From 1f3c76bca62fa62a05aaae8194c454d693ecc712 Mon Sep 17 00:00:00 2001
From: Liam Murphy <liampm32@gmail.com>
Date: Thu, 2 Feb 2023 03:48:22 +1100
Subject: [PATCH] fix: Make maplike `set` and setlike `add` return `this`, not
 `undefined` (#3270)

---
 crates/webidl-tests/globals.js  |  6 ++++--
 crates/webidl-tests/maplike.rs  |  6 ++++--
 crates/webidl-tests/setlike.rs  |  3 ++-
 crates/webidl/src/first_pass.rs | 20 ++++++++++++++------
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/crates/webidl-tests/globals.js b/crates/webidl-tests/globals.js
index bf70171c1ca..5816c108e42 100644
--- a/crates/webidl-tests/globals.js
+++ b/crates/webidl-tests/globals.js
@@ -207,7 +207,8 @@ global.TestReadWriteMapLike = class extends global.TestReadOnlyMapLike {
   }
 
   set(key, value) {
-    return this.map.set(key, value);
+    this.map.set(key, value);
+    return this;
   }
 
   delete(key) {
@@ -258,7 +259,8 @@ global.TestReadWriteSetLike = class extends global.TestReadOnlySetLike {
   }
 
   add(value) {
-    return this.set.add(value);
+    this.set.add(value);
+    return this;
   }
 
   delete(value) {
diff --git a/crates/webidl-tests/maplike.rs b/crates/webidl-tests/maplike.rs
index 758ed00a9b2..6e63eb1b76b 100644
--- a/crates/webidl-tests/maplike.rs
+++ b/crates/webidl-tests/maplike.rs
@@ -87,10 +87,12 @@ fn write_maplike() {
     let maplike = TestReadWriteMapLike::new().unwrap();
 
     // undefined set(K key, V value);
-    maplike.set("a", 4);
-    maplike.set("d", 5);
+    let ret1 = maplike.set("a", 4);
+    let ret2 = maplike.set("d", 5);
     assert_eq!(maplike.get("a"), Some(4));
     assert_eq!(maplike.get("d"), Some(5));
+    assert_eq!(ret1, maplike);
+    assert_eq!(ret2, maplike);
 
     // boolean delete(K key);
     assert!(maplike.delete("a"));
diff --git a/crates/webidl-tests/setlike.rs b/crates/webidl-tests/setlike.rs
index d77dd61c16e..74700627391 100644
--- a/crates/webidl-tests/setlike.rs
+++ b/crates/webidl-tests/setlike.rs
@@ -78,8 +78,9 @@ fn write_setlike() {
     // { "a", "b", "c" }
     let setlike = TestReadWriteSetLike::new().unwrap();
 
-    setlike.add("d");
+    let ret = setlike.add("d");
     assert_eq!(setlike.size(), 4);
+    assert_eq!(ret, setlike);
 
     assert!(setlike.delete("d"));
     assert_eq!(setlike.size(), 3);
diff --git a/crates/webidl/src/first_pass.rs b/crates/webidl/src/first_pass.rs
index 68e4a8c129d..91f3ed143bf 100644
--- a/crates/webidl/src/first_pass.rs
+++ b/crates/webidl/src/first_pass.rs
@@ -848,15 +848,19 @@ impl<'src> FirstPass<'src, (&'src str, ApiStability)>
                 stability,
             );
 
-            // TODO: `set` actually returns `this` but we don't have a way to express that just yet
-            // undefined set(K key, V value);
+            // <interface name> set(K key, V value);
             first_pass_operation(
                 record,
                 FirstPassOperationType::Interface,
                 self_name,
                 &[OperationId::Operation(Some("set"))],
                 [key_arg(), value_arg()],
-                &undefined_ret(),
+                &ReturnType::Type(Type::Single(SingleType::NonAny(NonAnyType::Identifier(
+                    MayBeNull {
+                        type_: Identifier(self_name),
+                        q_mark: None,
+                    },
+                )))),
                 &None,
                 false,
                 stability,
@@ -1051,15 +1055,19 @@ impl<'src> FirstPass<'src, (&'src str, ApiStability)>
                 ctx.1,
             );
 
-            // TODO: `add` actually returns `this` but we don't have a way to express that just yet
-            // undefined add(V value);
+            // <interface name> add(V value);
             first_pass_operation(
                 record,
                 FirstPassOperationType::Interface,
                 ctx.0,
                 &[OperationId::Operation(Some("add"))],
                 [value_arg()],
-                &undefined_ret(),
+                &ReturnType::Type(Type::Single(SingleType::NonAny(NonAnyType::Identifier(
+                    MayBeNull {
+                        type_: Identifier(ctx.0),
+                        q_mark: None,
+                    },
+                )))),
                 &None,
                 false,
                 ctx.1,