fix(linter): make more resilient against some edge case behavior

lua/linter.lua

@@ -349,10 +349,18 @@ function Linter:run()
                 log.error(out.stderr)
             end
 
+            if not output or output == "" then
+                return
+            end
+
+            local lines = vim.split(output, "\n", { trimempty = true })
+
             if self.config.json then
+                local diagnostics = {}
+                for _, line in ipairs(lines) do
                     local ok, json = pcall(
                         vim.json.decode,
-                    output,
+                        line,
                         { luanil = { object = true, array = true } }
                     )
                     if not ok then
@@ -361,8 +369,13 @@ function Linter:run()
                         return
                     end
 
-                local diagnostics = self:process_json_output(json)
+                    local diags = self:process_json_output(json)
-                if diagnostics then
+                    if diags then
+                        vim.list_extend(diagnostics, diags)
+                    end
+                end
+
+                if #diagnostics > 0 then
                     if self.config.hook then
                         self.config.hook(self, diagnostics)
                     end
@@ -372,9 +385,8 @@ function Linter:run()
                 return
             end
 
-            local output_lines = vim.fn.split(output, "\n", false)
             local diagnostics = {}
-            for _, line in ipairs(output_lines) do
+            for _, line in ipairs(lines) do
                 local ok, resp = pcall(
                     vim.diagnostic.match,
                     line,