Use numbers instead of strings for error codes

Author: acdlite

scripts/error-codes/__tests__/__snapshots__/minify-error-messages.js.snap

@@ -32,7 +32,7 @@ import invariant from 'shared/invariant';
     if (__DEV__) {
       throw _ReactError(\`Do not override existing functions.\`);
     } else {
-      throw _ReactErrorProd('16');
+      throw _ReactErrorProd(16);
     }
   }
 })();
@@ -41,7 +41,7 @@ import invariant from 'shared/invariant';
     if (__DEV__) {
       throw _ReactError(\`Do not override existing functions.\`);
     } else {
-      throw _ReactErrorProd('16');
+      throw _ReactErrorProd(16);
     }
   }
 })();"
@@ -57,7 +57,7 @@ import invariant from 'shared/invariant';
     if (__DEV__) {
       throw _ReactError(\`Do not override existing functions.\`);
     } else {
-      throw _ReactErrorProd('16');
+      throw _ReactErrorProd(16);
     }
   }
 })();"
@@ -73,7 +73,7 @@ import invariant from 'shared/invariant';
     if (__DEV__) {
       throw _ReactError(\`Expected a component class, got \${Foo}.\${Bar}\`);
     } else {
-      throw _ReactErrorProd('18', [Foo, Bar]);
+      throw _ReactErrorProd(18, [Foo, Bar]);
     }
   }
 })();"
@@ -89,7 +89,7 @@ import invariant from 'shared/invariant';
     if (__DEV__) {
       throw _ReactError(\`Expected \${foo} target to be an array; got \${bar}\`);
     } else {
-      throw _ReactErrorProd('7', [foo, bar]);
+      throw _ReactErrorProd(7, [foo, bar]);
     }
   }
 })();"

scripts/error-codes/minify-error-messages.js

@@ -65,7 +65,7 @@ module.exports = function(babel) {
           );
           const errorMap = invertObject(existingErrorMap);
 
-          const prodErrorId = errorMap[errorMsgLiteral];
+          let prodErrorId = errorMap[errorMsgLiteral];
           if (prodErrorId === undefined) {
             // There is no error code for this message. We use a lint rule to
             // enforce that messages can be minified, so assume this is
@@ -83,6 +83,7 @@ module.exports = function(babel) {
             );
             return;
           }
+          prodErrorId = parseInt(prodErrorId, 10);
 
           // Import ReactErrorProd
           const reactErrorProdIdentfier = file.addImport(
@@ -97,7 +98,7 @@ module.exports = function(babel) {
             t.callExpression(
               reactErrorProdIdentfier,
               [
-                t.stringLiteral(prodErrorId),
+                t.numericLiteral(prodErrorId),
                 errorMsgExpressions.length > 0
                   ? t.arrayExpression(errorMsgExpressions)
                   : undefined,