fix(es/codegen): Emit named type in mapped types (#9038)

**Description:**

Fixes the emit of mapped types.

crates/swc_ecma_codegen/src/typescript.rs

@@ -482,12 +482,14 @@ where
         }
 
         punct!("[");
+
         emit!(n.type_param.name);
 
-        if n.type_param.constraint.is_some() {
+        if let Some(constraints) = &n.type_param.constraint {
             space!();
             keyword!("in");
             space!();
+            emit!(constraints);
         }
 
         if let Some(default) = &n.type_param.default {
@@ -497,7 +499,12 @@ where
             emit!(default);
         }
 
-        emit!(n.type_param.constraint);
+        if let Some(name_type) = &n.name_type {
+            space!();
+            keyword!("as");
+            space!();
+            emit!(name_type);
+        }
 
         punct!("]");
 
@@ -518,9 +525,12 @@ where
             },
         }
 
-        punct!(":");
-        space!();
-        emit!(n.type_ann);
+        if let Some(type_ann) = &n.type_ann {
+            punct!(":");
+            space!();
+            emit!(type_ann);
+        }
+
         formatting_semi!();
 
         self.wr.write_line()?;

crates/swc_ecma_codegen/tests/fixture/typescript/mapped_type/input.ts

@@ -0,0 +1,27 @@
+type NoTypeAnn = {
+    [value: string];
+};
+type MappedTypeWithNamedType = {
+    [K in T as U]: undefined;
+};
+type Partial<T> = {
+    [P in keyof T]?: T[P];
+};
+type OptionalPlus<T> = {
+    [P in keyof T]+?: T[P];
+};
+type OptionalMinus<T> = {
+    [P in keyof T]-?: T[P];
+};
+type Flags<T> = {
+    [P in keyof T]: boolean;
+};
+type ReadOnly<T> = {
+    readonly [P in keyof T]: T[P];
+};
+type ReadOnlyPlus<T> = {
+    +readonly [P in keyof T]: T[P];
+};
+type ReadOnlyMinus<T> = {
+    -readonly [P in keyof T]: T[P];
+};

crates/swc_ecma_codegen/tests/fixture/typescript/mapped_type/output.ts

@@ -0,0 +1,27 @@
+type NoTypeAnn = {
+    [value: string];
+};
+type MappedTypeWithNamedType = {
+    [K in T as U]: undefined;
+};
+type Partial<T> = {
+    [P in keyof T]?: T[P];
+};
+type OptionalPlus<T> = {
+    [P in keyof T]+?: T[P];
+};
+type OptionalMinus<T> = {
+    [P in keyof T]-?: T[P];
+};
+type Flags<T> = {
+    [P in keyof T]: boolean;
+};
+type ReadOnly<T> = {
+    readonly [P in keyof T]: T[P];
+};
+type ReadOnlyPlus<T> = {
+    +readonly [P in keyof T]: T[P];
+};
+type ReadOnlyMinus<T> = {
+    -readonly [P in keyof T]: T[P];
+};

crates/swc_ecma_transforms_base/tests/ts-resolver/ts_mapped_type_as_clauses_01/output.ts

@@ -1,3 +1,3 @@
 type Lazyify__2<T__3> = {
-    [K__3 in keyof T__3]: () => T__3[K__3];
+    [K__3 in keyof T__3 as `get${Capitalize<K__3 & string>}`]: () => T__3[K__3];
 };