1 files changed, 128 insertions, 0 deletions

diff --git a/crates/ide_db/src/line_index/tests.rs b/crates/ide_db/src/line_index/tests.rs
new file mode 100644
index 000000000..05f7484e8
--- /dev/null
+++ b/crates/ide_db/src/line_index/tests.rs
@@ -0,0 +1,128 @@
+use super::*;
+
+#[test]
+fn test_line_index() {
+    let text = "hello\nworld";
+    let index = LineIndex::new(text);
+    assert_eq!(index.line_col(0.into()), LineCol { line: 0, col_utf16: 0 });
+    assert_eq!(index.line_col(1.into()), LineCol { line: 0, col_utf16: 1 });
+    assert_eq!(index.line_col(5.into()), LineCol { line: 0, col_utf16: 5 });
+    assert_eq!(index.line_col(6.into()), LineCol { line: 1, col_utf16: 0 });
+    assert_eq!(index.line_col(7.into()), LineCol { line: 1, col_utf16: 1 });
+    assert_eq!(index.line_col(8.into()), LineCol { line: 1, col_utf16: 2 });
+    assert_eq!(index.line_col(10.into()), LineCol { line: 1, col_utf16: 4 });
+    assert_eq!(index.line_col(11.into()), LineCol { line: 1, col_utf16: 5 });
+    assert_eq!(index.line_col(12.into()), LineCol { line: 1, col_utf16: 6 });
+
+    let text = "\nhello\nworld";
+    let index = LineIndex::new(text);
+    assert_eq!(index.line_col(0.into()), LineCol { line: 0, col_utf16: 0 });
+    assert_eq!(index.line_col(1.into()), LineCol { line: 1, col_utf16: 0 });
+    assert_eq!(index.line_col(2.into()), LineCol { line: 1, col_utf16: 1 });
+    assert_eq!(index.line_col(6.into()), LineCol { line: 1, col_utf16: 5 });
+    assert_eq!(index.line_col(7.into()), LineCol { line: 2, col_utf16: 0 });
+}
+
+#[test]
+fn test_char_len() {
+    assert_eq!('メ'.len_utf8(), 3);
+    assert_eq!('メ'.len_utf16(), 1);
+}
+
+#[test]
+fn test_empty_index() {
+    let col_index = LineIndex::new(
+        "
+const C: char = 'x';
+",
+    );
+    assert_eq!(col_index.utf16_lines.len(), 0);
+}
+
+#[test]
+fn test_single_char() {
+    let col_index = LineIndex::new(
+        "
+const C: char = 'メ';
+",
+    );
+
+    assert_eq!(col_index.utf16_lines.len(), 1);
+    assert_eq!(col_index.utf16_lines[&1].len(), 1);
+    assert_eq!(col_index.utf16_lines[&1][0], Utf16Char { start: 17.into(), end: 20.into() });
+
+    // UTF-8 to UTF-16, no changes
+    assert_eq!(col_index.utf8_to_utf16_col(1, 15.into()), 15);
+
+    // UTF-8 to UTF-16
+    assert_eq!(col_index.utf8_to_utf16_col(1, 22.into()), 20);
+
+    // UTF-16 to UTF-8, no changes
+    assert_eq!(col_index.utf16_to_utf8_col(1, 15), TextSize::from(15));
+
+    // UTF-16 to UTF-8
+    assert_eq!(col_index.utf16_to_utf8_col(1, 19), TextSize::from(21));
+
+    let col_index = LineIndex::new("a𐐏b");
+    assert_eq!(col_index.utf16_to_utf8_col(0, 3), TextSize::from(5));
+}
+
+#[test]
+fn test_string() {
+    let col_index = LineIndex::new(
+        "
+const C: char = \"メ メ\";
+",
+    );
+
+    assert_eq!(col_index.utf16_lines.len(), 1);
+    assert_eq!(col_index.utf16_lines[&1].len(), 2);
+    assert_eq!(col_index.utf16_lines[&1][0], Utf16Char { start: 17.into(), end: 20.into() });
+    assert_eq!(col_index.utf16_lines[&1][1], Utf16Char { start: 21.into(), end: 24.into() });
+
+    // UTF-8 to UTF-16
+    assert_eq!(col_index.utf8_to_utf16_col(1, 15.into()), 15);
+
+    assert_eq!(col_index.utf8_to_utf16_col(1, 21.into()), 19);
+    assert_eq!(col_index.utf8_to_utf16_col(1, 25.into()), 21);
+
+    assert!(col_index.utf8_to_utf16_col(2, 15.into()) == 15);
+
+    // UTF-16 to UTF-8
+    assert_eq!(col_index.utf16_to_utf8_col(1, 15), TextSize::from(15));
+
+    // メ UTF-8: 0xE3 0x83 0xA1, UTF-16: 0x30E1
+    assert_eq!(col_index.utf16_to_utf8_col(1, 17), TextSize::from(17)); // first メ at 17..20
+    assert_eq!(col_index.utf16_to_utf8_col(1, 18), TextSize::from(20)); // space
+    assert_eq!(col_index.utf16_to_utf8_col(1, 19), TextSize::from(21)); // second メ at 21..24
+
+    assert_eq!(col_index.utf16_to_utf8_col(2, 15), TextSize::from(15));
+}
+
+#[test]
+fn test_splitlines() {
+    fn r(lo: u32, hi: u32) -> TextRange {
+        TextRange::new(lo.into(), hi.into())
+    }
+
+    let text = "a\nbb\nccc\n";
+    let line_index = LineIndex::new(text);
+
+    let actual = line_index.lines(r(0, 9)).collect::<Vec<_>>();
+    let expected = vec![r(0, 2), r(2, 5), r(5, 9)];
+    assert_eq!(actual, expected);
+
+    let text = "";
+    let line_index = LineIndex::new(text);
+
+    let actual = line_index.lines(r(0, 0)).collect::<Vec<_>>();
+    let expected = vec![];
+    assert_eq!(actual, expected);
+
+    let text = "\n";
+    let line_index = LineIndex::new(text);
+
+    let actual = line_index.lines(r(0, 1)).collect::<Vec<_>>();
+    let expected = vec![r(0, 1)];
+    assert_eq!(actual, expected)
+}