[BugFix] : OptionalChaining Bug fixes (#7288)

* Added optionalExpression types to babylon and babel-types

* OptionalChain transforms bug fix

* Added OptionalExpressions to babel-generator. Fixed OptionalChain Bugs

* Removed 'optionalChain' from newExpression and added test cases

* Added test cases for optionalChain

* Update index.js

packages/babel-generator/src/generators/expressions.js

@@ -95,7 +95,34 @@ export function Decorator(node: Object) {
   this.newline();
 }
 
-export function CallExpression(node: Object) {
+export function OptionalMemberExpression(node: Object) {
+  this.print(node.object, node);
+
+  if (!node.computed && t.isMemberExpression(node.property)) {
+    throw new TypeError("Got a MemberExpression for MemberExpression property");
+  }
+
+  let computed = node.computed;
+  if (t.isLiteral(node.property) && typeof node.property.value === "number") {
+    computed = true;
+  }
+  if (node.optional) {
+    this.token("?.");
+  }
+
+  if (computed) {
+    this.token("[");
+    this.print(node.property, node);
+    this.token("]");
+  } else {
+    if (!node.optional) {
+      this.token(".");
+    }
+    this.print(node.property, node);
+  }
+}
+
+export function OptionalCallExpression(node: Object) {
   this.print(node.callee, node);
 
   this.print(node.typeParameters, node); // TS
@@ -108,6 +135,15 @@ export function CallExpression(node: Object) {
   this.token(")");
 }
 
+export function CallExpression(node: Object) {
+  this.print(node.callee, node);
+
+  this.print(node.typeParameters, node); // TS
+  this.token("(");
+  this.printList(node.arguments, node);
+  this.token(")");
+}
+
 export function Import() {
   this.word("import");
 }
@@ -203,17 +239,12 @@ export function MemberExpression(node: Object) {
     computed = true;
   }
 
-  if (node.optional) {
-    this.token("?.");
-  }
   if (computed) {
     this.token("[");
     this.print(node.property, node);
     this.token("]");
   } else {
-    if (!node.optional) {
+    this.token(".");
-      this.token(".");
-    }
     this.print(node.property, node);
   }
 }

packages/babel-generator/test/fixtures/types/Optional-NewExpression/input.js

@@ -1,39 +0,0 @@
-new foo?.();
-new foo?.("foo");
-new foo?.("foo", "bar");
-new foo?.(bar());
-new foo?.(bar("test"));
-foo(new bar?.());
-foo(new bar?.("test"));
-
-new a.foo?.();
-new a.foo?.("foo");
-new a.foo?.("foo", "bar");
-new a.foo?.(bar());
-new a.foo?.(bar("test"));
-a.foo(new bar?.());
-a.foo(new bar?.("test"));
-
-new a?.foo?.();
-new a?.foo?.("foo");
-new a?.foo?.("foo", "bar");
-new a?.foo?.(bar());
-new a?.foo?.(bar("test"));
-a?.foo(new bar?.());
-a?.foo(new bar?.("test"));
-
-new a.foo?.().baz;
-new a.foo?.("foo").baz;
-new a.foo?.("foo", "bar").baz;
-new a.foo?.(bar()).baz;
-new a.foo?.(bar("test")).baz;
-a.foo(new bar?.()).baz;
-a.foo(new bar?.("test")).baz;
-
-new a.foo?.()?.baz;
-new a.foo?.("foo")?.baz;
-new a.foo?.("foo", "bar")?.baz;
-new a.foo?.(bar())?.baz;
-new a.foo?.(bar("test"))?.baz;
-a.foo(new bar?.())?.baz;
-a.foo(new bar?.("test"))?.baz;

packages/babel-generator/test/fixtures/types/Optional-NewExpression/options.json

@@ -1 +0,0 @@
-{ "plugins": ["optionalChaining"] }

packages/babel-generator/test/fixtures/types/Optional-NewExpression/output.js

@@ -1,35 +0,0 @@
-new foo?.();
-new foo?.("foo");
-new foo?.("foo", "bar");
-new foo?.(bar());
-new foo?.(bar("test"));
-foo(new bar?.());
-foo(new bar?.("test"));
-new a.foo?.();
-new a.foo?.("foo");
-new a.foo?.("foo", "bar");
-new a.foo?.(bar());
-new a.foo?.(bar("test"));
-a.foo(new bar?.());
-a.foo(new bar?.("test"));
-new a?.foo?.();
-new a?.foo?.("foo");
-new a?.foo?.("foo", "bar");
-new a?.foo?.(bar());
-new a?.foo?.(bar("test"));
-a?.foo(new bar?.());
-a?.foo(new bar?.("test"));
-new a.foo?.().baz;
-new a.foo?.("foo").baz;
-new a.foo?.("foo", "bar").baz;
-new a.foo?.(bar()).baz;
-new a.foo?.(bar("test")).baz;
-a.foo(new bar?.()).baz;
-a.foo(new bar?.("test")).baz;
-new a.foo?.()?.baz;
-new a.foo?.("foo")?.baz;
-new a.foo?.("foo", "bar")?.baz;
-new a.foo?.(bar())?.baz;
-new a.foo?.(bar("test"))?.baz;
-a.foo(new bar?.())?.baz;
-a.foo(new bar?.("test"))?.baz;

packages/babel-plugin-proposal-optional-chaining/src/index.js

@@ -9,15 +9,20 @@ export default function(api, options) {
     const optionals = [];
 
     let objectPath = path;
-    while (objectPath.isMemberExpression() || objectPath.isCallExpression()) {
+    while (
+      objectPath.isOptionalMemberExpression() ||
+      objectPath.isOptionalCallExpression()
+    ) {
       const { node } = objectPath;
       if (node.optional) {
         optionals.push(node);
       }
 
-      if (objectPath.isMemberExpression()) {
+      if (objectPath.isOptionalMemberExpression()) {
+        objectPath.node.type = "MemberExpression";
         objectPath = objectPath.get("object");
       } else {
+        objectPath.node.type = "CallExpression";
         objectPath = objectPath.get("callee");
       }
     }
@@ -101,21 +106,10 @@ export default function(api, options) {
     return path.find(path => {
       const { parentPath } = path;
 
-      if (path.key == "left" && parentPath.isAssignmentExpression()) {
+      if (path.key == "object" && parentPath.isOptionalMemberExpression()) {
-        throw path.buildCodeFrameError(
-          "Illegal optional chain in assignment expression",
-        );
-      }
-      if (path.key == "argument" && parentPath.isUpdateExpression()) {
-        throw path.buildCodeFrameError(
-          "Illegal optional chain in update expression",
-        );
-      }
-
-      if (path.key == "object" && parentPath.isMemberExpression()) {
         return false;
       }
-      if (path.key == "callee" && parentPath.isCallExpression()) {
+      if (path.key == "callee" && parentPath.isOptionalCallExpression()) {
         return false;
       }
       if (
@@ -133,7 +127,7 @@ export default function(api, options) {
     inherits: syntaxOptionalChaining,
 
     visitor: {
-      "MemberExpression|CallExpression"(path) {
+      "OptionalCallExpression|OptionalMemberExpression"(path) {
         if (!path.node.optional) {
           return;
         }

packages/babel-plugin-proposal-optional-chaining/test/fixtures/general/lhs-assignment-read-and-update/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Illegal optional chain in assignment expression"
+  "throws": "Invalid left-hand side in assignment expression"
 }

packages/babel-plugin-proposal-optional-chaining/test/fixtures/general/lhs-assignment/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Illegal optional chain in assignment expression"
+  "throws": "Invalid left-hand side in assignment expression"
 }

packages/babel-plugin-proposal-optional-chaining/test/fixtures/general/lhs-update/options.json

@@ -1,3 +1,3 @@
 {
-  "throws": "Illegal optional chain in update expression"
+  "throws": "Invalid left-hand side in postfix operation"
 }

packages/babel-types/README.md

@@ -1590,6 +1590,38 @@ Aliases: `Flow`, `FlowDeclaration`, `Statement`, `Declaration`
 
 ---
 
+### optionalCallExpression
+```javascript
+t.optionalCallExpression(callee, arguments, optional)
+```
+
+See also `t.isOptionalCallExpression(node, opts)` and `t.assertOptionalCallExpression(node, opts)`.
+
+Aliases: `Expression`
+
+ - `callee`: `Expression` (required)
+ - `arguments`: `Array<Expression | SpreadElement | JSXNamespacedName>` (required)
+ - `optional`: `boolean` (required)
+ - `typeParameters`: `TypeParameterInstantiation | TSTypeParameterInstantiation` (default: `null`)
+
+---
+
+### optionalMemberExpression
+```javascript
+t.optionalMemberExpression(object, property, computed, optional)
+```
+
+See also `t.isOptionalMemberExpression(node, opts)` and `t.assertOptionalMemberExpression(node, opts)`.
+
+Aliases: `Expression`
+
+ - `object`: `Expression` (required)
+ - `property`: `any` (required)
+ - `computed`: `boolean` (default: `false`)
+ - `optional`: `boolean` (required)
+
+---
+
 ### parenthesizedExpression
 ```javascript
 t.parenthesizedExpression(expression)

packages/babel-types/src/asserts/generated/index.js

@@ -651,6 +651,18 @@ export function assertBindExpression(node: Object, opts?: Object = {}): void {
 export function assertClassProperty(node: Object, opts?: Object = {}): void {
   assert("ClassProperty", node, opts);
 }
+export function assertOptionalMemberExpression(
+  node: Object,
+  opts?: Object = {},
+): void {
+  assert("OptionalMemberExpression", node, opts);
+}
+export function assertOptionalCallExpression(
+  node: Object,
+  opts?: Object = {},
+): void {
+  assert("OptionalCallExpression", node, opts);
+}
 export function assertImport(node: Object, opts?: Object = {}): void {
   assert("Import", node, opts);
 }

packages/babel-types/src/builders/generated/index.js

@@ -596,6 +596,14 @@ export function ClassProperty(...args: Array<any>): Object {
   return builder("ClassProperty", ...args);
 }
 export { ClassProperty as classProperty };
+export function OptionalMemberExpression(...args: Array<any>): Object {
+  return builder("OptionalMemberExpression", ...args);
+}
+export { OptionalMemberExpression as optionalMemberExpression };
+export function OptionalCallExpression(...args: Array<any>): Object {
+  return builder("OptionalCallExpression", ...args);
+}
+export { OptionalCallExpression as optionalCallExpression };
 export function Import(...args: Array<any>): Object {
   return builder("Import", ...args);
 }

packages/babel-types/src/definitions/experimental.js

@@ -54,6 +54,63 @@ defineType("ClassProperty", {
   },
 });
 
+defineType("OptionalMemberExpression", {
+  builder: ["object", "property", "computed", "optional"],
+  visitor: ["object", "property"],
+  aliases: ["Expression"],
+  fields: {
+    object: {
+      validate: assertNodeType("Expression"),
+    },
+    property: {
+      validate: (function() {
+        const normal = assertNodeType("Identifier");
+        const computed = assertNodeType("Expression");
+
+        return function(node, key, val) {
+          const validator = node.computed ? computed : normal;
+          validator(node, key, val);
+        };
+      })(),
+    },
+    computed: {
+      default: false,
+    },
+    optional: {
+      validate: assertValueType("boolean"),
+    },
+  },
+});
+
+defineType("OptionalCallExpression", {
+  visitor: ["callee", "arguments", "typeParameters"],
+  builder: ["callee", "arguments", "optional"],
+  aliases: ["Expression"],
+  fields: {
+    callee: {
+      validate: assertNodeType("Expression"),
+    },
+    arguments: {
+      validate: chain(
+        assertValueType("array"),
+        assertEach(
+          assertNodeType("Expression", "SpreadElement", "JSXNamespacedName"),
+        ),
+      ),
+    },
+    optional: {
+      validate: assertValueType("boolean"),
+    },
+    typeParameters: {
+      validate: assertNodeType(
+        "TypeParameterInstantiation",
+        "TSTypeParameterInstantiation",
+      ),
+      optional: true,
+    },
+  },
+});
+
 defineType("Import", {
   aliases: ["Expression"],
 });

packages/babel-types/src/validators/generated/index.js

@@ -485,6 +485,15 @@ export function isBindExpression(node: Object, opts?: Object): boolean {
 export function isClassProperty(node: Object, opts?: Object): boolean {
   return is("ClassProperty", node, opts);
 }
+export function isOptionalMemberExpression(
+  node: Object,
+  opts?: Object,
+): boolean {
+  return is("OptionalMemberExpression", node, opts);
+}
+export function isOptionalCallExpression(node: Object, opts?: Object): boolean {
+  return is("OptionalCallExpression", node, opts);
+}
 export function isImport(node: Object, opts?: Object): boolean {
   return is("Import", node, opts);
 }

packages/babylon/src/parser/expression.js

@@ -433,13 +433,13 @@ export default class ExpressionParser extends LValParser {
     return base;
   }
 
-  /** @param state Set 'state.stop = true' to indicate that we should stop parsing subscripts. */
+  /** @param state Set 'state.stop = true' to indicate that we should stop parsing subscripts.  'state.optionalChainMember to indicate that the member is currently in OptionalChain'*/
   parseSubscript(
     base: N.Expression,
     startPos: number,
     startLoc: Position,
     noCalls: ?boolean,
-    state: { stop: boolean },
+    state: { stop: boolean, optionalChainMember?: boolean },
   ): N.Expression {
     if (!noCalls && this.eat(tt.doubleColon)) {
       const node = this.startNodeAt(startPos, startLoc);
@@ -454,7 +454,7 @@ export default class ExpressionParser extends LValParser {
       );
     } else if (this.match(tt.questionDot)) {
       this.expectPlugin("optionalChaining");
-
+      state.optionalChainMember = true;
       if (noCalls && this.lookahead().type == tt.parenL) {
         state.stop = true;
         return base;
@@ -469,7 +469,7 @@ export default class ExpressionParser extends LValParser {
         node.computed = true;
         node.optional = true;
         this.expect(tt.bracketR);
-        return this.finishNode(node, "MemberExpression");
+        return this.finishNode(node, "OptionalMemberExpression");
       } else if (this.eat(tt.parenL)) {
         const possibleAsync = this.atPossibleAsync(base);
 
@@ -480,19 +480,23 @@ export default class ExpressionParser extends LValParser {
         );
         node.optional = true;
 
-        return this.finishNode(node, "CallExpression");
+        return this.finishNode(node, "OptionalCallExpression");
       } else {
         node.object = base;
         node.property = this.parseIdentifier(true);
         node.computed = false;
         node.optional = true;
-        return this.finishNode(node, "MemberExpression");
+        return this.finishNode(node, "OptionalMemberExpression");
       }
     } else if (this.eat(tt.dot)) {
       const node = this.startNodeAt(startPos, startLoc);
       node.object = base;
       node.property = this.parseMaybePrivateName();
       node.computed = false;
+      if (state.optionalChainMember) {
+        node.optional = false;
+        return this.finishNode(node, "OptionalMemberExpression");
+      }
       return this.finishNode(node, "MemberExpression");
     } else if (this.eat(tt.bracketL)) {
       const node = this.startNodeAt(startPos, startLoc);
@@ -500,6 +504,10 @@ export default class ExpressionParser extends LValParser {
       node.property = this.parseExpression();
       node.computed = true;
       this.expect(tt.bracketR);
+      if (state.optionalChainMember) {
+        node.optional = false;
+        return this.finishNode(node, "OptionalMemberExpression");
+      }
       return this.finishNode(node, "MemberExpression");
     } else if (!noCalls && this.match(tt.parenL)) {
       const possibleAsync = this.atPossibleAsync(base);
@@ -518,7 +526,11 @@ export default class ExpressionParser extends LValParser {
         possibleAsync,
         refTrailingCommaPos,
       );
-      this.finishCallExpression(node);
+      if (!state.optionalChainMember) {
+        this.finishCallExpression(node);
+      } else {
+        this.finishOptionalCallExpression(node);
+      }
 
       if (possibleAsync && this.shouldParseAsyncArrow()) {
         state.stop = true;
@@ -542,7 +554,14 @@ export default class ExpressionParser extends LValParser {
       const node = this.startNodeAt(startPos, startLoc);
       node.tag = base;
       node.quasi = this.parseTemplate(true);
-      return this.finishNode(node, "TaggedTemplateExpression");
+      if (!state.optionalChainMember) {
+        return this.finishNode(node, "TaggedTemplateExpression");
+      } else {
+        this.raise(
+          startPos,
+          "Tagged Template Literals are not allowed in optionalChain",
+        );
+      }
     } else {
       state.stop = true;
       return base;
@@ -572,6 +591,20 @@ export default class ExpressionParser extends LValParser {
     return this.finishNode(node, "CallExpression");
   }
 
+  finishOptionalCallExpression(node: N.CallExpression): N.CallExpression {
+    if (node.callee.type === "Import") {
+      if (node.arguments.length !== 1) {
+        this.raise(node.start, "import() requires exactly one argument");
+      }
+
+      const importArg = node.arguments[0];
+      if (importArg && importArg.type === "SpreadElement") {
+        this.raise(importArg.start, "... is not allowed in import()");
+      }
+    }
+    return this.finishNode(node, "OptionalCallExpression");
+  }
+
   parseCallExpressionArguments(
     close: TokenType,
     possibleAsyncArrow: boolean,
@@ -1103,7 +1136,21 @@ export default class ExpressionParser extends LValParser {
     }
 
     node.callee = this.parseNoCallExpr();
-    if (this.eat(tt.questionDot)) node.optional = true;
+    if (
+      node.callee.type === "OptionalMemberExpression" ||
+      node.callee.type === "OptionalCallExpression"
+    ) {
+      this.raise(
+        this.state.lastTokEnd,
+        "constructors in/after an Optional Chain are not allowed",
+      );
+    }
+    if (this.eat(tt.questionDot)) {
+      this.raise(
+        this.state.start,
+        "constructors in/after an Optional Chain are not allowed",
+      );
+    }
     this.parseNewArguments(node);
     return this.finishNode(node, "NewExpression");
   }

packages/babylon/src/types.js

@@ -509,6 +509,18 @@ export type MemberExpression = NodeBase & {
   computed: boolean,
 };
 
+export type OptionalMemberExpression = NodeBase & {
+  type: "OptionalMemberExpression",
+  object: Expression | Super,
+  property: Expression,
+  computed: boolean,
+  optional: boolean,
+};
+
+export type OptionalCallExpression = CallOrNewBase & {
+  type: "OptionalCallExpression",
+  optional: boolean,
+};
 export type BindExpression = NodeBase & {
   type: "BindExpression",
   object: $ReadOnlyArray<?Expression>,

packages/babylon/test/fixtures/experimental/optional-chaining/class-contructor-call/input.js

@@ -1,9 +1 @@
-new C?.()
+new C?.b.d()
-
-new C?.(a, b)
-
-new B?.C?.()
-
-new B?.C?.(a, b)
-
-new B?.C

packages/babylon/test/fixtures/experimental/optional-chaining/class-contructor-call/options.json

@@ -1,3 +1,4 @@
 {
-  "plugins": ["optionalChaining"]
+  "plugins": ["optionalChaining"],
+  "throws": "constructors in/after an Optional Chain are not allowed (1:10)"
 }

packages/babylon/test/fixtures/experimental/optional-chaining/class-contructor-call/output.json

@@ -1,450 +0,0 @@
-{
-  "type": "File",
-  "start": 0,
-  "end": 66,
-  "loc": {
-    "start": {
-      "line": 1,
-      "column": 0
-    },
-    "end": {
-      "line": 9,
-      "column": 8
-    }
-  },
-  "program": {
-    "type": "Program",
-    "start": 0,
-    "end": 66,
-    "loc": {
-      "start": {
-        "line": 1,
-        "column": 0
-      },
-      "end": {
-        "line": 9,
-        "column": 8
-      }
-    },
-    "sourceType": "script",
-    "body": [
-      {
-        "type": "ExpressionStatement",
-        "start": 0,
-        "end": 9,
-        "loc": {
-          "start": {
-            "line": 1,
-            "column": 0
-          },
-          "end": {
-            "line": 1,
-            "column": 9
-          }
-        },
-        "expression": {
-          "type": "NewExpression",
-          "start": 0,
-          "end": 9,
-          "loc": {
-            "start": {
-              "line": 1,
-              "column": 0
-            },
-            "end": {
-              "line": 1,
-              "column": 9
-            }
-          },
-          "callee": {
-            "type": "Identifier",
-            "start": 4,
-            "end": 5,
-            "loc": {
-              "start": {
-                "line": 1,
-                "column": 4
-              },
-              "end": {
-                "line": 1,
-                "column": 5
-              },
-              "identifierName": "C"
-            },
-            "name": "C"
-          },
-          "optional": true,
-          "arguments": []
-        }
-      },
-      {
-        "type": "ExpressionStatement",
-        "start": 11,
-        "end": 24,
-        "loc": {
-          "start": {
-            "line": 3,
-            "column": 0
-          },
-          "end": {
-            "line": 3,
-            "column": 13
-          }
-        },
-        "expression": {
-          "type": "NewExpression",
-          "start": 11,
-          "end": 24,
-          "loc": {
-            "start": {
-              "line": 3,
-              "column": 0
-            },
-            "end": {
-              "line": 3,
-              "column": 13
-            }
-          },
-          "callee": {
-            "type": "Identifier",
-            "start": 15,
-            "end": 16,
-            "loc": {
-              "start": {
-                "line": 3,
-                "column": 4
-              },
-              "end": {
-                "line": 3,
-                "column": 5
-              },
-              "identifierName": "C"
-            },
-            "name": "C"
-          },
-          "optional": true,
-          "arguments": [
-            {
-              "type": "Identifier",
-              "start": 19,
-              "end": 20,
-              "loc": {
-                "start": {
-                  "line": 3,
-                  "column": 8
-                },
-                "end": {
-                  "line": 3,
-                  "column": 9
-                },
-                "identifierName": "a"
-              },
-              "name": "a"
-            },
-            {
-              "type": "Identifier",
-              "start": 22,
-              "end": 23,
-              "loc": {
-                "start": {
-                  "line": 3,
-                  "column": 11
-                },
-                "end": {
-                  "line": 3,
-                  "column": 12
-                },
-                "identifierName": "b"
-              },
-              "name": "b"
-            }
-          ]
-        }
-      },
-      {
-        "type": "ExpressionStatement",
-        "start": 26,
-        "end": 38,
-        "loc": {
-          "start": {
-            "line": 5,
-            "column": 0
-          },
-          "end": {
-            "line": 5,
-            "column": 12
-          }
-        },
-        "expression": {
-          "type": "NewExpression",
-          "start": 26,
-          "end": 38,
-          "loc": {
-            "start": {
-              "line": 5,
-              "column": 0
-            },
-            "end": {
-              "line": 5,
-              "column": 12
-            }
-          },
-          "callee": {
-            "type": "MemberExpression",
-            "start": 30,
-            "end": 34,
-            "loc": {
-              "start": {
-                "line": 5,
-                "column": 4
-              },
-              "end": {
-                "line": 5,
-                "column": 8
-              }
-            },
-            "object": {
-              "type": "Identifier",
-              "start": 30,
-              "end": 31,
-              "loc": {
-                "start": {
-                  "line": 5,
-                  "column": 4
-                },
-                "end": {
-                  "line": 5,
-                  "column": 5
-                },
-                "identifierName": "B"
-              },
-              "name": "B"
-            },
-            "property": {
-              "type": "Identifier",
-              "start": 33,
-              "end": 34,
-              "loc": {
-                "start": {
-                  "line": 5,
-                  "column": 7
-                },
-                "end": {
-                  "line": 5,
-                  "column": 8
-                },
-                "identifierName": "C"
-              },
-              "name": "C"
-            },
-            "computed": false,
-            "optional": true
-          },
-          "optional": true,
-          "arguments": []
-        }
-      },
-      {
-        "type": "ExpressionStatement",
-        "start": 40,
-        "end": 56,
-        "loc": {
-          "start": {
-            "line": 7,
-            "column": 0
-          },
-          "end": {
-            "line": 7,
-            "column": 16
-          }
-        },
-        "expression": {
-          "type": "NewExpression",
-          "start": 40,
-          "end": 56,
-          "loc": {
-            "start": {
-              "line": 7,
-              "column": 0
-            },
-            "end": {
-              "line": 7,
-              "column": 16
-            }
-          },
-          "callee": {
-            "type": "MemberExpression",
-            "start": 44,
-            "end": 48,
-            "loc": {
-              "start": {
-                "line": 7,
-                "column": 4
-              },
-              "end": {
-                "line": 7,
-                "column": 8
-              }
-            },
-            "object": {
-              "type": "Identifier",
-              "start": 44,
-              "end": 45,
-              "loc": {
-                "start": {
-                  "line": 7,
-                  "column": 4
-                },
-                "end": {
-                  "line": 7,
-                  "column": 5
-                },
-                "identifierName": "B"
-              },
-              "name": "B"
-            },
-            "property": {
-              "type": "Identifier",
-              "start": 47,
-              "end": 48,
-              "loc": {
-                "start": {
-                  "line": 7,
-                  "column": 7
-                },
-                "end": {
-                  "line": 7,
-                  "column": 8
-                },
-                "identifierName": "C"
-              },
-              "name": "C"
-            },
-            "computed": false,
-            "optional": true
-          },
-          "optional": true,
-          "arguments": [
-            {
-              "type": "Identifier",
-              "start": 51,
-              "end": 52,
-              "loc": {
-                "start": {
-                  "line": 7,
-                  "column": 11
-                },
-                "end": {
-                  "line": 7,
-                  "column": 12
-                },
-                "identifierName": "a"
-              },
-              "name": "a"
-            },
-            {
-              "type": "Identifier",
-              "start": 54,
-              "end": 55,
-              "loc": {
-                "start": {
-                  "line": 7,
-                  "column": 14
-                },
-                "end": {
-                  "line": 7,
-                  "column": 15
-                },
-                "identifierName": "b"
-              },
-              "name": "b"
-            }
-          ]
-        }
-      },
-      {
-        "type": "ExpressionStatement",
-        "start": 58,
-        "end": 66,
-        "loc": {
-          "start": {
-            "line": 9,
-            "column": 0
-          },
-          "end": {
-            "line": 9,
-            "column": 8
-          }
-        },
-        "expression": {
-          "type": "NewExpression",
-          "start": 58,
-          "end": 66,
-          "loc": {
-            "start": {
-              "line": 9,
-              "column": 0
-            },
-            "end": {
-              "line": 9,
-              "column": 8
-            }
-          },
-          "callee": {
-            "type": "MemberExpression",
-            "start": 62,
-            "end": 66,
-            "loc": {
-              "start": {
-                "line": 9,
-                "column": 4
-              },
-              "end": {
-                "line": 9,
-                "column": 8
-              }
-            },
-            "object": {
-              "type": "Identifier",
-              "start": 62,
-              "end": 63,
-              "loc": {
-                "start": {
-                  "line": 9,
-                  "column": 4
-                },
-                "end": {
-                  "line": 9,
-                  "column": 5
-                },
-                "identifierName": "B"
-              },
-              "name": "B"
-            },
-            "property": {
-              "type": "Identifier",
-              "start": 65,
-              "end": 66,
-              "loc": {
-                "start": {
-                  "line": 9,
-                  "column": 7
-                },
-                "end": {
-                  "line": 9,
-                  "column": 8
-                },
-                "identifierName": "C"
-              },
-              "name": "C"
-            },
-            "computed": false,
-            "optional": true
-          },
-          "arguments": []
-        }
-      }
-    ],
-    "directives": []
-  }
-}

packages/babylon/test/fixtures/experimental/optional-chaining/function-call/input.js

@@ -5,3 +5,5 @@ func?.(a, b)
 a?.func?.()
 
 a?.func?.(a, b)
+
+a.func?.()

packages/babylon/test/fixtures/experimental/optional-chaining/function-call/output.json

@@ -1,29 +1,29 @@
 {
   "type": "File",
   "start": 0,
-  "end": 52,
+  "end": 64,
   "loc": {
     "start": {
       "line": 1,
       "column": 0
     },
     "end": {
-      "line": 7,
+      "line": 9,
-      "column": 15
+      "column": 10
     }
   },
   "program": {
     "type": "Program",
     "start": 0,
-    "end": 52,
+    "end": 64,
     "loc": {
       "start": {
         "line": 1,
         "column": 0
       },
       "end": {
-        "line": 7,
+        "line": 9,
-        "column": 15
+        "column": 10
       }
     },
     "sourceType": "script",
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "CallExpression",
+          "type": "OptionalCallExpression",
           "start": 0,
           "end": 8,
           "loc": {
@@ -92,7 +92,7 @@
           }
         },
         "expression": {
-          "type": "CallExpression",
+          "type": "OptionalCallExpression",
           "start": 10,
           "end": 22,
           "loc": {
@@ -176,7 +176,7 @@
           }
         },
         "expression": {
-          "type": "CallExpression",
+          "type": "OptionalCallExpression",
           "start": 24,
           "end": 35,
           "loc": {
@@ -190,7 +190,7 @@
             }
           },
           "callee": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 24,
             "end": 31,
             "loc": {
@@ -259,7 +259,7 @@
           }
         },
         "expression": {
-          "type": "CallExpression",
+          "type": "OptionalCallExpression",
           "start": 37,
           "end": 52,
           "loc": {
@@ -273,7 +273,7 @@
             }
           },
           "callee": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 37,
             "end": 44,
             "loc": {
@@ -361,6 +361,88 @@
           ],
           "optional": true
         }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 54,
+        "end": 64,
+        "loc": {
+          "start": {
+            "line": 9,
+            "column": 0
+          },
+          "end": {
+            "line": 9,
+            "column": 10
+          }
+        },
+        "expression": {
+          "type": "OptionalCallExpression",
+          "start": 54,
+          "end": 64,
+          "loc": {
+            "start": {
+              "line": 9,
+              "column": 0
+            },
+            "end": {
+              "line": 9,
+              "column": 10
+            }
+          },
+          "callee": {
+            "type": "MemberExpression",
+            "start": 54,
+            "end": 60,
+            "loc": {
+              "start": {
+                "line": 9,
+                "column": 0
+              },
+              "end": {
+                "line": 9,
+                "column": 6
+              }
+            },
+            "object": {
+              "type": "Identifier",
+              "start": 54,
+              "end": 55,
+              "loc": {
+                "start": {
+                  "line": 9,
+                  "column": 0
+                },
+                "end": {
+                  "line": 9,
+                  "column": 1
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 56,
+              "end": 60,
+              "loc": {
+                "start": {
+                  "line": 9,
+                  "column": 2
+                },
+                "end": {
+                  "line": 9,
+                  "column": 6
+                },
+                "identifierName": "func"
+              },
+              "name": "func"
+            },
+            "computed": false
+          },
+          "arguments": [],
+          "optional": true
+        }
       }
     ],
     "directives": []

packages/babylon/test/fixtures/experimental/optional-chaining/member-access-bracket/input.js

@@ -5,3 +5,7 @@ obj?.[expr]?.[other]
 obj?.[true]
 
 obj?.[true]?.[true]
+
+obj.a?.[expr]
+
+obj.a?.[true]

packages/babylon/test/fixtures/experimental/optional-chaining/member-access-bracket/output.json

@@ -1,29 +1,29 @@
 {
   "type": "File",
   "start": 0,
-  "end": 67,
+  "end": 97,
   "loc": {
     "start": {
       "line": 1,
       "column": 0
     },
     "end": {
-      "line": 7,
+      "line": 11,
-      "column": 19
+      "column": 13
     }
   },
   "program": {
     "type": "Program",
     "start": 0,
-    "end": 67,
+    "end": 97,
     "loc": {
       "start": {
         "line": 1,
         "column": 0
       },
       "end": {
-        "line": 7,
+        "line": 11,
-        "column": 19
+        "column": 13
       }
     },
     "sourceType": "script",
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 0,
           "end": 11,
           "loc": {
@@ -109,7 +109,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 13,
           "end": 33,
           "loc": {
@@ -123,7 +123,7 @@
             }
           },
           "object": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 13,
             "end": 24,
             "loc": {
@@ -209,7 +209,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 35,
           "end": 46,
           "loc": {
@@ -274,7 +274,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 48,
           "end": 67,
           "loc": {
@@ -288,7 +288,7 @@
             }
           },
           "object": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 48,
             "end": 59,
             "loc": {
@@ -356,6 +356,203 @@
           "computed": true,
           "optional": true
         }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 69,
+        "end": 82,
+        "loc": {
+          "start": {
+            "line": 9,
+            "column": 0
+          },
+          "end": {
+            "line": 9,
+            "column": 13
+          }
+        },
+        "expression": {
+          "type": "OptionalMemberExpression",
+          "start": 69,
+          "end": 82,
+          "loc": {
+            "start": {
+              "line": 9,
+              "column": 0
+            },
+            "end": {
+              "line": 9,
+              "column": 13
+            }
+          },
+          "object": {
+            "type": "MemberExpression",
+            "start": 69,
+            "end": 74,
+            "loc": {
+              "start": {
+                "line": 9,
+                "column": 0
+              },
+              "end": {
+                "line": 9,
+                "column": 5
+              }
+            },
+            "object": {
+              "type": "Identifier",
+              "start": 69,
+              "end": 72,
+              "loc": {
+                "start": {
+                  "line": 9,
+                  "column": 0
+                },
+                "end": {
+                  "line": 9,
+                  "column": 3
+                },
+                "identifierName": "obj"
+              },
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 73,
+              "end": 74,
+              "loc": {
+                "start": {
+                  "line": 9,
+                  "column": 4
+                },
+                "end": {
+                  "line": 9,
+                  "column": 5
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            },
+            "computed": false
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 77,
+            "end": 81,
+            "loc": {
+              "start": {
+                "line": 9,
+                "column": 8
+              },
+              "end": {
+                "line": 9,
+                "column": 12
+              },
+              "identifierName": "expr"
+            },
+            "name": "expr"
+          },
+          "computed": true,
+          "optional": true
+        }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 84,
+        "end": 97,
+        "loc": {
+          "start": {
+            "line": 11,
+            "column": 0
+          },
+          "end": {
+            "line": 11,
+            "column": 13
+          }
+        },
+        "expression": {
+          "type": "OptionalMemberExpression",
+          "start": 84,
+          "end": 97,
+          "loc": {
+            "start": {
+              "line": 11,
+              "column": 0
+            },
+            "end": {
+              "line": 11,
+              "column": 13
+            }
+          },
+          "object": {
+            "type": "MemberExpression",
+            "start": 84,
+            "end": 89,
+            "loc": {
+              "start": {
+                "line": 11,
+                "column": 0
+              },
+              "end": {
+                "line": 11,
+                "column": 5
+              }
+            },
+            "object": {
+              "type": "Identifier",
+              "start": 84,
+              "end": 87,
+              "loc": {
+                "start": {
+                  "line": 11,
+                  "column": 0
+                },
+                "end": {
+                  "line": 11,
+                  "column": 3
+                },
+                "identifierName": "obj"
+              },
+              "name": "obj"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 88,
+              "end": 89,
+              "loc": {
+                "start": {
+                  "line": 11,
+                  "column": 4
+                },
+                "end": {
+                  "line": 11,
+                  "column": 5
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            },
+            "computed": false
+          },
+          "property": {
+            "type": "BooleanLiteral",
+            "start": 92,
+            "end": 96,
+            "loc": {
+              "start": {
+                "line": 11,
+                "column": 8
+              },
+              "end": {
+                "line": 11,
+                "column": 12
+              }
+            },
+            "value": true
+          },
+          "computed": true,
+          "optional": true
+        }
       }
     ],
     "directives": []

packages/babylon/test/fixtures/experimental/optional-chaining/member-access/input.js

@@ -1,3 +1,5 @@
 foo?.bar
 
 foo?.bar?.baz
+
+foo.bar?.baz

packages/babylon/test/fixtures/experimental/optional-chaining/member-access/output.json

@@ -1,29 +1,29 @@
 {
   "type": "File",
   "start": 0,
-  "end": 23,
+  "end": 37,
   "loc": {
     "start": {
       "line": 1,
       "column": 0
     },
     "end": {
-      "line": 3,
+      "line": 5,
-      "column": 13
+      "column": 12
     }
   },
   "program": {
     "type": "Program",
     "start": 0,
-    "end": 23,
+    "end": 37,
     "loc": {
       "start": {
         "line": 1,
         "column": 0
       },
       "end": {
-        "line": 3,
+        "line": 5,
-        "column": 13
+        "column": 12
       }
     },
     "sourceType": "script",
@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 0,
           "end": 8,
           "loc": {
@@ -109,7 +109,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 10,
           "end": 23,
           "loc": {
@@ -123,7 +123,7 @@
             }
           },
           "object": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 10,
             "end": 18,
             "loc": {
@@ -193,6 +193,105 @@
           "computed": false,
           "optional": true
         }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 25,
+        "end": 37,
+        "loc": {
+          "start": {
+            "line": 5,
+            "column": 0
+          },
+          "end": {
+            "line": 5,
+            "column": 12
+          }
+        },
+        "expression": {
+          "type": "OptionalMemberExpression",
+          "start": 25,
+          "end": 37,
+          "loc": {
+            "start": {
+              "line": 5,
+              "column": 0
+            },
+            "end": {
+              "line": 5,
+              "column": 12
+            }
+          },
+          "object": {
+            "type": "MemberExpression",
+            "start": 25,
+            "end": 32,
+            "loc": {
+              "start": {
+                "line": 5,
+                "column": 0
+              },
+              "end": {
+                "line": 5,
+                "column": 7
+              }
+            },
+            "object": {
+              "type": "Identifier",
+              "start": 25,
+              "end": 28,
+              "loc": {
+                "start": {
+                  "line": 5,
+                  "column": 0
+                },
+                "end": {
+                  "line": 5,
+                  "column": 3
+                },
+                "identifierName": "foo"
+              },
+              "name": "foo"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 29,
+              "end": 32,
+              "loc": {
+                "start": {
+                  "line": 5,
+                  "column": 4
+                },
+                "end": {
+                  "line": 5,
+                  "column": 7
+                },
+                "identifierName": "bar"
+              },
+              "name": "bar"
+            },
+            "computed": false
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 34,
+            "end": 37,
+            "loc": {
+              "start": {
+                "line": 5,
+                "column": 9
+              },
+              "end": {
+                "line": 5,
+                "column": 12
+              },
+              "identifierName": "baz"
+            },
+            "name": "baz"
+          },
+          "computed": false,
+          "optional": true
+        }
       }
     ],
     "directives": []

packages/babylon/test/fixtures/experimental/optional-chaining/optioanl-chain-expression/input.js

@@ -0,0 +1 @@
+a.b?.c()

packages/babylon/test/fixtures/experimental/optional-chaining/optioanl-chain-expression/options.json

@@ -0,0 +1,3 @@
+{
+    "plugins": ["optionalChaining"]
+}

packages/babylon/test/fixtures/experimental/optional-chaining/optioanl-chain-expression/output.json

@@ -0,0 +1,149 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 8,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 8
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 8,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 8
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 8,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 8
+          }
+        },
+        "expression": {
+          "type": "OptionalCallExpression",
+          "start": 0,
+          "end": 8,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 8
+            }
+          },
+          "callee": {
+            "type": "OptionalMemberExpression",
+            "start": 0,
+            "end": 6,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 0
+              },
+              "end": {
+                "line": 1,
+                "column": 6
+              }
+            },
+            "object": {
+              "type": "MemberExpression",
+              "start": 0,
+              "end": 3,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 0
+                },
+                "end": {
+                  "line": 1,
+                  "column": 3
+                }
+              },
+              "object": {
+                "type": "Identifier",
+                "start": 0,
+                "end": 1,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 0
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 1
+                  },
+                  "identifierName": "a"
+                },
+                "name": "a"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 2,
+                "end": 3,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 2
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 3
+                  },
+                  "identifierName": "b"
+                },
+                "name": "b"
+              },
+              "computed": false
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 5,
+              "end": 6,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 5
+                },
+                "end": {
+                  "line": 1,
+                  "column": 6
+                },
+                "identifierName": "c"
+              },
+              "name": "c"
+            },
+            "computed": false,
+            "optional": true
+          },
+          "arguments": []
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babylon/test/fixtures/experimental/optional-chaining/optional-constructor/input.js

@@ -0,0 +1 @@
+new a?.();

packages/babylon/test/fixtures/experimental/optional-chaining/optional-constructor/options.json

@@ -0,0 +1,4 @@
+{
+    "plugins": ["optionalChaining"],
+    "throws": "constructors in/after an Optional Chain are not allowed (1:7)"
+  }

packages/babylon/test/fixtures/experimental/optional-chaining/optional-tagged-template-literals/input.js

@@ -0,0 +1 @@
+a?.b`foo`

packages/babylon/test/fixtures/experimental/optional-chaining/optional-tagged-template-literals/options.json

@@ -0,0 +1,4 @@
+{
+    "plugins" : ["optionalChaining"],
+    "throws" : "Tagged Template Literals are not allowed in optionalChain (1:0)"
+}

packages/babylon/test/fixtures/experimental/optional-chaining/parenthised-chain/input.js

@@ -0,0 +1,5 @@
+(a?.b).c;
+
+(a?.b).c();
+
+(a?.b)?.c.d?.e;

packages/babylon/test/fixtures/experimental/optional-chaining/parenthised-chain/options.json

@@ -0,0 +1,3 @@
+{
+    "plugins": ["optionalChaining"]
+}

packages/babylon/test/fixtures/experimental/optional-chaining/parenthised-chain/output.json

@@ -0,0 +1,428 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 39,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 5,
+      "column": 15
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 39,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 5,
+        "column": 15
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 9,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 9
+          }
+        },
+        "expression": {
+          "type": "MemberExpression",
+          "start": 0,
+          "end": 8,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 8
+            }
+          },
+          "object": {
+            "type": "OptionalMemberExpression",
+            "start": 1,
+            "end": 5,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 1
+              },
+              "end": {
+                "line": 1,
+                "column": 5
+              }
+            },
+            "object": {
+              "type": "Identifier",
+              "start": 1,
+              "end": 2,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 1
+                },
+                "end": {
+                  "line": 1,
+                  "column": 2
+                },
+                "identifierName": "a"
+              },
+              "name": "a"
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 4,
+              "end": 5,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 4
+                },
+                "end": {
+                  "line": 1,
+                  "column": 5
+                },
+                "identifierName": "b"
+              },
+              "name": "b"
+            },
+            "computed": false,
+            "optional": true,
+            "extra": {
+              "parenthesized": true,
+              "parenStart": 0
+            }
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 7,
+            "end": 8,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 7
+              },
+              "end": {
+                "line": 1,
+                "column": 8
+              },
+              "identifierName": "c"
+            },
+            "name": "c"
+          },
+          "computed": false
+        }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 11,
+        "end": 22,
+        "loc": {
+          "start": {
+            "line": 3,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 11
+          }
+        },
+        "expression": {
+          "type": "CallExpression",
+          "start": 11,
+          "end": 21,
+          "loc": {
+            "start": {
+              "line": 3,
+              "column": 0
+            },
+            "end": {
+              "line": 3,
+              "column": 10
+            }
+          },
+          "callee": {
+            "type": "MemberExpression",
+            "start": 11,
+            "end": 19,
+            "loc": {
+              "start": {
+                "line": 3,
+                "column": 0
+              },
+              "end": {
+                "line": 3,
+                "column": 8
+              }
+            },
+            "object": {
+              "type": "OptionalMemberExpression",
+              "start": 12,
+              "end": 16,
+              "loc": {
+                "start": {
+                  "line": 3,
+                  "column": 1
+                },
+                "end": {
+                  "line": 3,
+                  "column": 5
+                }
+              },
+              "object": {
+                "type": "Identifier",
+                "start": 12,
+                "end": 13,
+                "loc": {
+                  "start": {
+                    "line": 3,
+                    "column": 1
+                  },
+                  "end": {
+                    "line": 3,
+                    "column": 2
+                  },
+                  "identifierName": "a"
+                },
+                "name": "a"
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 15,
+                "end": 16,
+                "loc": {
+                  "start": {
+                    "line": 3,
+                    "column": 4
+                  },
+                  "end": {
+                    "line": 3,
+                    "column": 5
+                  },
+                  "identifierName": "b"
+                },
+                "name": "b"
+              },
+              "computed": false,
+              "optional": true,
+              "extra": {
+                "parenthesized": true,
+                "parenStart": 11
+              }
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 18,
+              "end": 19,
+              "loc": {
+                "start": {
+                  "line": 3,
+                  "column": 7
+                },
+                "end": {
+                  "line": 3,
+                  "column": 8
+                },
+                "identifierName": "c"
+              },
+              "name": "c"
+            },
+            "computed": false
+          },
+          "arguments": []
+        }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 24,
+        "end": 39,
+        "loc": {
+          "start": {
+            "line": 5,
+            "column": 0
+          },
+          "end": {
+            "line": 5,
+            "column": 15
+          }
+        },
+        "expression": {
+          "type": "OptionalMemberExpression",
+          "start": 24,
+          "end": 38,
+          "loc": {
+            "start": {
+              "line": 5,
+              "column": 0
+            },
+            "end": {
+              "line": 5,
+              "column": 14
+            }
+          },
+          "object": {
+            "type": "OptionalMemberExpression",
+            "start": 24,
+            "end": 35,
+            "loc": {
+              "start": {
+                "line": 5,
+                "column": 0
+              },
+              "end": {
+                "line": 5,
+                "column": 11
+              }
+            },
+            "object": {
+              "type": "OptionalMemberExpression",
+              "start": 24,
+              "end": 33,
+              "loc": {
+                "start": {
+                  "line": 5,
+                  "column": 0
+                },
+                "end": {
+                  "line": 5,
+                  "column": 9
+                }
+              },
+              "object": {
+                "type": "OptionalMemberExpression",
+                "start": 25,
+                "end": 29,
+                "loc": {
+                  "start": {
+                    "line": 5,
+                    "column": 1
+                  },
+                  "end": {
+                    "line": 5,
+                    "column": 5
+                  }
+                },
+                "object": {
+                  "type": "Identifier",
+                  "start": 25,
+                  "end": 26,
+                  "loc": {
+                    "start": {
+                      "line": 5,
+                      "column": 1
+                    },
+                    "end": {
+                      "line": 5,
+                      "column": 2
+                    },
+                    "identifierName": "a"
+                  },
+                  "name": "a"
+                },
+                "property": {
+                  "type": "Identifier",
+                  "start": 28,
+                  "end": 29,
+                  "loc": {
+                    "start": {
+                      "line": 5,
+                      "column": 4
+                    },
+                    "end": {
+                      "line": 5,
+                      "column": 5
+                    },
+                    "identifierName": "b"
+                  },
+                  "name": "b"
+                },
+                "computed": false,
+                "optional": true,
+                "extra": {
+                  "parenthesized": true,
+                  "parenStart": 24
+                }
+              },
+              "property": {
+                "type": "Identifier",
+                "start": 32,
+                "end": 33,
+                "loc": {
+                  "start": {
+                    "line": 5,
+                    "column": 8
+                  },
+                  "end": {
+                    "line": 5,
+                    "column": 9
+                  },
+                  "identifierName": "c"
+                },
+                "name": "c"
+              },
+              "computed": false,
+              "optional": true
+            },
+            "property": {
+              "type": "Identifier",
+              "start": 34,
+              "end": 35,
+              "loc": {
+                "start": {
+                  "line": 5,
+                  "column": 10
+                },
+                "end": {
+                  "line": 5,
+                  "column": 11
+                },
+                "identifierName": "d"
+              },
+              "name": "d"
+            },
+            "computed": false,
+            "optional": false
+          },
+          "property": {
+            "type": "Identifier",
+            "start": 37,
+            "end": 38,
+            "loc": {
+              "start": {
+                "line": 5,
+                "column": 13
+              },
+              "end": {
+                "line": 5,
+                "column": 14
+              },
+              "identifierName": "e"
+            },
+            "name": "e"
+          },
+          "computed": false,
+          "optional": true
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babylon/test/fixtures/experimental/optional-chaining/separated-chaining/output.json

@@ -43,7 +43,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 0,
           "end": 13,
           "loc": {
@@ -57,7 +57,7 @@
             }
           },
           "object": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 0,
             "end": 10,
             "loc": {
@@ -71,7 +71,7 @@
               }
             },
             "object": {
-              "type": "MemberExpression",
+              "type": "OptionalMemberExpression",
               "start": 0,
               "end": 8,
               "loc": {
@@ -85,7 +85,7 @@
                 }
               },
               "object": {
-                "type": "MemberExpression",
+                "type": "OptionalMemberExpression",
                 "start": 0,
                 "end": 6,
                 "loc": {
@@ -99,7 +99,7 @@
                   }
                 },
                 "object": {
-                  "type": "MemberExpression",
+                  "type": "OptionalMemberExpression",
                   "start": 0,
                   "end": 4,
                   "loc": {
@@ -166,7 +166,8 @@
                   },
                   "name": "c"
                 },
-                "computed": false
+                "computed": false,
+                "optional": false
               },
               "property": {
                 "type": "Identifier",
@@ -185,7 +186,8 @@
                 },
                 "name": "d"
               },
-              "computed": false
+              "computed": false,
+              "optional": false
             },
             "property": {
               "type": "Identifier",
@@ -204,7 +206,8 @@
               },
               "name": "e"
             },
-            "computed": false
+            "computed": false,
+            "optional": false
           },
           "property": {
             "type": "Identifier",
@@ -242,7 +245,7 @@
           }
         },
         "expression": {
-          "type": "MemberExpression",
+          "type": "OptionalMemberExpression",
           "start": 15,
           "end": 27,
           "loc": {
@@ -256,7 +259,7 @@
             }
           },
           "object": {
-            "type": "MemberExpression",
+            "type": "OptionalMemberExpression",
             "start": 15,
             "end": 25,
             "loc": {
@@ -270,7 +273,7 @@
               }
             },
             "object": {
-              "type": "MemberExpression",
+              "type": "OptionalMemberExpression",
               "start": 15,
               "end": 23,
               "loc": {
@@ -403,7 +406,8 @@
               },
               "name": "e"
             },
-            "computed": false
+            "computed": false,
+            "optional": false
           },
           "property": {
             "type": "Identifier",
@@ -422,7 +426,8 @@
             },
             "name": "f"
           },
-          "computed": false
+          "computed": false,
+          "optional": false
         }
       }
     ],