fix(filter): handle mixed whole-line and column diagnostics (#179)

Author: rachartier

lua/tiny-inline-diagnostic/filter.lua

@@ -34,17 +34,21 @@ function M.at_position(opts, diagnostics, line, col)
   end
 
   local current_pos_diags = vim.tbl_filter(function(diag)
-    if diag.lnum ~= line then
-      return false
-    end
-    if diag.col == 0 and diag.end_col == 0 then
-      return true
-    end
-    return col >= diag.col and col <= diag.end_col
+    return diag.lnum == line and col >= diag.col and col <= diag.end_col
   end, diagnostics)
 
   if opts.options.show_diags_only_under_cursor then
-    return current_pos_diags
+    local seen = {}
+    for _, d in ipairs(current_pos_diags) do
+      seen[d] = true
+    end
+    local result = vim.list_extend({}, current_pos_diags)
+    for _, d in ipairs(diags_on_line) do
+      if not seen[d] and d.col == 0 and d.end_col == 0 then
+        result[#result + 1] = d
+      end
+    end
+    return result
   else
     return #current_pos_diags > 0 and current_pos_diags or diags_on_line
   end

tests/test_filter.lua

@@ -86,6 +86,38 @@ T["at_position"]["matches whole line when diagnostic has no column info under de
   MiniTest.expect.equality(result[1].lnum, 5)
 end
 
+T["at_position"]["default mode keeps line fallback when mixed whole-line and column-specific diagnostics"] = function()
+  local diagnostics = {
+    H.make_diagnostic({ lnum = 5, col = 0, end_col = 0 }),
+    H.make_diagnostic({ lnum = 5, col = 10, end_col = 20 }),
+  }
+
+  local result = filter.at_position({ options = {} }, diagnostics, 5, 5)
+  MiniTest.expect.equality(#result, 2)
+end
+
+T["at_position"]["default mode returns only column-specific diagnostic when cursor is on it"] = function()
+  local diagnostics = {
+    H.make_diagnostic({ lnum = 5, col = 0, end_col = 0 }),
+    H.make_diagnostic({ lnum = 5, col = 10, end_col = 20 }),
+  }
+
+  local result = filter.at_position({ options = {} }, diagnostics, 5, 15)
+  MiniTest.expect.equality(#result, 1)
+  MiniTest.expect.equality(result[1].col, 10)
+end
+
+T["at_position"]["show_diags_only_under_cursor merges whole-line and under-cursor diagnostics"] = function()
+  local diagnostics = {
+    H.make_diagnostic({ lnum = 5, col = 0, end_col = 0 }),
+    H.make_diagnostic({ lnum = 5, col = 10, end_col = 20 }),
+  }
+
+  local result =
+    filter.at_position({ options = { show_diags_only_under_cursor = true } }, diagnostics, 5, 15)
+  MiniTest.expect.equality(#result, 2)
+end
+
 T["under_cursor"] = MiniTest.new_set()
 
 T["under_cursor"]["returns empty for invalid buffer"] = function()