rust/compiler/rustc_errors/src/json/tests.rs

use std::str;

use rustc_span::BytePos;
use rustc_span::source_map::FilePathMapping;
use serde::Deserialize;

use super::*;
use crate::DiagCtxt;

#[derive(Deserialize, Debug, PartialEq, Eq)]
struct TestData {
    spans: Vec<SpanTestData>,
}

#[derive(Deserialize, Debug, PartialEq, Eq)]
struct SpanTestData {
    pub byte_start: u32,
    pub byte_end: u32,
    pub line_start: u32,
    pub column_start: u32,
    pub line_end: u32,
    pub column_end: u32,
}

struct Shared<T> {
    data: Arc<Mutex<T>>,
}

impl<T: Write> Write for Shared<T> {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        self.data.lock().unwrap().write(buf)
    }

    fn flush(&mut self) -> io::Result<()> {
        self.data.lock().unwrap().flush()
    }
}

/// Test the span yields correct positions in JSON.
fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
    rustc_span::create_default_session_globals_then(|| {
        let sm = Arc::new(SourceMap::new(FilePathMapping::empty()));
        sm.new_source_file(Path::new("test.rs").to_owned().into(), code.to_owned());
        let fallback_bundle =
            crate::fallback_fluent_bundle(vec![crate::DEFAULT_LOCALE_RESOURCE], false);

        let output = Arc::new(Mutex::new(Vec::new()));
        let je = JsonEmitter::new(
            Box::new(Shared { data: output.clone() }),
            Some(sm),
            fallback_bundle,
            true, // pretty
            HumanReadableErrorType::Short,
            ColorConfig::Never,
        );

        let span = Span::with_root_ctxt(BytePos(span.0), BytePos(span.1));
        DiagCtxt::new(Box::new(je)).handle().span_err(span, "foo");

        let bytes = output.lock().unwrap();
        let actual_output = str::from_utf8(&bytes).unwrap();
        let actual_output: TestData = serde_json::from_str(actual_output).unwrap();
        let spans = actual_output.spans;
        assert_eq!(spans.len(), 1);

        assert_eq!(expected_output, spans[0])
    })
}

#[test]
fn empty() {
    test_positions(" ", (0, 1), SpanTestData {
        byte_start: 0,
        byte_end: 1,
        line_start: 1,
        column_start: 1,
        line_end: 1,
        column_end: 2,
    })
}

#[test]
fn bom() {
    test_positions("\u{feff} ", (0, 1), SpanTestData {
        byte_start: 3,
        byte_end: 4,
        line_start: 1,
        column_start: 1,
        line_end: 1,
        column_end: 2,
    })
}

#[test]
fn lf_newlines() {
    test_positions("\nmod foo;\nmod bar;\n", (5, 12), SpanTestData {
        byte_start: 5,
        byte_end: 12,
        line_start: 2,
        column_start: 5,
        line_end: 3,
        column_end: 3,
    })
}

#[test]
fn crlf_newlines() {
    test_positions("\r\nmod foo;\r\nmod bar;\r\n", (5, 12), SpanTestData {
        byte_start: 6,
        byte_end: 14,
        line_start: 2,
        column_start: 5,
        line_end: 3,
        column_end: 3,
    })
}

#[test]
fn crlf_newlines_with_bom() {
    test_positions("\u{feff}\r\nmod foo;\r\nmod bar;\r\n", (5, 12), SpanTestData {
        byte_start: 9,
        byte_end: 17,
        line_start: 2,
        column_start: 5,
        line_end: 3,
        column_end: 3,
    })
}

#[test]
fn span_before_crlf() {
    test_positions("foo\r\nbar", (2, 3), SpanTestData {
        byte_start: 2,
        byte_end: 3,
        line_start: 1,
        column_start: 3,
        line_end: 1,
        column_end: 4,
    })
}

#[test]
fn span_on_crlf() {
    test_positions("foo\r\nbar", (3, 4), SpanTestData {
        byte_start: 3,
        byte_end: 5,
        line_start: 1,
        column_start: 4,
        line_end: 2,
        column_end: 1,
    })
}

#[test]
fn span_after_crlf() {
    test_positions("foo\r\nbar", (4, 5), SpanTestData {
        byte_start: 5,
        byte_end: 6,
        line_start: 2,
        column_start: 1,
        line_end: 2,
        column_end: 2,
    })
}