Highlight exact source occurrences in LSP references and goto results

1 files changed, 29 insertions, 8 deletions

diff --git a/src/lsp/lsp_client.zig b/src/lsp/lsp_client.zig
index 8c6a0da9..c3762f08 100644
--- a/src/lsp/lsp_client.zig
+++ b/src/lsp/lsp_client.zig
@@ -948,15 +948,13 @@ fn emitRange(cx: *Cx, enc: Enc, uri: []const u8, range: ?std.json.Value, note: [
 
     const col = colBytes(lntext, r.sc, enc);
     const shown = lsp.rel(cx.base, path);
-    const rowtext = if (note.len > 0) note else lntext;
-    if (r.el == r.sl and r.ec > r.sc) {
-        // spanRow wants the protocol's EXCLUSIVE end as a 1-based inclusive
-        // byte column; converting the exclusive utf-16 end unit yields the
-        // exclusive byte column, which is the same number.
-        const end_col = colBytes(lntext, r.ec, enc);
-        try lsp.spanRow(cx.out, shown, r.sl, col, r.el, end_col, rowtext);
+    // A same-line exclusive end byte offset is also the displayed inclusive
+    // one-based column. Multi-line ranges display only their starting address.
+    const end_col = if (r.el == r.sl and r.ec > r.sc) colBytes(lntext, r.ec, enc) else col;
+    if (note.len == 0) {
+        try lsp.sourceSpanRow(cx.out, shown, r.sl, col, r.el, end_col, lntext);
     } else {
-        try lsp.row(cx.out, shown, r.sl, col, rowtext);
+        try lsp.spanRow(cx.out, shown, r.sl, col, r.el, end_col, note);
     }
     cx.rows += 1;
 }
@@ -2208,3 +2206,26 @@ test "the transport this host actually gives us is a pair, and both ends are clo
     try std.testing.expectEqual(@as(isize, msg.len), libc.read(sv[1], &got, got.len));
     try std.testing.expectEqualStrings(msg, got[0..msg.len]);
 }
+
+test "LSP source snippets preserve indentation with UTF16 byte ranges and prose stays trimmed" {
+    const gpa = std.testing.allocator;
+    const source = "\t  const 𝕏 = target; \t\r\n";
+    for ([_]bool{ false, true }) |multiline| {
+        var arena: std.heap.ArenaAllocator = .init(gpa);
+        defer arena.deinit();
+        const json = try std.fmt.allocPrint(arena.allocator(), "{{\"start\":{{\"line\":0,\"character\":14}},\"end\":{{\"line\":{d},\"character\":20}}}}", .{@as(u8, if (multiline) 1 else 0)});
+        const parsed = try std.json.parseFromSlice(std.json.Value, arena.allocator(), json, .{});
+        for ([_]bool{ false, true }) |prose| {
+            var buffer: [256]u8 = undefined;
+            var out: std.Io.Writer = .fixed(&buffer);
+            var cx: Cx = .{ .arena = arena.allocator(), .base = "/", .cur_path = "/file.c", .cur_src = source, .out = &out };
+            try emitRange(&cx, .utf16, "file:///file.c", parsed.value, if (prose) "  explanatory label \t" else "");
+            const expected = try std.fmt.allocPrint(arena.allocator(), "file.c:1:17{s} {s}\n", .{
+                if (multiline) "" else "-22",
+                if (prose) "explanatory label" else "\t  const 𝕏 = target; \t",
+            });
+            try std.testing.expectEqualStrings(expected, out.buffered());
+            try std.testing.expectEqual(@as(usize, 1), cx.rows);
+        }
+    }
+}