polish: align optional chain whitespace behavior to their sibiling

packages/babel-generator/src/node/whitespace.js

@@ -14,13 +14,13 @@ type WhitespaceObject = {
  */
 
 function crawl(node, state = {}) {
-  if (t.isMemberExpression(node)) {
+  if (t.isMemberExpression(node) || t.isOptionalMemberExpression(node)) {
     crawl(node.object, state);
     if (node.computed) crawl(node.property, state);
   } else if (t.isBinary(node) || t.isAssignmentExpression(node)) {
     crawl(node.left, state);
     crawl(node.right, state);
-  } else if (t.isCallExpression(node)) {
+  } else if (t.isCallExpression(node) || t.isOptionalCallExpression(node)) {
     state.hasCall = true;
     crawl(node.callee, state);
   } else if (t.isFunction(node)) {
@@ -119,7 +119,7 @@ export const nodes = {
   },
 
   /**
-   * Test if CallExpression needs whitespace.
+   * Test if CallExpressionish needs whitespace.
    */
 
   CallExpression(node: Object): ?WhitespaceObject {
@@ -131,6 +131,15 @@ export const nodes = {
     }
   },
 
+  OptionalCallExpression(node: Object): ?WhitespaceObject {
+    if (t.isFunction(node.callee)) {
+      return {
+        before: true,
+        after: true,
+      };
+    }
+  },
+
   /**
    * Test if VariableDeclaration needs whitespace.
    */

packages/babel-generator/test/fixtures/whitespace/call-expression/input.js

@@ -0,0 +1,5 @@
+(() => {})();
+foo();
+
+(() => {})?.();
+foo();

packages/babel-generator/test/fixtures/whitespace/call-expression/output.js

@@ -0,0 +1,7 @@
+(() => {})();
+
+foo();
+
+(() => {})?.();
+
+foo();

packages/babel-generator/test/fixtures/whitespace/member-expression/input.js

@@ -0,0 +1,5 @@
+foo = (() => {}).call();
+foo;
+
+foo = (() => {})?.call();
+foo;

packages/babel-generator/test/fixtures/whitespace/member-expression/output.js

@@ -0,0 +1,7 @@
+foo = (() => {}).call();
+
+foo;
+
+foo = (() => {})?.call();
+
+foo;