diff --git a/elasticsearch-api/README.md b/elasticsearch-api/README.md
index 30d4489ed6..7c175ebcac 100644
--- a/elasticsearch-api/README.md
+++ b/elasticsearch-api/README.md
@@ -15,7 +15,9 @@ Language clients are forward compatible; meaning that clients support communicat
 
 Refer to [CONTRIBUTING](https://github.com/elastic/elasticsearch-ruby/blob/main/CONTRIBUTING.md).
 
-The integration tests on this project run the [Elasticsearch Client tests](https://github.com/elastic/elasticsearch-clients-tests/) with the [Elasticsearch Tests Runner](https://github.com/elastic/es-test-runner-ruby/) library. This runs in CI against an Elasticsearch cluster in Docker. You can run a docker container with Elasticsearch with a Rake task from the root directory of this project:
+Use `bundle exec rake test:unit` to run Unit tests. Add the environment variable `COVERAGE` to see Simplecov test coverage.
+
+The integration tests on this project run the [Elasticsearch Client tests](https://github.com/elastic/elasticsearch-clients-tests/) with the [Elasticsearch Tests Runner](https://github.com/elastic/es-test-runner-ruby/) library. You can run a docker container with Elasticsearch with a Rake task from the root directory of this project:
 
 ```bash
 $ rake es:up
@@ -27,6 +29,8 @@ This will start whatever version of Elasticsearch is set in the Buildkite pipeli
 $ rake es:start[version,suite] # e.g. rake es:start[9.0.0-SNAPSHOT, free]
 ```
 
+You can run the integration tests with `bundle exec rake test:integration`.
+
 ### Code generation
 
 The code for most of this library is automatically generated. See [./utils/README.md](utils/README.md) for more information.
diff --git a/elasticsearch-api/Rakefile b/elasticsearch-api/Rakefile
index 1583729010..6c6fa4fcf7 100644
--- a/elasticsearch-api/Rakefile
+++ b/elasticsearch-api/Rakefile
@@ -35,7 +35,6 @@ namespace :test do
   task :unit
   RSpec::Core::RakeTask.new(:unit) do |t|
     t.pattern = 'spec/unit/**/*_spec.rb'
-    t.ruby_opts = '-W0'
   end
 
   desc 'Run unit and integration tests'
@@ -52,7 +51,6 @@ namespace :test do
   desc 'Run Integration tests'
   RSpec::Core::RakeTask.new(:integration) do |t|
     t.pattern = 'spec/integration/**/*_spec.rb'
-    t.ruby_opts = '-W0'
   end
 
   # This is the task to run the Elasticsearch REST tests which we stopped using for 9.x.
diff --git a/elasticsearch-api/spec/integration/api_key_spec.rb b/elasticsearch-api/spec/integration/api_key_spec.rb
index 55c9d977af..f2453dc76a 100644
--- a/elasticsearch-api/spec/integration/api_key_spec.rb
+++ b/elasticsearch-api/spec/integration/api_key_spec.rb
@@ -18,7 +18,7 @@
 # under the License.
 
 require 'base64'
-require_relative './spec_helper'
+require_relative './integration_helper'
 
 describe 'API keys' do
   before do
diff --git a/elasticsearch-api/spec/integration/health_spec.rb b/elasticsearch-api/spec/integration/health_spec.rb
index 8abad8dcc7..3f7207094d 100644
--- a/elasticsearch-api/spec/integration/health_spec.rb
+++ b/elasticsearch-api/spec/integration/health_spec.rb
@@ -17,7 +17,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
-require_relative './spec_helper'
+require_relative './integration_helper'
 
 describe 'Health basic test' do
   it 'performs the request' do
diff --git a/elasticsearch-api/spec/integration/spec_helper.rb b/elasticsearch-api/spec/integration/integration_helper.rb
similarity index 100%
rename from elasticsearch-api/spec/integration/spec_helper.rb
rename to elasticsearch-api/spec/integration/integration_helper.rb
diff --git a/elasticsearch-api/spec/spec_helper.rb b/elasticsearch-api/spec/spec_helper.rb
index b7c649670b..420a4aecd3 100644
--- a/elasticsearch-api/spec/spec_helper.rb
+++ b/elasticsearch-api/spec/spec_helper.rb
@@ -14,9 +14,12 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-if ENV['COVERAGE'] && ENV['CI'].nil?
+if ENV['COVERAGE']
   require 'simplecov'
-  SimpleCov.start { add_filter %r{^/test|spec/} }
+  SimpleCov.start do
+    add_filter %r{^/test|spec/}
+    add_filter 'utils/thor'
+  end
 end
 
 if defined?(JRUBY_VERSION)
diff --git a/elasticsearch-api/spec/unit/actions/hashie_spec.rb b/elasticsearch-api/spec/unit/actions/hashie_spec.rb
index 6081a21dd9..afba03698f 100644
--- a/elasticsearch-api/spec/unit/actions/hashie_spec.rb
+++ b/elasticsearch-api/spec/unit/actions/hashie_spec.rb
@@ -17,9 +17,10 @@
 
 require 'spec_helper'
 require 'hashie'
+require 'hashie/logger'
+Hashie.logger = Logger.new(nil)
 
 describe 'Hashie' do
-
   let(:json) do
     <<-JSON
             {
@@ -79,7 +80,7 @@
   end
 
   let(:response) do
-    Hashie::Mash.new MultiJson.load(json)
+    Hashie::Mash.new(MultiJson.load(json))
   end
 
   it 'wraps the response' do
diff --git a/elasticsearch-api/spec/unit/actions/nodes/info_spec.rb b/elasticsearch-api/spec/unit/actions/nodes/info_spec.rb
index ad677be08d..8f69b9f5ca 100644
--- a/elasticsearch-api/spec/unit/actions/nodes/info_spec.rb
+++ b/elasticsearch-api/spec/unit/actions/nodes/info_spec.rb
@@ -18,15 +18,14 @@
 require 'spec_helper'
 
 describe 'client.nodes#info' do
-
   let(:expected_args) do
     [
-        'GET',
-        url,
-        params,
-        nil,
-        {},
-        { endpoint: 'nodes.info' }
+      'GET',
+      url,
+      params,
+      nil,
+      {},
+      { endpoint: 'nodes.info' }
     ]
   end
 
@@ -43,7 +42,6 @@
   end
 
   context 'when the node id is specified' do
-
     let(:url) do
       '_nodes/foo'
     end
@@ -65,7 +63,6 @@
   end
 
   context 'when multiple node ids are specified as a list' do
-
     let(:url) do
       '_nodes/A,B,C'
     end
@@ -87,7 +84,6 @@
   end
 
   context 'when multiple node ids are specified as a String' do
-
     let(:url) do
       '_nodes/A,B,C'
     end
@@ -109,7 +105,6 @@
   end
 
   context 'when URL params are specified' do
-
     let(:url) do
       '_nodes'
     end
@@ -124,7 +119,6 @@
   end
 
   context 'when metrics are specified' do
-
     let(:url) do
       '_nodes/http,network'
     end
diff --git a/elasticsearch-api/spec/unit/actions/nodes/usage_spec.rb b/elasticsearch-api/spec/unit/actions/nodes/usage_spec.rb
new file mode 100644
index 0000000000..25824cd7c5
--- /dev/null
+++ b/elasticsearch-api/spec/unit/actions/nodes/usage_spec.rb
@@ -0,0 +1,106 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+require 'spec_helper'
+
+describe 'client.nodes#usage' do
+  let(:expected_args) do
+    [
+      'GET',
+      url,
+      params,
+      nil,
+      {},
+      { endpoint: 'nodes.usage' }
+    ]
+  end
+
+  let(:url) do
+    '_nodes/usage'
+  end
+
+  it 'performs the request' do
+    expect(client_double.nodes.usage).to be_a Elasticsearch::API::Response
+  end
+
+  let(:params) do
+    {}
+  end
+
+  context 'when the node id is specified' do
+    let(:url) do
+      '_nodes/foo/usage'
+    end
+
+    let(:expected_args) do
+      [
+        'GET',
+        url,
+        params,
+        nil,
+        {},
+        { defined_params: { node_id: 'foo' }, endpoint: 'nodes.usage' }
+      ]
+    end
+
+    it 'performs the request' do
+      expect(client_double.nodes.usage(node_id: 'foo')).to be_a Elasticsearch::API::Response
+    end
+  end
+
+  context 'when the metric is specified' do
+    let(:url) do
+      '_nodes/usage/metric'
+    end
+
+    let(:expected_args) do
+      [
+        'GET',
+        url,
+        params,
+        nil,
+        {},
+        { defined_params: { metric: 'metric' }, endpoint: 'nodes.usage' }
+      ]
+    end
+
+    it 'performs the request' do
+      expect(client_double.nodes.usage(metric: 'metric')).to be_a Elasticsearch::API::Response
+    end
+  end
+
+  context 'when both are specified' do
+    let(:url) do
+      '_nodes/foo/usage/metric'
+    end
+
+    let(:expected_args) do
+      [
+        'GET',
+        url,
+        params,
+        nil,
+        {},
+        { defined_params: { node_id: 'foo', metric: 'metric' }, endpoint: 'nodes.usage' }
+      ]
+    end
+
+    it 'performs the request' do
+      expect(client_double.nodes.usage(metric: 'metric', node_id: 'foo')).to be_a Elasticsearch::API::Response
+    end
+  end
+end
diff --git a/elasticsearch-api/spec/unit/actions/termvectors_spec.rb b/elasticsearch-api/spec/unit/actions/termvectors_spec.rb
index 86e2ad33ba..d7d607832f 100644
--- a/elasticsearch-api/spec/unit/actions/termvectors_spec.rb
+++ b/elasticsearch-api/spec/unit/actions/termvectors_spec.rb
@@ -72,7 +72,11 @@
     end
 
     it 'performs the request' do
-      expect(client_double.termvector(index: 'foo', id: '123', body: {})).to be_a Elasticsearch::API::Response
+      message = '[DEPRECATION] `termvector` is deprecated. Please use the plural version, `termvectors` instead.
+'
+      expect do
+        client_double.termvector(index: 'foo', id: '123', body: {})
+      end.to output(message).to_stderr
     end
   end
 end
diff --git a/elasticsearch-api/spec/unit/api_response_spec.rb b/elasticsearch-api/spec/unit/api_response_spec.rb
index c976602bb8..06fdb602ad 100644
--- a/elasticsearch-api/spec/unit/api_response_spec.rb
+++ b/elasticsearch-api/spec/unit/api_response_spec.rb
@@ -62,4 +62,8 @@
   it 'returns the body which' do
     expect(response.body).to eq response_body
   end
+
+  it 'returns the body with to_s' do
+    expect(response.to_s).to eq response.body.to_s
+  end
 end