[ts] Disallow property access after instantiation expression

packages/babel-parser/src/plugins/typescript/index.js

@@ -167,6 +167,10 @@ const TSErrors = ParseErrorEnum`typescript`(_ => ({
     ({ orderedModifiers }) =>
       `'${orderedModifiers[0]}' modifier must precede '${orderedModifiers[1]}' modifier.`,
   ),
+  InvalidPropertyAccessAfterInstantiationExpression: _(
+    "Invalid property access after an instantiation expression. " +
+      "You can either wrap the instantiation expression in parentheses, or delete the type arguments.",
+  ),
   InvalidTupleMemberLabel: _(
     "Tuple members must be labeled with a simple identifier.",
   ),
@@ -2488,7 +2492,20 @@ export default (superClass: Class<Parser>): Class<Parser> =>
           this.unexpected(missingParenErrorLoc, tt.parenL);
         }
 
-        if (result) return result;
+        if (result) {
+          if (
+            result.type === "TSInstantiationExpression" &&
+            (this.match(tt.dot) ||
+              (this.match(tt.questionDot) &&
+                this.lookaheadCharCode() !== charCodes.leftParenthesis))
+          ) {
+            this.raise(
+              TSErrors.InvalidPropertyAccessAfterInstantiationExpression,
+              { at: this.state.startLoc },
+            );
+          }
+          return result;
+        }
       }
 
       return super.parseSubscript(base, startPos, startLoc, noCalls, state);

packages/babel-parser/test/fixtures/typescript/type-arguments/instantiation-expression-optional-chain/input.ts

@@ -0,0 +1,2 @@
+a?.b<c>;
+a?.b<c>();

packages/babel-parser/test/fixtures/typescript/type-arguments/instantiation-expression-optional-chain/output.json

@@ -0,0 +1,93 @@
+{
+  "type": "File",
+  "start":0,"end":19,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":2,"column":10,"index":19}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":19,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":2,"column":10,"index":19}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start":0,"end":8,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":8,"index":8}},
+        "expression": {
+          "type": "TSInstantiationExpression",
+          "start":0,"end":7,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":7,"index":7}},
+          "expression": {
+            "type": "OptionalMemberExpression",
+            "start":0,"end":4,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":4,"index":4}},
+            "object": {
+              "type": "Identifier",
+              "start":0,"end":1,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":1,"index":1},"identifierName":"a"},
+              "name": "a"
+            },
+            "computed": false,
+            "property": {
+              "type": "Identifier",
+              "start":3,"end":4,"loc":{"start":{"line":1,"column":3,"index":3},"end":{"line":1,"column":4,"index":4},"identifierName":"b"},
+              "name": "b"
+            },
+            "optional": true
+          },
+          "typeParameters": {
+            "type": "TSTypeParameterInstantiation",
+            "start":4,"end":7,"loc":{"start":{"line":1,"column":4,"index":4},"end":{"line":1,"column":7,"index":7}},
+            "params": [
+              {
+                "type": "TSTypeReference",
+                "start":5,"end":6,"loc":{"start":{"line":1,"column":5,"index":5},"end":{"line":1,"column":6,"index":6}},
+                "typeName": {
+                  "type": "Identifier",
+                  "start":5,"end":6,"loc":{"start":{"line":1,"column":5,"index":5},"end":{"line":1,"column":6,"index":6},"identifierName":"c"},
+                  "name": "c"
+                }
+              }
+            ]
+          }
+        }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start":9,"end":19,"loc":{"start":{"line":2,"column":0,"index":9},"end":{"line":2,"column":10,"index":19}},
+        "expression": {
+          "type": "OptionalCallExpression",
+          "start":9,"end":18,"loc":{"start":{"line":2,"column":0,"index":9},"end":{"line":2,"column":9,"index":18}},
+          "callee": {
+            "type": "OptionalMemberExpression",
+            "start":9,"end":13,"loc":{"start":{"line":2,"column":0,"index":9},"end":{"line":2,"column":4,"index":13}},
+            "object": {
+              "type": "Identifier",
+              "start":9,"end":10,"loc":{"start":{"line":2,"column":0,"index":9},"end":{"line":2,"column":1,"index":10},"identifierName":"a"},
+              "name": "a"
+            },
+            "computed": false,
+            "property": {
+              "type": "Identifier",
+              "start":12,"end":13,"loc":{"start":{"line":2,"column":3,"index":12},"end":{"line":2,"column":4,"index":13},"identifierName":"b"},
+              "name": "b"
+            },
+            "optional": true
+          },
+          "arguments": [],
+          "typeParameters": {
+            "type": "TSTypeParameterInstantiation",
+            "start":13,"end":16,"loc":{"start":{"line":2,"column":4,"index":13},"end":{"line":2,"column":7,"index":16}},
+            "params": [
+              {
+                "type": "TSTypeReference",
+                "start":14,"end":15,"loc":{"start":{"line":2,"column":5,"index":14},"end":{"line":2,"column":6,"index":15}},
+                "typeName": {
+                  "type": "Identifier",
+                  "start":14,"end":15,"loc":{"start":{"line":2,"column":5,"index":14},"end":{"line":2,"column":6,"index":15},"identifierName":"c"},
+                  "name": "c"
+                }
+              }
+            ]
+          },
+          "optional": false
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/typescript/type-arguments/instantiation-expression-property-access/input.ts

@@ -0,0 +1,13 @@
+// invalid
+a<b>.c;
+a<b>?.c;
+a<b>?.[c];
+
+// valid
+a<b>?.(c);
+(a<b>).c;
+(a<b>)?.c;
+(a<b>)?.[c];
+
+// longer, invalid
+a?.b<c>.d