From fa2943a1d885963e618e32c33fa5c40b9a6e80fa Mon Sep 17 00:00:00 2001
From: Egor Blinov <egor.b@miro.com>
Date: Sat, 29 Jun 2024 12:56:15 +0200
Subject: [PATCH] fix(isolated_declarations): inferring literal types for
 readonly class fileds

---
 crates/oxc_isolated_declarations/src/class.rs       |  9 ++++++++-
 .../tests/fixtures/class.ts                         | 13 +++++++++++--
 .../tests/snapshots/class.snap                      |  4 ++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/crates/oxc_isolated_declarations/src/class.rs b/crates/oxc_isolated_declarations/src/class.rs
index 6e668808d15b3..0316624b8194e 100644
--- a/crates/oxc_isolated_declarations/src/class.rs
+++ b/crates/oxc_isolated_declarations/src/class.rs
@@ -66,7 +66,11 @@ impl<'a> IsolatedDeclarations<'a> {
                         .value
                         .as_ref()
                         .and_then(|expr| {
-                            let ts_type = self.infer_type_from_expression(expr);
+                            let ts_type = if property.readonly {
+                                self.transform_expression_to_ts_type(expr)
+                            } else {
+                                self.infer_type_from_expression(expr)
+                            };
                             if ts_type.is_none() {
                                 self.error(property_must_have_explicit_type(property.key.span()));
                             }
@@ -76,6 +80,9 @@ impl<'a> IsolatedDeclarations<'a> {
                 })
         };
 
+        // TODO if inferred type_annotations is TSLiteral, it should stand as value,
+        // so `field = 'string'` remain `field = 'string'` instead of `field: 'string'`
+
         self.ast.class_property(
             property.r#type,
             property.span,
diff --git a/crates/oxc_isolated_declarations/tests/fixtures/class.ts b/crates/oxc_isolated_declarations/tests/fixtures/class.ts
index f0f9579b28cc5..e5a4f40ddea25 100644
--- a/crates/oxc_isolated_declarations/tests/fixtures/class.ts
+++ b/crates/oxc_isolated_declarations/tests/fixtures/class.ts
@@ -6,10 +6,19 @@ export class Bar {
   public constructor(a: number = 0) {}
 }
 
-export class Zoo { foo<F>(f: F): F { return f } }
+export class Zoo {
+  foo<F>(f: F): F {
+    return f;
+  }
+}
 
 export abstract class Qux {
   abstract foo(): void;
   bar(): void {}
   baz(): void {}
-}
\ No newline at end of file
+}
+
+export class Baz {
+  readonly prop1 = 'some string';
+  prop2 = 'another string';
+}
diff --git a/crates/oxc_isolated_declarations/tests/snapshots/class.snap b/crates/oxc_isolated_declarations/tests/snapshots/class.snap
index e0815c35192ab..2a754eedce393 100644
--- a/crates/oxc_isolated_declarations/tests/snapshots/class.snap
+++ b/crates/oxc_isolated_declarations/tests/snapshots/class.snap
@@ -18,3 +18,7 @@ export declare abstract class Qux {
 	bar(): void;
 	baz(): void;
 }
+export declare class Baz {
+	readonly prop1: 'some string';
+	prop2: string;
+}