Make querying associations more explicit

Closes #171

spec/query_associations_spec.cr

@@ -1,5 +1,12 @@
 require "./spec_helper"
 
+# Ensure it works with inherited query classes
+class CommentQuery < Comment::BaseQuery
+  def body_eq(value)
+    body.eq(value)
+  end
+end
+
 describe "Query associations" do
   it "can query associations" do
     post_with_matching_comment = PostBox.create
@@ -16,10 +23,12 @@ describe "Query associations" do
       .post_id(post_without_matching_comment.id)
       .create
 
-    posts = Post::BaseQuery.new.join_comments.where_comments(&.body.eq("matching"))
+    posts = Post::BaseQuery.new
+      .where_comments(CommentQuery.new.body_eq("matching"))
     posts.results.should eq([post_with_matching_comment])
 
-    posts = Post::BaseQuery.new.join_comments.where_comments(&.body("matching"))
+    posts = Post::BaseQuery.new
+      .where_comments(Comment::BaseQuery.new.body("matching"))
     posts.results.should eq([post_with_matching_comment])
   end
 
@@ -38,7 +47,9 @@ describe "Query associations" do
       .post_id(post_without_matching_comment.id)
       .create
 
-    posts = Post::BaseQuery.new.inner_join_comments.where_comments(&.body.eq("matching"))
+    posts = Post::BaseQuery.new
+      .inner_join_comments
+      .where_comments(Comment::BaseQuery.new.body.eq("matching"), auto_inner_join: false)
     posts.to_sql[0].should contain "INNER JOIN"
     posts.results.should eq([post_with_matching_comment])
   end
@@ -58,7 +69,9 @@ describe "Query associations" do
       .post_id(post_without_matching_comment.id)
       .create
 
-    posts = Post::BaseQuery.new.left_join_comments.where_comments(&.body.eq("matching"))
+    posts = Post::BaseQuery.new
+      .left_join_comments
+      .where_comments(Comment::BaseQuery.new.body.eq("matching"), auto_inner_join: false)
     posts.to_sql[0].should contain "LEFT JOIN"
     posts.results.should eq([post_with_matching_comment])
   end
@@ -78,7 +91,9 @@ describe "Query associations" do
       .post_id(post_without_matching_comment.id)
       .create
 
-    posts = Post::BaseQuery.new.right_join_comments.where_comments(&.body.eq("matching"))
+    posts = Post::BaseQuery.new
+      .right_join_comments
+      .where_comments(Comment::BaseQuery.new.body.eq("matching"), auto_inner_join: false)
     posts.to_sql[0].should contain "RIGHT JOIN"
     posts.results.should eq([post_with_matching_comment])
   end
@@ -98,7 +113,9 @@ describe "Query associations" do
       .post_id(post_without_matching_comment.id)
       .create
 
-    posts = Post::BaseQuery.new.full_join_comments.where_comments(&.body.eq("matching"))
+    posts = Post::BaseQuery.new
+      .full_join_comments
+      .where_comments(Comment::BaseQuery.new.body.eq("matching"), auto_inner_join: false)
     posts.to_sql[0].should contain "FULL JOIN"
     posts.results.should eq([post_with_matching_comment])
   end

src/avram/associations/has_many.cr

@@ -37,7 +37,7 @@ module Avram::Associations::HasMany
             all_{{ assoc_name }} = preload_query
               .dup
               .join_{{ through.id }}
-              .where_{{ through.id }} do |through_query|
+              .__yield_where_{{ through.id }} do |through_query|
                 through_query.{{ foreign_key.id }}.in(ids)
               end
               .preload_{{ through.id }}
@@ -90,7 +90,7 @@ module Avram::Associations::HasMany
         {{ model }}::BaseQuery
           .new
           .join_{{ through.id }}
-          .where_{{ through.id }} do |through_query|
+          .__yield_where_{{ through.id }} do |through_query|
             through_query.{{ foreign_key.id }}(id)
           end
           .preload_{{ through.id }}

src/avram/base_query_template.cr

@@ -68,7 +68,7 @@ class Avram::BaseQueryTemplate
               )
             {% elsif assoc[:through] %}
               {{ join_type.downcase.id }}_join_{{ assoc[:through].id }}
-              where_{{ assoc[:through].id }} do |join_query|
+              __yield_where_{{ assoc[:through].id }} do |join_query|
                 join_query.{{ join_type.downcase.id }}_join_{{ assoc[:table_name] }}
               end
             {% else %}
@@ -85,20 +85,30 @@ class Avram::BaseQueryTemplate
         {% end %}
 
 
-        def where_{{ assoc[:table_name] }}
-          {{ assoc[:type] }}::BaseQuery.new_with_existing_query(query).tap do |assoc_query|
-            yield assoc_query
-          end
+        def where_{{ assoc[:table_name] }}(assoc_query : ::{{ assoc[:type] }}::BaseQuery, auto_inner_join : Bool = true)
+          join_{{ assoc[:table_name] }} if auto_inner_join
+          query.merge(assoc_query.query)
+          self
+        end
+
+        # :nodoc:
+        # Used internally for has_many throuogh queries
+        def __yield_where_{{ assoc[:table_name] }}
+          assoc_query = yield {{ assoc[:type] }}::BaseQuery.new
+          query.merge(assoc_query.query)
           self
         end
 
         def {{ assoc[:table_name] }}
           \{% raise <<-ERROR
-            The methods for querying associations are now prefixed with 'where_'
+            The methods for querying associations have changed
+
+              * They are now prefixed with 'where_'.
+              * The query is no longer yielded. You must pass it explicitly.
 
-            Try this...
+            Example:
 
-              ▸ Use 'where_{{ assoc[:table_name] }}'
+              where_{{ assoc[:table_name] }}({{ assoc[:type] }}Query.new.some_condition)
             ERROR
           %}
           yield # This is not used. Just there so it works with blocks.