feat(stackable-versioned): Add conditional allow attr generation

Author: Techassi

crates/stackable-versioned-macros/src/codegen/chain.rs

@@ -5,6 +5,9 @@ where
     K: Ord + Eq,
 {
     fn get_neighbors(&self, key: &K) -> (Option<&V>, Option<&V>);
+    fn value_is<F>(&self, key: &K, f: F) -> bool
+    where
+        F: Fn(&V) -> bool;
 
     fn lo_bound(&self, bound: Bound<&K>) -> Option<(&K, &V)>;
     fn up_bound(&self, bound: Bound<&K>) -> Option<(&K, &V)>;
@@ -51,6 +54,13 @@ where
         }
     }
 
+    fn value_is<F>(&self, key: &K, f: F) -> bool
+    where
+        F: Fn(&V) -> bool,
+    {
+        self.get(key).map_or(false, f)
+    }
+
     fn lo_bound(&self, bound: Bound<&K>) -> Option<(&K, &V)> {
         self.range((Bound::Unbounded, bound)).next_back()
     }

crates/stackable-versioned-macros/src/codegen/vstruct/mod.rs

@@ -8,8 +8,10 @@ use syn::{parse_quote, DataStruct, Error, Ident};
 use crate::{
     attrs::common::ContainerAttributes,
     codegen::{
+        chain::Neighbors,
         common::{
-            Container, ContainerInput, ContainerVersion, Item, VersionExt, VersionedContainer,
+            Container, ContainerInput, ContainerVersion, Item, ItemStatus, VersionExt,
+            VersionedContainer,
         },
         vstruct::field::VersionedField,
     },
@@ -241,11 +243,20 @@ impl VersionedStruct {
 
             let fields = self.generate_from_fields(version, next_version, from_ident);
 
+            // Include allow(deprecated) only when this or the next version is
+            // deprecated. Also include it, when a field in this or the next
+            // version is deprecated.
+            let allow_attribute = (version.deprecated
+                || next_version.deprecated
+                || self.any_field_deprecated(version)
+                || self.any_field_deprecated(next_version))
+            .then_some(quote! { #[allow(deprecated)] });
+
             // TODO (@Techassi): Be a little bit more clever about when to include
             // the #[allow(deprecated)] attribute.
             return Some(quote! {
                 #[automatically_derived]
-                #[allow(deprecated)]
+                #allow_attribute
                 impl From<#module_name::#struct_ident> for #next_module_name::#struct_ident {
                     fn from(#from_ident: #module_name::#struct_ident) -> Self {
                         Self {
@@ -275,6 +286,25 @@ impl VersionedStruct {
 
         token_stream
     }
+
+    /// Returns whether any field is deprecated in the provided
+    /// [`ContainerVersion`].
+    fn any_field_deprecated(&self, version: &ContainerVersion) -> bool {
+        // First, iterate over all fields. Any will return true if any of the
+        // function invocations return true. If a field doesn't have a chain,
+        // we can safely default to false (unversioned fields cannot be
+        // deprecated). Then we retrieve the status of the field and ensure it
+        // is deprecated.
+        // TODO (@Techassi): This currently does not include fields which were
+        // already deprecated and thus now have the NoChange status.
+        self.items.iter().any(|f| {
+            f.chain.as_ref().map_or(false, |c| {
+                c.value_is(&version.inner, |a| {
+                    matches!(a, ItemStatus::Deprecation { .. })
+                })
+            })
+        })
+    }
 }
 
 // Kubernetes specific code generation

crates/stackable-versioned-macros/src/lib.rs

@@ -456,7 +456,7 @@ pub struct FooSpec {
 }
 
 # fn main() {
-let merged_crd = Foo::merged_crd("v1").unwrap();
+let merged_crd = Foo::merged_crd(Foo::V1).unwrap();
 println!("{}", serde_yaml::to_string(&merged_crd).unwrap());
 # }
 ```

crates/stackable-versioned-macros/tests/default/pass/deprecate.rs

@@ -7,7 +7,7 @@ fn main() {
         version(name = "v1")
     )]
     struct Foo {
-        #[versioned(deprecated(since = "v1beta1", note = "gone"))]
+        #[versioned(deprecated(since = "v1", note = "gone"))]
         deprecated_bar: usize,
         baz: bool,
     }