diff --git a/src/plugins/data/server/search/es_search/es_search_service.test.ts b/src/plugins/data/server/search/es_search/es_search_service.test.ts
new file mode 100644
index 0000000000000..faf9487159c15
--- /dev/null
+++ b/src/plugins/data/server/search/es_search/es_search_service.test.ts
@@ -0,0 +1,60 @@
+/*
+ * 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.
+ */
+
+import { coreMock } from '../../../../../core/server/mocks';
+import { EsSearchService } from './es_search_service';
+import { PluginInitializerContext } from '../../../../../core/server';
+import { searchSetupMock } from '../mocks';
+
+describe('ES search strategy service', () => {
+  let service: EsSearchService;
+
+  const mockCoreSetup = coreMock.createSetup();
+  const opaqueId = Symbol();
+  const context: PluginInitializerContext = {
+    opaqueId,
+    config: {
+      createIfExists: jest.fn(),
+      create: jest.fn(),
+    },
+    env: {
+      mode: {
+        dev: false,
+        name: 'development',
+        prod: false,
+      },
+    },
+    logger: {
+      get: jest.fn(),
+    },
+  };
+
+  beforeEach(() => {
+    service = new EsSearchService(context);
+  });
+
+  describe('setup()', () => {
+    it('registers the ES search strategy', async () => {
+      service.setup(mockCoreSetup, {
+        search: searchSetupMock,
+      });
+      expect(searchSetupMock.registerSearchStrategyProvider).toBeCalled();
+    });
+  });
+});
diff --git a/src/plugins/data/server/search/es_search/es_search_strategy.test.ts b/src/plugins/data/server/search/es_search/es_search_strategy.test.ts
new file mode 100644
index 0000000000000..619a28df839bd
--- /dev/null
+++ b/src/plugins/data/server/search/es_search/es_search_strategy.test.ts
@@ -0,0 +1,102 @@
+/*
+ * 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.
+ */
+
+import { coreMock } from '../../../../../core/server/mocks';
+import { esSearchStrategyProvider } from './es_search_strategy';
+
+describe('ES search strategy', () => {
+  const mockCoreSetup = coreMock.createSetup();
+  const mockApiCaller = jest.fn().mockResolvedValue({
+    _shards: {
+      total: 10,
+      failed: 1,
+      skipped: 2,
+      successful: 7,
+    },
+  });
+  const mockSearch = jest.fn();
+
+  beforeEach(() => {
+    mockApiCaller.mockClear();
+    mockSearch.mockClear();
+  });
+
+  it('returns a strategy with `search`', () => {
+    const esSearch = esSearchStrategyProvider(
+      {
+        core: mockCoreSetup,
+      },
+      mockApiCaller,
+      mockSearch
+    );
+
+    expect(typeof esSearch.search).toBe('function');
+  });
+
+  it('logs the response if `debug` is set to `true`', () => {
+    const spy = jest.spyOn(console, 'log');
+    const esSearch = esSearchStrategyProvider(
+      {
+        core: mockCoreSetup,
+      },
+      mockApiCaller,
+      mockSearch
+    );
+
+    expect(spy).not.toBeCalled();
+
+    esSearch.search({ params: {}, debug: true });
+
+    expect(spy).toBeCalled();
+  });
+
+  it('calls the API caller with the params', () => {
+    const params = { index: 'logstash-*' };
+    const esSearch = esSearchStrategyProvider(
+      {
+        core: mockCoreSetup,
+      },
+      mockApiCaller,
+      mockSearch
+    );
+
+    esSearch.search({ params });
+
+    expect(mockApiCaller).toBeCalled();
+    expect(mockApiCaller.mock.calls[0][0]).toBe('search');
+    expect(mockApiCaller.mock.calls[0][1]).toEqual(params);
+  });
+
+  it('returns total, loaded, and raw response', async () => {
+    const params = { index: 'logstash-*' };
+    const esSearch = esSearchStrategyProvider(
+      {
+        core: mockCoreSetup,
+      },
+      mockApiCaller,
+      mockSearch
+    );
+
+    const response = await esSearch.search({ params });
+
+    expect(response).toHaveProperty('total');
+    expect(response).toHaveProperty('loaded');
+    expect(response).toHaveProperty('rawResponse');
+  });
+});
diff --git a/src/plugins/data/server/search/mocks.ts b/src/plugins/data/server/search/mocks.ts
index ac585363495c6..136e7a1d580c9 100644
--- a/src/plugins/data/server/search/mocks.ts
+++ b/src/plugins/data/server/search/mocks.ts
@@ -20,5 +20,7 @@
 export const searchSetupMock = {
   registerSearchStrategyContext: jest.fn(),
   registerSearchStrategyProvider: jest.fn(),
-  __LEGACY: jest.fn(),
+  __LEGACY: {
+    search: jest.fn(),
+  },
 };
diff --git a/src/plugins/data/server/search/routes.test.ts b/src/plugins/data/server/search/routes.test.ts
new file mode 100644
index 0000000000000..0923b52565097
--- /dev/null
+++ b/src/plugins/data/server/search/routes.test.ts
@@ -0,0 +1,99 @@
+/*
+ * 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.
+ */
+
+import { httpServiceMock, httpServerMock } from '../../../../../src/core/server/mocks';
+import { registerSearchRoute } from './routes';
+import { IRouter, ScopedClusterClient } from 'kibana/server';
+
+describe('Search service', () => {
+  let routerMock: jest.Mocked<IRouter>;
+
+  beforeEach(() => {
+    routerMock = httpServiceMock.createRouter();
+  });
+
+  it('registers a post route', async () => {
+    registerSearchRoute(routerMock);
+    expect(routerMock.post).toBeCalled();
+  });
+
+  it('handler calls context.search.search with the given request and strategy', async () => {
+    const mockSearch = jest.fn().mockResolvedValue('yay');
+    const mockContext = {
+      core: {
+        elasticsearch: {
+          dataClient: {} as ScopedClusterClient,
+          adminClient: {} as ScopedClusterClient,
+        },
+      },
+      search: {
+        search: mockSearch,
+      },
+    };
+    const mockBody = { params: {} };
+    const mockParams = { strategy: 'foo' };
+    const mockRequest = httpServerMock.createKibanaRequest({
+      body: mockBody,
+      params: mockParams,
+    });
+    const mockResponse = httpServerMock.createResponseFactory();
+
+    registerSearchRoute(routerMock);
+    const handler = routerMock.post.mock.calls[0][1];
+    await handler(mockContext, mockRequest, mockResponse);
+
+    expect(mockSearch).toBeCalled();
+    expect(mockSearch.mock.calls[0][0]).toStrictEqual(mockBody);
+    expect(mockSearch.mock.calls[0][1]).toBe(mockParams.strategy);
+    expect(mockResponse.ok).toBeCalled();
+    expect(mockResponse.ok.mock.calls[0][0]).toEqual({ body: 'yay' });
+  });
+
+  it('handler throws internal error if the search throws an error', async () => {
+    const mockSearch = jest.fn().mockRejectedValue('oh no');
+    const mockContext = {
+      core: {
+        elasticsearch: {
+          dataClient: {} as ScopedClusterClient,
+          adminClient: {} as ScopedClusterClient,
+        },
+      },
+      search: {
+        search: mockSearch,
+      },
+    };
+    const mockBody = { params: {} };
+    const mockParams = { strategy: 'foo' };
+    const mockRequest = httpServerMock.createKibanaRequest({
+      body: mockBody,
+      params: mockParams,
+    });
+    const mockResponse = httpServerMock.createResponseFactory();
+
+    registerSearchRoute(routerMock);
+    const handler = routerMock.post.mock.calls[0][1];
+    await handler(mockContext, mockRequest, mockResponse);
+
+    expect(mockSearch).toBeCalled();
+    expect(mockSearch.mock.calls[0][0]).toStrictEqual(mockBody);
+    expect(mockSearch.mock.calls[0][1]).toBe(mockParams.strategy);
+    expect(mockResponse.internalError).toBeCalled();
+    expect(mockResponse.internalError.mock.calls[0][0]).toEqual({ body: 'oh no' });
+  });
+});