Be sure that TS files can be run without TS

Author: ai

lib/math.ts

@@ -1,13 +1,11 @@
-enum Priority {
-  High = 2,
-  Low = 1
-}
+const HIGH_PRIORITY = 2
+const LOW_PRIORITY = 1
 
 const OPERATORS = {
-  '-': Priority.Low,
-  '*': Priority.High,
-  '/': Priority.High,
-  '+': Priority.Low
+  '-': LOW_PRIORITY,
+  '*': HIGH_PRIORITY,
+  '/': HIGH_PRIORITY,
+  '+': LOW_PRIORITY
 }
 
 type Operator = keyof typeof OPERATORS

tsconfig.json

@@ -2,6 +2,7 @@
   "compilerOptions": {
     "allowImportingTsExtensions": true,
     "verbatimModuleSyntax": true,
+    "erasableSyntaxOnly": true,
     "moduleResolution": "node",
     "esModuleInterop": true,
     "skipLibCheck": true,