readline: revert semver-major of 28109

PR-URL: nodejs#28109

Author: sam-github

lib/readline.js

@@ -121,7 +121,7 @@ function Interface(input, output, completer, terminal) {
     input = input.input;
   }
 
-  if (completer !== undefined && typeof completer !== 'function') {
+  if (completer && typeof completer !== 'function') {
     throw new ERR_INVALID_OPT_VALUE('completer', completer);
   }
 

test/parallel/test-readline-interface.js

@@ -367,25 +367,19 @@ function isWarned(emitter) {
       code: 'ERR_INVALID_OPT_VALUE'
     });
 
-    common.expectsError(function() {
+    common.mustCall(function() {
       readline.createInterface({
         input: fi,
         completer: ''
       });
-    }, {
-      type: TypeError,
-      code: 'ERR_INVALID_OPT_VALUE'
-    });
+    })();
 
-    common.expectsError(function() {
+    common.mustCall(function() {
       readline.createInterface({
         input: fi,
         completer: false
       });
-    }, {
-      type: TypeError,
-      code: 'ERR_INVALID_OPT_VALUE'
-    });
+    })();
   }
 
   // Constructor throws if historySize is not a positive number