fn get_display_list_for_diagnostic()

in starlark/src/errors/mod.rs [171:224]

• 45 lines of code
• 1 McCabe index (conditional complexity)

fn get_display_list_for_diagnostic<'a>(
    annotation_label: &'a str,
    x: &'a Diagnostic,
    color: bool,
) -> DisplayList<'a> {
    fn convert_span_to_range_relative_to_first_line(
        diagnostic_span: Span,
        start_column: usize,
    ) -> (usize, usize) {
        let span_length = diagnostic_span.len() as usize;
        (start_column, start_column + span_length)
    }

    fn convert_span_to_slice<'a>(span: &'a FileSpan) -> Slice<'a> {
        let region = span.resolve_span();

        // we want the source_span to capture any whitespace ahead of the diagnostic span to
        // get the column numbers correct in the DisplayList, and any trailing source code
        // on the last line for context.
        let first_line_span = span.file.line_span(region.begin_line);
        let last_line_span = span.file.line_span(region.end_line);
        let source_span = span.span.merge(first_line_span).merge(last_line_span);

        Slice {
            source: span.file.source_span(source_span),
            line_start: 1 + region.begin_line,
            origin: Some(span.file.filename()),
            fold: false,
            annotations: vec![SourceAnnotation {
                label: "",
                annotation_type: AnnotationType::Error,
                range: convert_span_to_range_relative_to_first_line(span.span, region.begin_column),
            }],
        }
    }

    let slice = x.span.as_ref().map(convert_span_to_slice);

    let snippet = Snippet {
        title: Some(Annotation {
            label: Some(annotation_label),
            id: None,
            annotation_type: AnnotationType::Error,
        }),
        footer: Vec::new(),
        slices: slice.map(|s| vec![s]).unwrap_or_default(),
        opt: FormatOptions {
            color,
            ..Default::default()
        },
    };

    DisplayList::from(snippet)
}