fix diagnostics filter

lua/spike/diagnostics.lua

@@ -17,12 +17,18 @@ end
 local orig_diag_virt_handler = vim.diagnostic.handlers.virtual_text
 local ns = vim.api.nvim_create_namespace("my_diagnostics")
 
-local filter_diagnostics = function(diagnostics, level)
+local filter_diagnostics = function(diagnostics, level, bufnr)
+    assert(bufnr, "bufnr is required")
     local filtered_diag = {}
     if level == -1 then return {} end
+    if not diagnostics then return {} end
     for _, d in ipairs(diagnostics) do
         if d.severity <= level then
-            table.insert(filtered_diag, 1, d)
+            -- check if diagnostic line is out of range in current buffer
+            local lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, true)
+            if d.end_lnum <= #lines then
+                table.insert(filtered_diag, 1, d)
+            end
         end
     end
     return filtered_diag
@@ -36,7 +42,7 @@ M.set_diagnostics_level = function(level)
         show = function(_, bufnr, _, opts)
             -- get all diagnostics for local buffer
             local diagnostics = vim.diagnostic.get(bufnr)
-            filtered = filter_diagnostics(diagnostics, level)
+            local filtered = filter_diagnostics(diagnostics, level, bufnr)
             -- filter diags based on severity
             orig_diag_virt_handler.show(ns, bufnr, filtered, opts)
         end,
@@ -45,13 +51,13 @@ M.set_diagnostics_level = function(level)
         end
     }
 
-    bufnr = vim.api.nvim_get_current_buf()
+    local bufnr = vim.api.nvim_get_current_buf()
     -- hide all diagnostics
-    vim.diagnostic.hide(nil, bufnr) 
+    vim.diagnostic.hide(nil, bufnr)
 
     local diags = vim.diagnostic.get(bufnr)
     if #diags > 0 then
-        filtered = filter_diagnostics(diags, level)
+        local filtered = filter_diagnostics(diags, level, bufnr)
         vim.diagnostic.show(ns, bufnr, filtered)
     end