line representation the protocol specifies the following end-of-line sequences:
// > \n, \r\n and \r. Positions are line end character agnostic.
// > So you can not specify a position that denotes \r|\n or \n| where | represents the character offset.
//
// This means that while the line must be in bounds the `charater`
// must be capped to the end of the line.
// Note that the end of the line here is **before** the line terminator
// so we must use `line_end_char_index` istead of `doc.line_to_char(pos_line + 1)`
//
// FIXME: Helix does not fully comply with the LSP spec for line terminators.
// The LSP standard requires that line terminators are ['\n', '\r\n', '\r'].
// Without the unicode-linebreak feature disabled, the `\r` terminator is not handled by helix.
// With the unicode-linebreak feature, helix recognizes multiple extra line break chars
// which means that positions will be decoded/encoded incorrectly in their presence
let line = match offset_encoding {
OffsetEncoding::Utf8 => {
let line = doc.line_to_char(pos_line);
let pos = line.checked_add(pos.character as usize)?;
if pos <= doc.len_chars() {
Some(pos)
} else {
None
}
let line_start = doc.line_to_byte(pos_line);
let line_end = line_end_byte_index(&doc.slice(..), pos_line);
line_start..line_end
}
OffsetEncoding::Utf16 => {
let line = doc.line_to_char(pos_line);
let line_start = doc.char_to_utf16_cu(line);
let pos = line_start.checked_add(pos.character as usize)?;
doc.try_utf16_cu_to_char(pos).ok()
// TODO directly translate line index to char-idx
// ropey can do this just as easily as utf-8 byte translation
// but the functions are just missing.
// Translate to char first and then utf-16 as a workaround
let line_start = doc.line_to_char(pos_line);
let line_end = line_end_char_index(&doc.slice(..), pos_line);
doc.char_to_utf16_cu(line_start)..doc.char_to_utf16_cu(line_end)
}
};
// The LSP spec demands that the offset is capped to the end of the line
let pos = line
.start
.checked_add(pos.character as usize)
.unwrap_or(line.end)
.min(line.end);
// TODO prefer UTF32/char indices to avoid this step
match offset_encoding {
OffsetEncoding::Utf8 => doc.try_byte_to_char(pos).ok(),
OffsetEncoding::Utf16 => doc.try_utf16_cu_to_char(pos).ok(),
}
}
@ -158,8 +195,8 @@ pub mod util {
match offset_encoding {
OffsetEncoding::Utf8 => {
let line = doc.char_to_line(pos);
let line_start = doc.line_to_char(line);
let col = pos - line_start;
let line_start = doc.line_to_byte(line);
let col = doc.char_to_byte(pos) - line_start;
lsp::Position::new(line as u32, col as u32)
}
@ -606,16 +643,55 @@ mod tests {
}
test_case!("", (0, 0) => Some(0));
test_case!("", (0, 1) => None);
test_case!("", (0, 1) => Some(0));
test_case!("", (1, 0) => None);
test_case!("\n\n", (0, 0) => Some(0));
test_case!("\n\n", (1, 0) => Some(1));
test_case!("\n\n", (1, 1) => Some(2));
test_case!("\n\n", (1, 1) => Some(1));
test_case!("\n\n", (2, 0) => Some(2));
test_case!("\n\n", (3, 0) => None);
test_case!("test\n\n\n\ncase", (4, 3) => Some(11));
test_case!("test\n\n\n\ncase", (4, 4) => Some(12));
test_case!("test\n\n\n\ncase", (4, 5) => None);
test_case!("test\n\n\n\ncase", (4, 5) => Some(12));
test_case!("", (u32::MAX, u32::MAX) => None);
}
#[test]
fn emoji_format_gh_4791() {
use lsp_types::{Position, Range, TextEdit};
let edits = vec![
TextEdit {
range: Range {
start: Position {
line: 0,
character: 1,
},
end: Position {
line: 1,
character: 0,
},
},
new_text: "\n ".to_string(),
},
TextEdit {
range: Range {
start: Position {
line: 1,
character: 7,
},
end: Position {
line: 2,
character: 0,
},
},
new_text: "\n ".to_string(),
},
];
let mut source = Rope::from_str("[\n\"🇺🇸\",\n\"🎄\",\n]");
let transaction = generate_transaction_from_edits(&source, edits, OffsetEncoding::Utf8);
assert!(transaction.apply(&mut source));
}
}

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