[WIP] Auto alias joins

db/migrations/20240317161918_create_interviews.cr

@@ -0,0 +1,14 @@
+class CreateInterviews::V20240317161918 < Avram::Migrator::Migration::V1
+  def migrate
+    create table_for(Interview) do
+      primary_key id : Int64
+      add_timestamps
+      add_belongs_to interviewer : User, on_delete: :cascade
+      add_belongs_to interviewee : User, on_delete: :cascade
+    end
+  end
+
+  def rollback
+    drop table_for(Interview)
+  end
+end

spec/avram/query_associations_spec.cr

@@ -176,4 +176,19 @@ describe "Query associations" do
 
     result.should eq(product)
   end
+
+  it "handles aliases" do
+    interviewer = UserFactory.create(&.available_for_hire(false).name("Interviewer"))
+    interviewee = UserFactory.create(&.available_for_hire(true).name("Interviewee"))
+    employed = UserFactory.create(&.available_for_hire(false).name("Employed"))
+    InterviewFactory.create(&.interviewee(interviewee).interviewer(interviewer))
+    InterviewFactory.create(&.interviewee(employed).interviewer(interviewer))
+
+    InterviewQuery.new
+      .join(Avram::Join::Inner.new(:interviews, :users, alias_to: :interviewers, primary_key: :interviewer_id, foreign_key: :id))
+      .join(Avram::Join::Inner.new(:interviews, :users, alias_to: :interviewees, primary_key: :interviewee_id, foreign_key: :id))
+      .where_interviewer(UserQuery.new("interviewers").available_for_hire(false), auto_inner_join: false)
+      .where_interviewee(UserQuery.new("interviewees").available_for_hire(true), auto_inner_join: false)
+      .select_count.should eq(1)
+  end
 end

spec/support/factories/interview_factory.cr

@@ -0,0 +1,20 @@
+class InterviewFactory < BaseFactory
+  def initialize
+    before_save do
+      if operation.interviewer_id.value.nil?
+        interviewer(UserFactory.create)
+      end
+      if operation.interviewee_id.value.nil?
+        interviewee(UserFactory.create)
+      end
+    end
+  end
+
+  def interviewer(u : User)
+    interviewer_id(u.id)
+  end
+
+  def interviewee(u : User)
+    interviewee_id(u.id)
+  end
+end

spec/support/models/interview.cr

@@ -0,0 +1,9 @@
+class Interview < BaseModel
+  table do
+    belongs_to interviewer : User
+    belongs_to interviewee : User
+  end
+end
+
+class InterviewQuery < Interview::BaseQuery
+end

src/avram/base_query_template.cr

@@ -4,6 +4,11 @@ class Avram::BaseQueryTemplate
       def_clone
       include Avram::Queryable({{ type }})
 
+      getter table_name : String = {{ type }}.table_name
+
+      def initialize(@table_name : String = {{ type }}.table_name)
+      end
+
       {% if type.resolve.has_constant?("PRIMARY_KEY_NAME") %}
         include Avram::PrimaryKeyQueryable({{ type }})
       {% end %}

src/avram/queryable.cr

@@ -7,7 +7,7 @@ module Avram::Queryable(T)
       .select(schema_class.column_names)
   end
 
-  delegate :database, :table_name, :primary_key_name, to: T
+  delegate :database, :primary_key_name, to: T
 
   macro included
     def self.new_with_existing_query(query : Avram::QueryBuilder)