Merge #567

567: Federated search added r=brunoocasali a=Nymuxyzo

# Pull Request

## Related issue
Fixes #558

## What does this PR do?
- Federated search added

## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?


Co-authored-by: André <[email protected]>
Co-authored-by: ellnix <[email protected]>

Author: 3 people

.code-samples.meilisearch.yaml

@@ -712,3 +712,8 @@ distinct_attribute_guide_distinct_parameter_1: |-
   client.index('products').search('white shirt', {
     distinct: 'sku'
   })
+multi_search_federated_1: |-
+  client.multi_search(
+    queries: [{ index_uid: 'movies', q: 'batman' }, { index_uid: 'comics', q: 'batman' }],
+    federation: {}
+  )

lib/meilisearch/multi_search.rb

@@ -2,10 +2,20 @@
 
 module Meilisearch
   module MultiSearch
-    def multi_search(data)
-      body = Utils.transform_attributes(data)
+    # Performs search on one or more indexes
+    #
+    # @param [Hash] federation_options
+    #   - `limit`: number of results in the merged list
+    #   - `offset`: number of results to skip in the merged list
+    def multi_search(data = nil, queries: [], federation: nil)
+      Utils.soft_deprecate('multi_search([])', 'multi_search(queries: [])') if data
 
-      http_post '/multi-search', queries: body
+      queries += data if data
+
+      queries = Utils.transform_attributes(queries)
+      federation = Utils.transform_attributes(federation)
+
+      http_post '/multi-search', queries: queries, federation: federation
     end
   end
 end

spec/meilisearch/client/multi_search_spec.rb

@@ -7,7 +7,7 @@
   end
 
   it 'does a custom search with two different indexes' do
-    response = client.multi_search([
+    response = client.multi_search(queries: [
                                      { index_uid: 'books', q: 'prince' },
                                      { index_uid: 'movies', q: 'prince' }
                                    ])
@@ -16,4 +16,63 @@
     expect(response['results'][0]['estimatedTotalHits']).to eq(0)
     expect(response['results'][1]['estimatedTotalHits']).to eq(0)
   end
+
+  context 'when passed a positional argument' do
+    before { allow(Meilisearch::Utils).to receive(:soft_deprecate).and_return(nil) }
+
+    it 'does a custom search with two different indexes' do
+      response = client.multi_search([
+                                       { index_uid: 'books', q: 'prince' },
+                                       { index_uid: 'movies', q: 'prince' }
+                                     ])
+
+      expect(response['results'].count).to eq(2)
+      expect(response['results'][0]['estimatedTotalHits']).to eq(0)
+      expect(response['results'][1]['estimatedTotalHits']).to eq(0)
+    end
+
+    it 'warns about deprecation' do
+      client.multi_search([
+                            { index_uid: 'books', q: 'prince' },
+                            { index_uid: 'movies', q: 'prince' }
+                          ])
+
+      expect(Meilisearch::Utils).to have_received(:soft_deprecate)
+                                .with('multi_search([])', a_string_including('queries'))
+    end
+  end
+
+  it 'does a federated search with two different indexes' do
+    client.index('books').add_documents(
+      [
+        { id: 1, title: 'Harry Potter and the Philosophers Stone' },
+        { id: 2, title: 'War and Peace' },
+        { id: 5, title: 'Harry Potter and the Deathly Hallows' }
+      ]
+    )
+
+    client.index('movies').add_documents(
+      [
+        { id: 1, title: 'Harry Potter and the Philosophers Stone' },
+        { id: 2, title: 'Lord of the Rings' },
+        { id: 4, title: 'Harry Potter and the Order of the Phoenix' }
+      ]
+    ).await
+
+    response = client.multi_search(queries: [
+                                     { index_uid: 'books', q: 'Harry Potter' },
+                                     { index_uid: 'movies', q: 'Harry Potter' }
+                                   ],
+                                   federation: {
+                                     limit: 3,
+                                     offset: 1
+                                   })
+
+    expect(response['limit']).to eq(3)
+    expect(response['offset']).to eq(1)
+
+    hits = response['hits']
+    expect(hits.size).to be 3
+    expect(hits.first).to have_key('_federation')
+  end
 end