Support graphql aliases on links_of_type

app/graphql/types/links_type.rb

@@ -1,7 +1,7 @@
 module Types
   class LinksType < Types::BaseObject
     field :available_translations, [EditionType], null: true
-    field :links_of_type, [EditionType] do
+    field :links_of_type, [EditionType], extras: [:ast_node] do
       argument :type, String, required: true
       argument :reverse, Boolean, default_value: false
     end
@@ -30,7 +30,10 @@ def available_translations
     end
 
     # rubocop:disable Lint/UnusedMethodArgument
-    def links_of_type(type:, reverse:) = object.dig(:links, type)
+    def links_of_type(type:, reverse:, ast_node:)
+      key = ast_node.alias || type
+      object.dig(:links, key)
+    end
     # rubocop:enable Lint/UnusedMethodArgument
   end
 end

app/models/expanded_edition_dataset.rb

@@ -8,8 +8,8 @@ def get_or_prepare_statement(include_drafts: false, include_withdrawn: false, lo
     db = Sequel::Model.db
 
     paths_from_json_sql = <<~SQL
-      SELECT path, next, columns
-      FROM json_to_recordset(?) AS paths(path text[], next text, columns jsonb)
+      SELECT path, next, next_alias, columns
+      FROM json_to_recordset(?) AS paths(path text[], next text, next_alias text, columns jsonb)
     SQL
 
     state_filter = ["published", ("draft" if include_drafts), ("unpublished" if include_withdrawn)].compact
@@ -34,7 +34,7 @@ def get_or_prepare_statement(include_drafts: false, include_withdrawn: false, lo
       *PathTreeHelpers::ALL_EDITION_COLUMNS.without(:state).map { Sequel[:editions][it] },
     ].compact
     child_selections = [
-      Sequel[:edition_links][:path].pg_array.push(Sequel[:link_type].cast(:text)).as(:path),
+      Sequel[:edition_links][:path].pg_array.push(Sequel[:next_alias]).as(:path),
       Sequel[:edition_links][:id_path].pg_array.push(Sequel[:editions][:id]).as(:id_path),
       Sequel[:documents][:content_id].as(:content_id),
       Sequel[:documents][:id].as(:document_id),

lib/path_tree_helpers.rb

@@ -43,8 +43,9 @@ def self.build_paths(lookahead)
 
   def self.build_path(raw_path)
     {
-      path: raw_path[0...-1].map { it[:type] },
+      path: raw_path[0...-1].map { it[:alias] || it[:type] },
       next: raw_path.last[:type],
+      next_alias: raw_path.last[:alias] || raw_path.last[:type],
       columns: raw_path.last[:columns],
     }
   end
@@ -60,6 +61,8 @@ def self.extract_paths(lookahead, current_path = [])
   def self.build_segment(selection)
     segment = {}
     segment = segment.merge(selection.arguments)
+    selection.ast_nodes.map(&:alias) => [ selection_alias ]
+    segment = segment.merge({ alias: selection_alias }) if selection_alias.present?
     segment.merge({ columns: (selection.selections.map(&:name).to_set & ALL_EDITION_COLUMNS).index_with(true) })
   end
 

test/lib/path_tree_helpers_test.rb

@@ -5,30 +5,33 @@
 require_relative "../test_helper"
 
 class PathTreeHelpersTest < Minitest::Test
-  Selection = Data.define(:name, :arguments, :selections)
+  AstNode = Data.define(:alias)
+  Selection = Data.define(:name, :ast_nodes, :arguments, :selections)
+
   def test_extract_paths
+    ast_nodes = [AstNode.new(alias: nil)]
     lookahead = Minitest::Mock.new
     lookahead.expect :selections, [
-      Selection.new(name: :links, arguments: {}, selections: [
-        Selection.new(name: :links_of_type, arguments: { name: "person" }, selections: [
-          Selection.new(name: :base_path, arguments: {}, selections: []),
-          Selection.new(name: :title, arguments: {}, selections: []),
-          Selection.new(name: :links, arguments: {}, selections: [
-            Selection.new(name: :links_of_type, arguments: { name: "person", reverse: true }, selections: [
-              Selection.new(name: :base_path, arguments: {}, selections: []),
-              Selection.new(name: :title, arguments: {}, selections: []),
-              Selection.new(name: :links, arguments: {}, selections: [
-                Selection.new(name: :links_of_type, arguments: { name: "role" }, selections: [
-                  Selection.new(name: :base_path, arguments: {}, selections: []),
-                  Selection.new(name: :title, arguments: {}, selections: []),
+      Selection.new(name: :links, ast_nodes:, arguments: {}, selections: [
+        Selection.new(name: :links_of_type, ast_nodes:, arguments: { name: "person" }, selections: [
+          Selection.new(name: :base_path, ast_nodes: [], arguments: {}, selections: []),
+          Selection.new(name: :title, ast_nodes:, arguments: {}, selections: []),
+          Selection.new(name: :links, ast_nodes:, arguments: {}, selections: [
+            Selection.new(name: :links_of_type, ast_nodes:, arguments: { name: "person", reverse: true }, selections: [
+              Selection.new(name: :base_path, ast_nodes:, arguments: {}, selections: []),
+              Selection.new(name: :title, ast_nodes:, arguments: {}, selections: []),
+              Selection.new(name: :links, ast_nodes:, arguments: {}, selections: [
+                Selection.new(name: :links_of_type, ast_nodes:, arguments: { name: "role" }, selections: [
+                  Selection.new(name: :base_path, ast_nodes:, arguments: {}, selections: []),
+                  Selection.new(name: :title, ast_nodes:, arguments: {}, selections: []),
                 ]),
               ]),
             ]),
           ]),
         ]),
-        Selection.new(name: :links_of_type, arguments: { name: "organisation" }, selections: [
-          Selection.new(name: :base_path, arguments: {}, selections: []),
-          Selection.new(name: :title, arguments: {}, selections: []),
+        Selection.new(name: :links_of_type, ast_nodes:, arguments: { name: "organisation" }, selections: [
+          Selection.new(name: :base_path, ast_nodes:, arguments: {}, selections: []),
+          Selection.new(name: :title, ast_nodes:, arguments: {}, selections: []),
         ]),
       ]),
     ]