astral-sh/ruff · error · Error

Invalid value `0` for `position.line`. The line index is 1-i

Error message

Invalid value `0` for `position.line`. The line index is 1-indexed.

What it means

A wasm-bindgen Error from Position::to_text_size: the caller passed 0 for position.line. The wasm API mirrors 1-based editor coordinates (via OneIndexed), so line 0 is out of range and cannot be converted to an offset.

Source

Thrown at crates/ty_wasm/src/lib.rs:1183

#[wasm_bindgen]
impl Position {
    #[wasm_bindgen(constructor)]
    pub fn new(line: usize, column: usize) -> Self {
        Self { line, column }
    }
}

impl Position {
    fn to_text_size(
        self,
        text: &str,
        index: &LineIndex,
        position_encoding: PositionEncoding,
    ) -> Result<TextSize, Error> {
        let text_size = index.offset(
            SourceLocation {
                line: OneIndexed::new(self.line).ok_or_else(|| {
                    Error::new(
                        "Invalid value `0` for `position.line`. The line index is 1-indexed.",
                    )
                })?,
                character_offset: OneIndexed::new(self.column).ok_or_else(|| {
                    Error::new(
                        "Invalid value `0` for `position.column`. The column index is 1-indexed.",
                    )
                })?,
            },
            text,
            position_encoding.into(),
        );

        Ok(text_size)
    }

    fn from_text_size(
        offset: TextSize,

View on GitHub (pinned to 26f38c119c)

Solutions

1. Pass a 1-indexed line number (first line is 1)
2. Convert 0-based editor coordinates to 1-based before calling the API

When it happens

Trigger: Thrown at crates/ty_wasm/src/lib.rs:1183 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of astral-sh/ruff@26f38c119c (2026-09-05). Data as JSON: /api/errors/f4cfe2eaf37acb3c. Report an issue: GitHub.