avoid sending empty results

empty results should convert to `clear diag`

Author: sumneko

changelog.md

@@ -1,5 +1,8 @@
 # changelog
 
+## 3.2.3
+* `FIX` diagnostic: send empty results to every file after startup
+
 ## 3.2.2
 `2022-4-26`
 * `FIX` diagnostic: `unused-function` cannot handle recursion correctly

script/provider/diagnostic.lua

@@ -128,6 +128,10 @@ local function mergeDiags(a, b, c)
     merge(b)
     merge(c)
 
+    if #t == 0 then
+        return nil
+    end
+
     return t
 end
 
@@ -253,9 +257,7 @@ function m.doDiagnostic(uri, isScopeDiag)
             version = version,
             diagnostics = full,
         })
-        if #full > 0 then
-            log.debug('publishDiagnostics', uri, #full)
-        end
+        log.debug('publishDiagnostics', uri, #full)
     end
 
     pushResult()