repl: refactor code for readability

Backport-PR-URL: #19244
PR-URL: #17919
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Weijia Wang <starkwang@126.com>
Reviewed-By: Khaidi Chu <i@2333.moe>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Lance Ball <lball@redhat.com>

lib/repl.js

@@ -320,15 +320,10 @@ function REPLServer(prompt,
       // Use stdin and stdout as the default streams if none were given
       stream = process;
     }
-    if (stream.stdin && stream.stdout) {
-      // We're given custom object with 2 streams, or the `process` object
-      input = stream.stdin;
-      output = stream.stdout;
-    } else {
-      // We're given a duplex readable/writable Stream, like a `net.Socket`
-      input = stream;
-      output = stream;
-    }
+    // We're given a duplex readable/writable Stream, like a `net.Socket`
+    // or a custom object with 2 streams, or the `process` object
+    input = stream.stdin || stream;
+    output = stream.stdout || stream;
   }
 
   self.inputStream = input;
@@ -663,7 +658,7 @@ REPLServer.prototype.createContext = function() {
     Object.defineProperty(context, 'console', {
       configurable: true,
       enumerable: true,
-      get: () => _console
+      value: _console
     });
 
     var names = Object.getOwnPropertyNames(global);
@@ -1035,19 +1030,16 @@ function complete(line, callback) {
                   break;
                 }
               }
-            } catch (e) {
-              // console.log("completion error walking prototype chain:" + e);
-            }
+            } catch (e) {}
           }
 
           if (memberGroups.length) {
             for (i = 0; i < memberGroups.length; i++) {
-              completionGroups.push(memberGroups[i].map(function(member) {
-                return expr + '.' + member;
-              }));
+              completionGroups.push(
+                memberGroups[i].map((member) => `${expr}.${member}`));
             }
             if (filter) {
-              filter = expr + '.' + filter;
+              filter = `${expr}.${filter}`;
             }
           }
 
@@ -1068,9 +1060,8 @@ function complete(line, callback) {
     if (completionGroups.length && filter) {
       var newCompletionGroups = [];
       for (i = 0; i < completionGroups.length; i++) {
-        group = completionGroups[i].filter(function(elem) {
-          return elem.indexOf(filter) === 0;
-        });
+        group = completionGroups[i]
+          .filter((elem) => elem.indexOf(filter) === 0);
         if (group.length) {
           newCompletionGroups.push(group);
         }
@@ -1400,55 +1391,33 @@ function isCodeRecoverable(code) {
 
     if (previous === '\\' && (stringLiteral || isRegExpLiteral)) {
       current = null;
-      continue;
-    }
-
-    if (stringLiteral) {
+    } else if (stringLiteral) {
       if (stringLiteral === current) {
         stringLiteral = null;
       }
-      continue;
-    } else {
-      if (isRegExpLiteral && current === '/') {
-        isRegExpLiteral = false;
-        continue;
-      }
-
-      if (isBlockComment && previous === '*' && current === '/') {
-        isBlockComment = false;
-        continue;
-      }
-
-      if (isSingleComment && current === '\n') {
-        isSingleComment = false;
-        continue;
-      }
-
-      if (isBlockComment || isRegExpLiteral || isSingleComment) continue;
-
+    } else if (isRegExpLiteral && current === '/') {
+      isRegExpLiteral = false;
+    } else if (isBlockComment && previous === '*' && current === '/') {
+      isBlockComment = false;
+    } else if (isSingleComment && current === '\n') {
+      isSingleComment = false;
+    } else if (!isBlockComment && !isRegExpLiteral && !isSingleComment) {
       if (current === '/' && previous === '/') {
         isSingleComment = true;
-        continue;
-      }
-
-      if (previous === '/') {
+      } else if (previous === '/') {
         if (current === '*') {
           isBlockComment = true;
-        } else if (
           // Distinguish between a division operator and the start of a regex
           // by examining the non-whitespace character that precedes the /
-          [null, '(', '[', '{', '}', ';'].includes(prevTokenChar)
-        ) {
+        } else if ([null, '(', '[', '{', '}', ';'].includes(prevTokenChar)) {
           isRegExpLiteral = true;
         }
-        continue;
+      } else {
+        if (current.trim()) prevTokenChar = current;
+        if (current === '\'' || current === '"') {
+          stringLiteral = current;
+        }
       }
-
-      if (current.trim()) prevTokenChar = current;
-    }
-
-    if (current === '\'' || current === '"') {
-      stringLiteral = current;
     }
   }