From af6d8a7b62adda4118f51f28b265f4e47bfa42e9 Mon Sep 17 00:00:00 2001
From: Techassi <git@techassi.dev>
Date: Tue, 29 Sep 2026 09:30:02 +0200
Subject: [PATCH 1/2] feat(versioned): Add "map" hint

This now allows users to hint for Hash and BTreeMaps by converting
the values and passing the keys unchanged.
---
 crates/stackable-versioned-macros/src/attrs/item/field.rs   | 1 +
 crates/stackable-versioned-macros/src/codegen/item/field.rs | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/crates/stackable-versioned-macros/src/attrs/item/field.rs b/crates/stackable-versioned-macros/src/attrs/item/field.rs
index 47811b5b9..8c45c4471 100644
--- a/crates/stackable-versioned-macros/src/attrs/item/field.rs
+++ b/crates/stackable-versioned-macros/src/attrs/item/field.rs
@@ -92,4 +92,5 @@ impl FieldAttributes {
 pub enum Hint {
     Option,
     Vec,
+    Map,
 }
diff --git a/crates/stackable-versioned-macros/src/codegen/item/field.rs b/crates/stackable-versioned-macros/src/codegen/item/field.rs
index 96774a78d..ea074aeea 100644
--- a/crates/stackable-versioned-macros/src/codegen/item/field.rs
+++ b/crates/stackable-versioned-macros/src/codegen/item/field.rs
@@ -442,6 +442,9 @@ impl VersionedField {
                 Hint::Vec => {
                     quote! { into_iter().map(|v| v.tracking_into(status, &#json_path_ident)).collect() }
                 }
+                Hint::Map => {
+                    quote! { into_iter().map(|(k, v)| (k, v.tracking_into(status, &#json_path_ident))).collect() }
+                }
             }
         } else {
             quote! { tracking_into(status, &#json_path_ident) }
@@ -454,6 +457,7 @@ impl VersionedField {
             match hint {
                 Hint::Option => quote! { map(Into::into) },
                 Hint::Vec => quote! { into_iter().map(Into::into).collect() },
+                Hint::Map => quote! { into_iter().map(|(k, v)| (k, v.into())).collect() },
             }
         } else {
             quote! { into() }

From 4fb3ce724ef0ebcba21faa2c986c0b4eba90df56 Mon Sep 17 00:00:00 2001
From: Techassi <git@techassi.dev>
Date: Tue, 29 Sep 2026 09:52:24 +0200
Subject: [PATCH 2/2] test(versioned): Add snapshot test for "map" hint

---
 .../tests/inputs/pass/hint_map.rs             | 31 ++++++++++++++++
 ...d_macros__snapshots__pass@hint_map.rs.snap | 35 +++++++++++++++++++
 .../tests/trybuild.rs                         |  1 +
 3 files changed, 67 insertions(+)
 create mode 100644 crates/stackable-versioned-macros/tests/inputs/pass/hint_map.rs
 create mode 100644 crates/stackable-versioned-macros/tests/snapshots/stackable_versioned_macros__snapshots__pass@hint_map.rs.snap

diff --git a/crates/stackable-versioned-macros/tests/inputs/pass/hint_map.rs b/crates/stackable-versioned-macros/tests/inputs/pass/hint_map.rs
new file mode 100644
index 000000000..9e9784615
--- /dev/null
+++ b/crates/stackable-versioned-macros/tests/inputs/pass/hint_map.rs
@@ -0,0 +1,31 @@
+use std::collections::HashMap;
+
+use stackable_versioned::versioned;
+// ---
+#[versioned(version(name = "v1alpha1"), version(name = "v1alpha2"))]
+// ---
+pub(crate) mod versioned {
+    pub(crate) struct Foo {
+        #[versioned(
+            changed(since = "v1alpha2", from_type = "HashMap<String, u8>"),
+            hint(map)
+        )]
+        bar: HashMap<String, Bar>,
+    }
+}
+// ---
+struct Bar(u8);
+
+impl From<u8> for Bar {
+    fn from(value: u8) -> Self {
+        Self(value)
+    }
+}
+
+impl From<Bar> for u8 {
+    fn from(value: Bar) -> Self {
+        value.0
+    }
+}
+
+fn main() {}
diff --git a/crates/stackable-versioned-macros/tests/snapshots/stackable_versioned_macros__snapshots__pass@hint_map.rs.snap b/crates/stackable-versioned-macros/tests/snapshots/stackable_versioned_macros__snapshots__pass@hint_map.rs.snap
new file mode 100644
index 000000000..0a4eb3c23
--- /dev/null
+++ b/crates/stackable-versioned-macros/tests/snapshots/stackable_versioned_macros__snapshots__pass@hint_map.rs.snap
@@ -0,0 +1,35 @@
+---
+source: crates/stackable-versioned-macros/src/lib.rs
+expression: formatted
+input_file: crates/stackable-versioned-macros/tests/inputs/pass/hint_map.rs
+---
+#[automatically_derived]
+pub(crate) mod v1alpha1 {
+    use super::*;
+    pub struct Foo {
+        pub bar: HashMap<String, u8>,
+    }
+}
+#[automatically_derived]
+impl ::core::convert::From<v1alpha1::Foo> for v1alpha2::Foo {
+    fn from(__sv_foo: v1alpha1::Foo) -> Self {
+        Self {
+            bar: __sv_foo.bar.into_iter().map(|(k, v)| (k, v.into())).collect(),
+        }
+    }
+}
+#[automatically_derived]
+impl ::core::convert::From<v1alpha2::Foo> for v1alpha1::Foo {
+    fn from(__sv_foo: v1alpha2::Foo) -> Self {
+        Self {
+            bar: __sv_foo.bar.into_iter().map(|(k, v)| (k, v.into())).collect(),
+        }
+    }
+}
+#[automatically_derived]
+pub(crate) mod v1alpha2 {
+    use super::*;
+    pub struct Foo {
+        pub bar: HashMap<String, Bar>,
+    }
+}
diff --git a/crates/stackable-versioned-macros/tests/trybuild.rs b/crates/stackable-versioned-macros/tests/trybuild.rs
index 90ec9b20a..94eb6dd48 100644
--- a/crates/stackable-versioned-macros/tests/trybuild.rs
+++ b/crates/stackable-versioned-macros/tests/trybuild.rs
@@ -28,6 +28,7 @@ mod inputs {
         // mod docs;
         // mod downgrade_with;
         // mod enum_fields;
+        // mod hint_map;
         // mod module;
         // mod module_preserve;
         // mod renamed_field;