Fixes #1907

2 files changed, 112 insertions, 1 deletions

diff --git a/src/js_parser.zig b/src/js_parser.zig
index ab9c9bec6..4159faada 100644
--- a/src/js_parser.zig
+++ b/src/js_parser.zig
@@ -2184,6 +2184,7 @@ const PropertyOpts = struct {
     is_class: bool = false,
     class_has_extends: bool = false,
     allow_ts_decorators: bool = false,
+    is_ts_abstract: bool = false,
     ts_decorators: []Expr = &[_]Expr{},
     has_argument_decorators: bool = false,
 };
@@ -10218,7 +10219,26 @@ fn NewParser_(
                                             return try p.parseProperty(kind, opts, null);
                                         }
                                     },
-                                    .p_private, .p_protected, .p_public, .p_readonly, .p_abstract, .p_declare, .p_override => {
+                                    .p_declare => {
+                                        // skip declare keyword entirely
+                                        // https://github.com/oven-sh/bun/issues/1907
+                                        if (opts.is_class and is_typescript_enabled and strings.eqlComptime(raw, "declare")) {
+                                            const scope_index = p.scopes_in_order.items.len;
+                                            _ = try p.parseProperty(kind, opts, null);
+                                            p.discardScopesUpTo(scope_index);
+                                            return null;
+                                        }
+                                    },
+                                    .p_abstract => {
+                                        if (opts.is_class and is_typescript_enabled and !opts.is_ts_abstract and strings.eqlComptime(raw, "abstract")) {
+                                            opts.is_ts_abstract = true;
+                                            const scope_index = p.scopes_in_order.items.len;
+                                            _ = try p.parseProperty(kind, opts, null);
+                                            p.discardScopesUpTo(scope_index);
+                                            return null;
+                                        }
+                                    },
+                                    .p_private, .p_protected, .p_public, .p_readonly, .p_override => {
                                         // Skip over TypeScript keywords
                                         if (opts.is_class and is_typescript_enabled and (js_lexer.PropertyModifierKeyword.List.get(raw) orelse .p_static) == keyword) {
                                             return try p.parseProperty(kind, opts, null);
diff --git a/test/bun.js/transpiler.test.js b/test/bun.js/transpiler.test.js
index 0e51970cb..62df8d76b 100644
--- a/test/bun.js/transpiler.test.js
+++ b/test/bun.js/transpiler.test.js
@@ -80,6 +80,97 @@ describe("Bun.Transpiler", () => {
       );
     });
 
+    it("modifiers", () => {
+      const exp = ts.expectPrinted_;
+
+      exp("class Foo { public foo: number }", "class Foo {\n  foo;\n}");
+      exp("class Foo { private foo: number }", "class Foo {\n  foo;\n}");
+      exp("class Foo { protected foo: number }", "class Foo {\n  foo;\n}");
+      exp("class Foo { declare foo: number }", "class Foo {\n}");
+      exp("class Foo { declare public foo: number }", "class Foo {\n}");
+      exp("class Foo { public declare foo: number }", "class Foo {\n}");
+      exp("class Foo { override foo: number }", "class Foo {\n  foo;\n}");
+      exp(
+        "class Foo { override public foo: number }",
+        "class Foo {\n  foo;\n}",
+      );
+      exp(
+        "class Foo { public override foo: number }",
+        "class Foo {\n  foo;\n}",
+      );
+      exp(
+        "class Foo { declare override public foo: number }",
+        "class Foo {\n}",
+      );
+      exp("class Foo { declare foo = 123 }", "class Foo {\n}");
+
+      exp(
+        "class Foo { public static foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp(
+        "class Foo { private static foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp(
+        "class Foo { protected static foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp("class Foo { declare static foo: number }", "class Foo {\n}");
+      exp("class Foo { declare public static foo: number }", "class Foo {\n}");
+      exp("class Foo { public declare static foo: number }", "class Foo {\n}");
+      exp("class Foo { public static declare foo: number }", "class Foo {\n}");
+      exp(
+        "class Foo { override static foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp(
+        "class Foo { override public static foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp(
+        "class Foo { public override static foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp(
+        "class Foo { public static override foo: number }",
+        "class Foo {\n  static foo;\n}",
+      );
+      exp(
+        "class Foo { declare override public static foo: number }",
+        "class Foo {\n}",
+      );
+      exp("class Foo { declare static foo = 123 }", "class Foo {\n}");
+      exp("class Foo { static declare foo = 123 }", "class Foo {\n}");
+
+      exp("let x: abstract new () => void = Foo", "let x = Foo");
+      exp("let x: abstract new <T>() => Foo<T>", "let x");
+    });
+
+    it("types", () => {
+      exp("x as 1 < 1", "x < 1");
+      exp("x as 1n < 1", "x < 1");
+      exp("x as -1 < 1", "x < 1");
+      exp("x as -1n < 1", "x < 1");
+      exp("x as '' < 1", "x < 1");
+      exp("x as `` < 1", "x < 1");
+      exp("x as any < 1", "x < 1");
+      exp("x as bigint < 1", "x < 1");
+      exp("x as false < 1", "x < 1");
+      exp("x as never < 1", "x < 1");
+      exp("x as null < 1", "x < 1");
+      exp("x as number < 1", "x < 1");
+      exp("x as object < 1", "x < 1");
+      exp("x as string < 1", "x < 1");
+      exp("x as symbol < 1", "x < 1");
+      exp("x as this < 1", "x < 1");
+      exp("x as true < 1", "x < 1");
+      exp("x as undefined < 1", "x < 1");
+      exp("x as unique symbol < 1", "x < 1");
+      exp("x as unknown < 1", "x < 1");
+      exp("x as void < 1", "x < 1");
+    });
+
     it("class constructor", () => {
       const fixtures = [
         [