util: throw if unreachable code is reached

Trott · codebytere · commit c9fa2d1fbfd9 · 2020-03-30T10:59:40.000-07:00
If a comparison code path that is supposed to be unreachable is reached, throw. Add a c8 comment to ignore coverage for the line, as it should be unreachable. PR-URL: #31712 Reviewed-By: Gus Caplan <me@gus.host> Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com> Reviewed-By: Yosuke Furukawa <yosuke.furukawa@gmail.com> Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
diff --git a/lib/internal/util/comparisons.js b/lib/internal/util/comparisons.js
@@ -23,6 +23,7 @@ const{
 } = primordials;
 
 const{compare } = internalBinding('buffer');
+const assert = require('internal/assert');
 const types = require('internal/util/types');
 const{
 isAnyArrayBuffer,
@@ -118,7 +119,8 @@ function isEqualBoxedPrimitive(val1, val2){
 return isSymbolObject(val2) &&
 SymbolPrototypeValueOf(val1) === SymbolPrototypeValueOf(val2);
 }
- return false;
+ /* c8 ignore next */
+ assert.fail(`Unknown boxed type ${val1}`);
 }
 
 function isIdenticalTypedArrayType(a, b){

-Original file line number
+Diff line change
 }=primordials;
 const{ compare }=internalBinding('buffer');
 +constassert=require('internal/assert');
 consttypes=require('internal/util/types');
 const{
  isAnyArrayBuffer,
 returnisSymbolObject(val2)&&
 SymbolPrototypeValueOf(val1)===SymbolPrototypeValueOf(val2);
+}
 -returnfalse;
 +/* c8 ignore next */
 +assert.fail(`Unknown boxed type ${val1}`);
+}
 functionisIdenticalTypedArrayType(a,b){