fix(es/parser): Parse const type parameters in arrow function expre…

…ssions (#7242)

crates/swc_ecma_parser/src/parser/expr.rs

@@ -105,7 +105,7 @@ impl<I: Tokens> Parser<I> {
                     }
                 }
 
-                let type_parameters = p.parse_ts_type_params(false, false)?;
+                let type_parameters = p.parse_ts_type_params(false, true)?;
                 let mut arrow = p.parse_assignment_expr_base()?;
                 match *arrow {
                     Expr::Arrow(ArrowExpr {

crates/swc_ecma_parser/src/parser/typescript.rs

@@ -398,16 +398,16 @@ impl<I: Tokens> Parser<I> {
         )? {
             match modifer {
                 "const" => {
+                    is_const = true;
                     if !permit_const {
                         self.emit_err(
                             self.input.prev_span(),
                             SyntaxError::TS1277(js_word!("const")),
                         );
-                    } else {
-                        is_const = true;
                     }
                 }
                 "in" => {
+                    is_in = true;
                     if !permit_in_out {
                         self.emit_err(self.input.prev_span(), SyntaxError::TS1274(js_word!("in")));
                     } else if is_in {
@@ -417,17 +417,14 @@ impl<I: Tokens> Parser<I> {
                             self.input.prev_span(),
                             SyntaxError::TS1029(js_word!("in"), js_word!("out")),
                         );
-                    } else {
-                        is_in = true;
                     }
                 }
                 "out" => {
+                    is_out = true;
                     if !permit_in_out {
                         self.emit_err(self.input.prev_span(), SyntaxError::TS1274(js_word!("out")));
                     } else if is_out {
                         self.emit_err(self.input.prev_span(), SyntaxError::TS1030(js_word!("out")));
-                    } else {
-                        is_out = true;
                     }
                 }
                 other => self.emit_err(self.input.prev_span(), SyntaxError::TS1273(other.into())),

crates/swc_ecma_parser/tests/typescript-errors/variance-annotations/1/input.ts.swc-stderr

@@ -1,4 +1,152 @@
 
+  x 'out' modifier already seen.
+   ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:1:1]
+ 1 | type Covariant<out T> = {
+   :                ^^^
+ 2 |     x: T;
+   `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:10:1]
+ 10 | 
+ 11 | type Contravariant<in T> = {
+    :                    ^^
+ 12 |     f: (x: T) => void;
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:20:1]
+ 20 | 
+ 21 | type Invariant<in out T> = {
+    :                ^^
+ 22 |     f: (x: T) => T;
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:20:1]
+ 20 | 
+ 21 | type Invariant<in out T> = {
+    :                   ^^^
+ 22 |     f: (x: T) => T;
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:32:1]
+ 32 | 
+ 33 | type T10<out T> = T;
+    :          ^^^
+ 34 | type T11<in T> = keyof T;
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:33:1]
+ 33 | type T10<out T> = T;
+ 34 | type T11<in T> = keyof T;
+    :          ^^
+ 35 | type T12<out T, out K extends keyof T> = T[K];
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:34:1]
+ 34 | type T11<in T> = keyof T;
+ 35 | type T12<out T, out K extends keyof T> = T[K];
+    :          ^^^
+ 36 | type T13<in out T> = T[keyof T];
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:34:1]
+ 34 | type T11<in T> = keyof T;
+ 35 | type T12<out T, out K extends keyof T> = T[K];
+    :                 ^^^
+ 36 | type T13<in out T> = T[keyof T];
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:35:1]
+ 35 | type T12<out T, out K extends keyof T> = T[K];
+ 36 | type T13<in out T> = T[keyof T];
+    :          ^^
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:35:1]
+ 35 | type T12<out T, out K extends keyof T> = T[K];
+ 36 | type T13<in out T> = T[keyof T];
+    :             ^^^
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:39:1]
+ 39 | 
+ 40 | type Covariant1<in T> = {  // Error
+    :                 ^^
+ 41 |     x: T;
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:43:1]
+ 43 | 
+ 44 | type Contravariant1<out T> = keyof T;  // Error
+    :                     ^^^
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:45:1]
+ 45 | 
+ 46 | type Contravariant2<out T> = {  // Error
+    :                     ^^^
+ 47 |     f: (x: T) => void;
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:49:1]
+ 49 | 
+ 50 | type Invariant1<in T> = {  // Error
+    :                 ^^
+ 51 |     f: (x: T) => T;
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:53:1]
+ 53 | 
+ 54 | type Invariant2<out T> = {  // Error
+    :                 ^^^
+ 55 |     f: (x: T) => T;
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:59:1]
+ 59 | 
+ 60 | type Foo1<in T> = {  // Error
+    :           ^^
+ 61 |     x: T;
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:70:1]
+ 70 | 
+ 71 | type Foo2<out T> = {  // Error
+    :           ^^^
+ 72 |     x: T;
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:81:1]
+ 81 | 
+ 82 | type Foo3<in out T> = {
+    :           ^^
+ 83 |     x: T;
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:81:1]
+ 81 | 
+ 82 | type Foo3<in out T> = {
+    :              ^^^
+ 83 |     x: T;
+    `----
+
   x 'public' modifier cannot appear on a type parameter
     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:94:1]
  94 | 
@@ -10,11 +158,43 @@
   x 'in' modifier already seen.
     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:95:1]
  95 | type T20<public T> = T;  // Error
+ 96 | type T21<in out in T> = T;  // Error
+    :          ^^
+ 97 | type T22<in out out T> = T;  // Error
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:95:1]
+ 95 | type T20<public T> = T;  // Error
+ 96 | type T21<in out in T> = T;  // Error
+    :             ^^^
+ 97 | type T22<in out out T> = T;  // Error
+    `----
+
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:95:1]
+ 95 | type T20<public T> = T;  // Error
  96 | type T21<in out in T> = T;  // Error
     :                 ^^
  97 | type T22<in out out T> = T;  // Error
     `----
 
+  x 'in' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:96:1]
+ 96 | type T21<in out in T> = T;  // Error
+ 97 | type T22<in out out T> = T;  // Error
+    :          ^^
+ 98 | type T23<out in T> = T;  // Error
+    `----
+
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:96:1]
+ 96 | type T21<in out in T> = T;  // Error
+ 97 | type T22<in out out T> = T;  // Error
+    :             ^^^
+ 98 | type T23<out in T> = T;  // Error
+    `----
+
   x 'out' modifier already seen.
     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:96:1]
  96 | type T21<in out in T> = T;  // Error
@@ -23,7 +203,14 @@
  98 | type T23<out in T> = T;  // Error
     `----
 
-  x 'in' modifier must precede 'out' modifier.
+  x 'out' modifier already seen.
+    ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:97:1]
+ 97 | type T22<in out out T> = T;  // Error
+ 98 | type T23<out in T> = T;  // Error
+    :          ^^^
+    `----
+
+  x 'in' modifier already seen.
     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:97:1]
  97 | type T22<in out out T> = T;  // Error
  98 | type T23<out in T> = T;  // Error
@@ -60,3 +247,42 @@
      :     ^^^
  106 | }
      `----
+
+  x 'out' modifier already seen.
+     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:109:1]
+ 109 | 
+ 110 | interface Baz<out T> {}
+     :               ^^^
+ 111 | interface Baz<in T> {}
+     `----
+
+  x 'in' modifier already seen.
+     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:110:1]
+ 110 | interface Baz<out T> {}
+ 111 | interface Baz<in T> {}
+     :               ^^
+     `----
+
+  x 'out' modifier already seen.
+     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:120:1]
+ 120 | 
+ 121 | interface Parent<out A> {
+     :                  ^^^
+ 122 |     child: Child<A> | null;
+     `----
+
+  x 'in' modifier already seen.
+     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:139:1]
+ 139 | 
+ 140 | declare class StateNode<TContext, in out TEvent extends { type: string }> {
+     :                                   ^^
+ 141 |     _storedEvent: TEvent;
+     `----
+
+  x 'out' modifier already seen.
+     ,-[$DIR/tests/typescript-errors/variance-annotations/1/input.ts:139:1]
+ 139 | 
+ 140 | declare class StateNode<TContext, in out TEvent extends { type: string }> {
+     :                                      ^^^
+ 141 |     _storedEvent: TEvent;
+     `----

crates/swc_ecma_parser/tests/typescript/arrow-function/const-type-param/input.ts

@@ -0,0 +1 @@
+export const fn = <const Data extends Type>(payload: Data) => payload;