Merge pull request #254 from HerringtonDarkholme/fix-conditional

fix: conditional_type should be right-associative

Author: amaanq

common/corpus/types.txt

@@ -1179,23 +1179,23 @@ type T<X> = T extends { x: infer X extends number } ? X : never;
           (identifier)
           (type_annotation (type_identifier))))
       (conditional_type
+        (type_identifier)
+        (type_identifier)
+        (type_identifier)
         (conditional_type
           (type_identifier)
+          (function_type
+            (formal_parameters
+              (required_parameter
+                (identifier)
+                (type_annotation (type_identifier))))
+            (conditional_type
+              (type_identifier)
+              (type_identifier)
+              (type_identifier)
+              (type_identifier)))
           (type_identifier)
-          (type_identifier)
-          (type_identifier))
-        (function_type
-          (formal_parameters
-            (required_parameter
-              (identifier)
-              (type_annotation (type_identifier))))
-          (conditional_type
-            (type_identifier)
-            (type_identifier)
-            (type_identifier)
-            (type_identifier)))
-        (type_identifier)
-        (type_identifier))))
+          (type_identifier)))))
   (type_alias_declaration
     (type_identifier)
     (type_parameters
@@ -1205,20 +1205,20 @@ type T<X> = T extends { x: infer X extends number } ? X : never;
       (type_identifier)
       (generic_type
         (type_identifier)
-        (type_arguments
-          (infer_type (type_identifier))))
+        (type_arguments (infer_type (type_identifier))))
       (type_identifier)
       (type_identifier)))
-    (type_alias_declaration
+  (type_alias_declaration
+    (type_identifier)
+    (type_parameters
+      (type_parameter (type_identifier)))
+    (conditional_type
       (type_identifier)
-      (type_parameters
-        (type_parameter (type_identifier)))
-      (conditional_type
-        (type_identifier)
-        (array_type
-          (parenthesized_type (infer_type (type_identifier))))
-        (type_identifier)
-        (predefined_type)))
+      (array_type
+        (parenthesized_type
+          (infer_type (type_identifier))))
+      (type_identifier)
+      (predefined_type)))
   (type_alias_declaration
     (type_identifier)
     (type_parameters
@@ -1568,7 +1568,7 @@ type Foo<T> = abstract new () => T;
 
 ---
 
-(program (type_alias_declaration (type_identifier) (type_parameters (type_parameter (type_identifier))) (constructor_type (formal_parameters) (type_identifier)))) 
+(program (type_alias_declaration (type_identifier) (type_parameters (type_parameter (type_identifier))) (constructor_type (formal_parameters) (type_identifier))))
 
 =========================
 Indexed Access Precedence

common/define-grammar.js

@@ -141,7 +141,7 @@ module.exports = function defineGrammar(dialect) {
         optional('declare'),
         optional($.accessibility_modifier),
         choice(
-          seq(optional('static'), optional($.override_modifier), optional('readonly')), 
+          seq(optional('static'), optional($.override_modifier), optional('readonly')),
           seq(optional('abstract'), optional('readonly')),
           seq(optional('readonly'), optional('abstract')),
         ),
@@ -386,7 +386,7 @@ module.exports = function defineGrammar(dialect) {
           // *definition*, not a declaration. Example:
           //     public foo()
           //     { <--- this brace made the method signature become a definition
-          //     }      
+          //     }
           // The same rule applies for functions and that's why we use
           // "_function_signature_automatic_semicolon".
           seq($.method_signature, choice($._function_signature_automatic_semicolon, ',')),
@@ -716,7 +716,7 @@ module.exports = function defineGrammar(dialect) {
         ))
       )),
 
-      conditional_type: $ => prec.left(seq(
+      conditional_type: $ => prec.right(seq(
         field('left', $._type),
         'extends',
         field('right', $._type),

tsx/src/grammar.json

@@ -8992,7 +8992,7 @@
       }
     },
     "conditional_type": {
-      "type": "PREC_LEFT",
+      "type": "PREC_RIGHT",
       "value": 0,
       "content": {
         "type": "SEQ",