fix(federation): match JS condition order with multiple skip/include …

…on the same selection

Rust was iterating in a consistent order, JS iterates in declaration
order.

Surprisingly this was the only place we use the consistent order. This
removes the `iter_sorted()` method from DirectiveList that is now no
longer used. Internally, DirectiveList still uses the consistent sort
order for hashing and equality.

I think it's somewhat nicer to use the consistent order here, so you do
not get different plans based on an innocuous input difference, but so
be it. We can consider using a consistent order everywhere we handle
directives in the future.

apollo-federation/src/operation/directive_list.rs

@@ -288,13 +288,6 @@ impl DirectiveList {
             .iter()
     }
 
-    /// Iterate the directives in a consistent sort order.
-    pub(crate) fn iter_sorted(&self) -> DirectiveIterSorted<'_> {
-        self.inner
-            .as_ref()
-            .map_or_else(DirectiveIterSorted::empty, |inner| inner.iter_sorted())
-    }
-
     /// Remove one directive application by name.
     ///
     /// To remove a repeatable directive, you may need to call this multiple times.
@@ -336,7 +329,7 @@ impl DirectiveList {
 }
 
 /// Iterate over a [`DirectiveList`] in a consistent sort order.
-pub(crate) struct DirectiveIterSorted<'a> {
+struct DirectiveIterSorted<'a> {
     directives: &'a [Node<executable::Directive>],
     inner: std::slice::Iter<'a, usize>,
 }
@@ -354,15 +347,6 @@ impl ExactSizeIterator for DirectiveIterSorted<'_> {
     }
 }
 
-impl DirectiveIterSorted<'_> {
-    fn empty() -> Self {
-        Self {
-            directives: &[],
-            inner: [].iter(),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::collections::HashSet;

apollo-federation/src/query_plan/conditions.rs

@@ -70,7 +70,7 @@ impl Conditions {
 
     pub(crate) fn from_directives(directives: &DirectiveList) -> Result<Self, FederationError> {
         let mut variables = IndexMap::default();
-        for directive in directives.iter_sorted() {
+        for directive in directives.iter() {
             let negated = match directive.name.as_str() {
                 "include" => false,
                 "skip" => true,

apollo-federation/tests/query_plan/supergraphs/condition_order_router799.graphql

@@ -0,0 +1,58 @@
+# Composed from subgraphs with hash: 3ebe0e8c55ad21763879da6341617f14953e80d7
+schema
+  @link(url: "https://specs.apollo.dev/link/v1.0")
+  @link(url: "https://specs.apollo.dev/join/v0.4", for: EXECUTION)
+{
+  query: Query
+  mutation: Mutation
+}
+
+directive @join__directive(graphs: [join__Graph!], name: String!, args: join__DirectiveArguments) repeatable on SCHEMA | OBJECT | INTERFACE | FIELD_DEFINITION
+
+directive @join__enumValue(graph: join__Graph!) repeatable on ENUM_VALUE
+
+directive @join__field(graph: join__Graph, requires: join__FieldSet, provides: join__FieldSet, type: String, external: Boolean, override: String, usedOverridden: Boolean, overrideLabel: String) repeatable on FIELD_DEFINITION | INPUT_FIELD_DEFINITION
+
+directive @join__graph(name: String!, url: String!) on ENUM_VALUE
+
+directive @join__implements(graph: join__Graph!, interface: String!) repeatable on OBJECT | INTERFACE
+
+directive @join__type(graph: join__Graph!, key: join__FieldSet, extension: Boolean! = false, resolvable: Boolean! = true, isInterfaceObject: Boolean! = false) repeatable on OBJECT | INTERFACE | UNION | ENUM | INPUT_OBJECT | SCALAR
+
+directive @join__unionMember(graph: join__Graph!, member: String!) repeatable on UNION
+
+directive @link(url: String, as: String, for: link__Purpose, import: [link__Import]) repeatable on SCHEMA
+
+scalar join__DirectiveArguments
+
+scalar join__FieldSet
+
+enum join__Graph {
+  BOOKS @join__graph(name: "books", url: "none")
+}
+
+scalar link__Import
+
+enum link__Purpose {
+  """
+  `SECURITY` features provide metadata necessary to securely resolve fields.
+  """
+  SECURITY
+
+  """
+  `EXECUTION` features provide metadata necessary for operation execution.
+  """
+  EXECUTION
+}
+
+type Mutation
+  @join__type(graph: BOOKS)
+{
+  bookName(name: String!): Int!
+}
+
+type Query
+  @join__type(graph: BOOKS)
+{
+  bookName: String!
+}