Use ?. where it represents the intended semantics (#11512)

packages/babel-traverse/src/context.js

@@ -31,7 +31,7 @@ export default class TraversalContext {
 
     // check if we're going to traverse into this node
     const keys: ?Array<string> = t.VISITOR_KEYS[node.type];
-    if (!keys || !keys.length) return false;
+    if (!keys?.length) return false;
 
     // we need to traverse into this node so ensure that it has children to traverse into!
     for (const key of keys) {

packages/babel-traverse/src/path/context.js

@@ -236,7 +236,7 @@ export function setup(parentPath, container, listKey, key) {
 export function setKey(key) {
   this.key = key;
   this.node = this.container[this.key];
-  this.type = this.node && this.node.type;
+  this.type = this.node?.type;
 }
 
 export function requeue(pathToQueue = this) {

packages/babel-traverse/src/path/conversion.js

@@ -170,7 +170,7 @@ function hoistFunctionEnvironment(
       p.isClassProperty({ static: false })
     );
   });
-  const inConstructor = thisEnvFn && thisEnvFn.node.kind === "constructor";
+  const inConstructor = thisEnvFn?.node.kind === "constructor";
 
   if (thisEnvFn.isClassProperty()) {
     throw fnPath.buildCodeFrameError(

packages/babel-traverse/src/path/evaluation.js

@@ -160,7 +160,7 @@ function _evaluate(path, state) {
       return deopt(binding.path, state);
     }
 
-    if (binding && binding.hasValue) {
+    if (binding?.hasValue) {
       return binding.value;
     } else {
       if (node.name === "undefined") {

packages/babel-traverse/src/path/inference/index.js

@@ -53,7 +53,7 @@ export function _getTypeAnnotation(): ?Object {
   }
 
   inferer = inferers[this.parentPath.type];
-  if (inferer && inferer.validParent) {
+  if (inferer?.validParent) {
     return this.parentPath.getTypeAnnotation();
   }
 }

packages/babel-traverse/src/path/inference/inferers.js

@@ -10,7 +10,7 @@ export function VariableDeclarator() {
 
   let type = init.getTypeAnnotation();
 
-  if (type && type.type === "AnyTypeAnnotation") {
+  if (type?.type === "AnyTypeAnnotation") {
     // Detect "var foo = Array()" calls so we can optimize for arrays vs iterables.
     if (
       init.isCallExpression() &&

packages/babel-traverse/src/path/removal.js

@@ -7,7 +7,7 @@ export function remove() {
   this._assertUnremoved();
 
   this.resync();
-  if (!this.opts || !this.opts.noScope) {
+  if (!this.opts?.noScope) {
     this._removeFromScope();
   }
 

packages/babel-traverse/src/path/replacement.js

@@ -196,7 +196,7 @@ export function _replaceWith(node) {
     t.validate(this.parent, this.key, node);
   }
 
-  this.debug(`Replace with ${node && node.type}`);
+  this.debug(`Replace with ${node?.type}`);
 
   this.node = this.container[this.key] = node;
 }
@@ -217,7 +217,7 @@ export function replaceExpressionWithStatements(nodes: Array<Object>) {
   }
 
   const functionParent = this.getFunctionParent();
-  const isParentAsync = functionParent && functionParent.is("async");
+  const isParentAsync = functionParent?.is("async");
 
   const container = t.arrowFunctionExpression([], t.blockStatement(nodes));
 

packages/babel-traverse/src/scope/index.js

@@ -294,7 +294,7 @@ export default class Scope {
     const cached = scopeCache.get(node);
     // Sometimes, a scopable path is placed higher in the AST tree.
     // In these cases, have to create a new Scope.
-    if (cached && cached.path === path) {
+    if (cached?.path === path) {
       return cached;
     }
     scopeCache.set(node, this);
@@ -322,7 +322,7 @@ export default class Scope {
 
   get parent() {
     const parent = this.path.findParent(p => p.isScope());
-    return parent && parent.scope;
+    return parent?.scope;
   }
 
   get parentBlock() {
@@ -523,7 +523,7 @@ export default class Scope {
   toArray(node: Object, i?: number) {
     if (t.isIdentifier(node)) {
       const binding = this.getBinding(node.name);
-      if (binding && binding.constant && binding.path.isGenericType("Array")) {
+      if (binding?.constant && binding.path.isGenericType("Array")) {
         return node;
       }
     }
@@ -1014,13 +1014,12 @@ export default class Scope {
   }
 
   getBindingIdentifier(name: string) {
-    const info = this.getBinding(name);
-    return info && info.identifier;
+    return this.getBinding(name)?.identifier;
   }
 
   getOwnBindingIdentifier(name: string) {
     const binding = this.bindings[name];
-    return binding && binding.identifier;
+    return binding?.identifier;
   }
 
   hasOwnBinding(name: string) {
@@ -1038,7 +1037,7 @@ export default class Scope {
   }
 
   parentHasBinding(name: string, noGlobals?) {
-    return this.parent && this.parent.hasBinding(name, noGlobals);
+    return this.parent?.hasBinding(name, noGlobals);
   }
 
   /**
@@ -1060,10 +1059,7 @@ export default class Scope {
 
   removeBinding(name: string) {
     // clear literal binding
-    const info = this.getBinding(name);
-    if (info) {
-      info.scope.removeOwnBinding(name);
-    }
+    this.getBinding(name)?.scope.removeOwnBinding(name);
 
     // clear uids with this name - https://github.com/babel/babel/issues/2101
     let scope = this;