Remove incorrect assert

src/harness/unittests/extractRanges.ts

@@ -411,6 +411,12 @@ switch (x) {
             refactor.extractSymbol.Messages.cannotExtractRange.message
         ]);
 
+        testExtractRangeFailed("extractRangeFailed18",
+        `[#|{ 1;|] }`,
+        [
+            refactor.extractSymbol.Messages.cannotExtractRange.message
+        ]);
+
         testExtractRangeFailed("extract-method-not-for-token-expression-statement", `[#|a|]`, [refactor.extractSymbol.Messages.cannotExtractIdentifier.message]);
     });
 }

src/services/refactors/extractSymbol.ts

@@ -242,7 +242,6 @@ namespace ts.refactor.extractSymbol {
                 // they will never find `start` in `start.parent.statements`.
                 // Consider: We could support ranges like [|case 1:|] by refining them to just
                 // the expression.
-                Debug.assert(isCaseClause(start.parent) && span.start < start.parent.expression.end);
                 return { errors: [createFileDiagnostic(sourceFile, span.start, length, Messages.cannotExtractRange)] };
             }