diff --git a/.github/workflows/continuous-integration.yaml b/.github/workflows/continuous-integration.yaml
index b7bce71255..cd4f52362b 100644
--- a/.github/workflows/continuous-integration.yaml
+++ b/.github/workflows/continuous-integration.yaml
@@ -2,7 +2,7 @@ name: 'Continuous integration'
 on: ['push', 'pull_request']
 jobs:
   cs:
-    runs-on: 'ubuntu-latest'
+    runs-on: 'ubuntu-20.04'
     name: 'Coding style'
     steps:
       - name: 'Checkout'
@@ -21,3 +21,53 @@ jobs:
 
       - name: 'Check composer.json'
         run: 'composer-normalize --diff --dry-run --indent-size=4 --indent-style=space --no-update-lock'
+
+  phpunit:
+    runs-on: 'ubuntu-20.04'
+    name: 'PHPUnit (PHP ${{ matrix.php }}, ES ${{ matrix.elasticsearch }})'
+    timeout-minutes: 5
+    strategy:
+      matrix:
+        include:
+          - php: '7.2'
+            elasticsearch: '7.1.1'
+          - php: '7.2'
+            elasticsearch: '7.2.1'
+          - php: '7.3'
+            elasticsearch: '7.3.2'
+          - php: '7.4'
+            elasticsearch: '7.3.2'
+          - php: '8.0'
+            elasticsearch: '7.3.2'
+            composer_flags: '--ignore-platform-reqs'
+      fail-fast: false
+    steps:
+      - name: 'Checkout'
+        uses: 'actions/checkout@v2'
+
+      - name: 'Setup PHP'
+        uses: 'shivammathur/setup-php@v2'
+        with:
+          php-version: '${{ matrix.php }}'
+          coverage: 'none'
+          tools: 'pecl, composer:v2'
+          extensions: 'curl, json, mbstring, openssl'
+
+      - name: 'Get composer cache directory'
+        id: 'composer_cache'
+        run: 'echo "::set-output name=dir::$(composer config cache-files-dir)"'
+
+      - name: 'Cache dependencies'
+        uses: 'actions/cache@v2'
+        with:
+          path: '${{ steps.composer_cache.outputs.dir }}'
+          key: '${{ runner.os }}-composer-php${{ matrix.php }}-${{ hashFiles(''**/composer.json'') }}'
+          restore-keys: |
+            ${{ runner.os }}-composer-php${{ matrix.php }}-
+            ${{ runner.os }}-composer-
+
+      - name: 'Update dependencies'
+        run: 'composer update --prefer-dist --no-interaction --no-progress --ansi ${{ matrix.composer_flags }}'
+
+      - name: 'Run tests'
+        run: 'vendor/bin/phpunit --group unit'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 606d96c643..ad47995bd8 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -44,6 +44,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Used new settings endpoints classes [#1852](https://github.com/ruflin/Elastica/pull/1852)
 * Allow float values for connection timeout and connection connect-timeout, providing ms precision for those. Previous precision was second. [#1868](https://github.com/ruflin/Elastica/pull/1868)
 * Run coding styles check on github action [#1878](https://github.com/ruflin/Elastica/pull/1878)
+* Run unit tests on github action [#1882](https://github.com/ruflin/Elastica/pull/1882)
 ### Deprecated
 * Deprecated `Elastica\Aggregation\Range::setKeyedResponse()`, use `setKeyed()` instead [#1848](https://github.com/ruflin/Elastica/pull/1848)
 * Deprecated `Elastica\Exception\ResponseException::getElasticsearchException()`, use `getResponse()::getFullError()` instead [#1829](https://github.com/ruflin/Elastica/pull/1829)
diff --git a/tests/Aggregation/TermsTest.php b/tests/Aggregation/TermsTest.php
index 6c1126bd0c..502343efbe 100644
--- a/tests/Aggregation/TermsTest.php
+++ b/tests/Aggregation/TermsTest.php
@@ -9,8 +9,6 @@
 use Elastica\Query;
 
 /**
- * @group functional
- *
  * @internal
  */
 class TermsTest extends BaseAggregationTest
@@ -73,6 +71,9 @@ public function testExcludeExactMatch(): void
         $this->assertSame(['first', 'second'], $agg->getParam('exclude'));
     }
 
+    /**
+     * @group functional
+     */
     public function testTermsAggregation(): void
     {
         $agg = new Terms('terms');
@@ -86,6 +87,9 @@ public function testTermsAggregation(): void
         $this->assertEquals('blue', $results['buckets'][0]['key']);
     }
 
+    /**
+     * @group functional
+     */
     public function testTermsSetOrder(): void
     {
         $agg = new Terms('terms');
@@ -99,6 +103,9 @@ public function testTermsSetOrder(): void
         $this->assertEquals('blue', $results['buckets'][2]['key']);
     }
 
+    /**
+     * @group functional
+     */
     public function testTermsSetOrders(): void
     {
         $agg = new Terms('terms');
diff --git a/tests/Base.php b/tests/Base.php
index df144a77f4..a9ad2c0e48 100644
--- a/tests/Base.php
+++ b/tests/Base.php
@@ -186,20 +186,20 @@ protected function _isUnitGroup()
     {
         $groups = TestUtil::getGroups(\get_class($this), $this->getName(false));
 
-        return \in_array('unit', $groups);
+        return \in_array('unit', $groups, true);
     }
 
     protected function _isFunctionalGroup()
     {
         $groups = TestUtil::getGroups(\get_class($this), $this->getName(false));
 
-        return \in_array('functional', $groups);
+        return \in_array('functional', $groups, true);
     }
 
     protected function _isBenchmarkGroup()
     {
         $groups = TestUtil::getGroups(\get_class($this), $this->getName(false));
 
-        return \in_array('benchmark', $groups);
+        return \in_array('benchmark', $groups, true);
     }
 }
diff --git a/tests/BasePipeline.php b/tests/BasePipeline.php
index beac80f36c..6d0b10c2dc 100644
--- a/tests/BasePipeline.php
+++ b/tests/BasePipeline.php
@@ -12,7 +12,10 @@ class BasePipeline extends BaseTest
 {
     protected function tearDown(): void
     {
-        $this->_createPipeline()->deletePipeline('*');
+        if ($this->_isFunctionalGroup()) {
+            $this->_createPipeline()->deletePipeline('*');
+        }
+
         parent::tearDown();
     }
 
diff --git a/tests/IndexTest.php b/tests/IndexTest.php
index ca72d974fc..7a2380cae4 100644
--- a/tests/IndexTest.php
+++ b/tests/IndexTest.php
@@ -2,6 +2,7 @@
 
 namespace Elastica\Test;
 
+use Elastica\Client;
 use Elastica\Document;
 use Elastica\Exception\InvalidException;
 use Elastica\Exception\ResponseException;
@@ -18,14 +19,15 @@
 use Symfony\Bridge\PhpUnit\ExpectDeprecationTrait;
 
 /**
- * @group functional
- *
  * @internal
  */
 class IndexTest extends BaseTest
 {
     use ExpectDeprecationTrait;
 
+    /**
+     * @group functional
+     */
     public function testMapping(): void
     {
         $index = $this->_createIndex();
@@ -51,6 +53,9 @@ public function testMapping(): void
         $this->assertEquals('integer', $storedMapping['properties']['test']['type']);
     }
 
+    /**
+     * @group functional
+     */
     public function testGetMappingAlias(): void
     {
         $index = $this->_createIndex();
@@ -77,6 +82,9 @@ public function testGetMappingAlias(): void
         $this->assertEquals($mapping1, $mapping2);
     }
 
+    /**
+     * @group functional
+     */
     public function testAddRemoveAlias(): void
     {
         $this->expectException(ResponseException::class);
@@ -115,6 +123,9 @@ public function testAddRemoveAlias(): void
         $client->getIndex($aliasName)->search('ruflin');
     }
 
+    /**
+     * @group functional
+     */
     public function testCount(): void
     {
         $index = $this->_createIndex();
@@ -138,6 +149,9 @@ public function testCount(): void
         $this->assertEquals(1, $index->count($query));
     }
 
+    /**
+     * @group functional
+     */
     public function testCountGet(): void
     {
         $index = $this->_createIndex();
@@ -161,6 +175,9 @@ public function testCountGet(): void
         $this->assertEquals(1, $index->count($query, Request::GET));
     }
 
+    /**
+     * @group functional
+     */
     public function testDeleteByQueryWithQueryString(): void
     {
         $index = $this->_createIndex();
@@ -190,6 +207,9 @@ public function testDeleteByQueryWithQueryString(): void
         $this->assertEquals(0, $response->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testDeleteByQueryWithQuery(): void
     {
         $index = $this->_createIndex();
@@ -219,6 +239,9 @@ public function testDeleteByQueryWithQuery(): void
         $this->assertEquals(0, $response->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testDeleteByQueryWithArrayQuery(): void
     {
         $index = $this->_createIndex();
@@ -248,6 +271,9 @@ public function testDeleteByQueryWithArrayQuery(): void
         $this->assertEquals(0, $response->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testDeleteByQueryWithQueryAndOptions(): void
     {
         $index = $this->_createIndex(null, true, 2);
@@ -304,6 +330,9 @@ public function testDeleteByQueryWithQueryAndOptions(): void
         $this->assertEquals(0, $response->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testUpdateByQueryWithQueryString(): void
     {
         $index = $this->_createIndex();
@@ -336,6 +365,9 @@ public function testUpdateByQueryWithQueryString(): void
         $this->assertEquals(0, $response->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testUpdateByQueryAll(): void
     {
         $index = $this->_createIndex();
@@ -368,6 +400,9 @@ public function testUpdateByQueryAll(): void
         $this->assertEquals(0, $response->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testDeleteIndexDeleteAlias(): void
     {
         $indexName = 'test';
@@ -393,6 +428,9 @@ public function testDeleteIndexDeleteAlias(): void
         $this->assertFalse($status->aliasExists($aliasName));
     }
 
+    /**
+     * @group functional
+     */
     public function testAddAliasTwoIndices(): void
     {
         $indexName1 = 'test1';
@@ -418,6 +456,9 @@ public function testAddAliasTwoIndices(): void
         $this->assertTrue($index1->hasAlias($aliasName));
     }
 
+    /**
+     * @group functional
+     */
     public function testReplaceAlias(): void
     {
         $indexName1 = 'test1';
@@ -440,6 +481,9 @@ public function testReplaceAlias(): void
         $this->assertTrue($index1->hasAlias($aliasName));
     }
 
+    /**
+     * @group functional
+     */
     public function testAddDocumentVersion(): void
     {
         $client = $this->_getClient();
@@ -460,6 +504,9 @@ public function testAddDocumentVersion(): void
         $this->assertEquals(2, $data['_version']);
     }
 
+    /**
+     * @group functional
+     */
     public function testClearCache(): void
     {
         $index = $this->_createIndex();
@@ -467,6 +514,9 @@ public function testClearCache(): void
         $this->assertFalse($response->hasError());
     }
 
+    /**
+     * @group functional
+     */
     public function testFlush(): void
     {
         $index = $this->_createIndex();
@@ -474,6 +524,9 @@ public function testFlush(): void
         $this->assertFalse($response->hasError());
     }
 
+    /**
+     * @group functional
+     */
     public function testExists(): void
     {
         $index = $this->_createIndex();
@@ -491,6 +544,8 @@ public function testExists(): void
      * Tests if deleting an index that does not exist in Elasticsearch,
      * correctly returns a boolean true from the hasError() method of
      * the \Elastica\Response object
+     *
+     * @group functional
      */
     public function testDeleteMissingIndexHasError(): void
     {
@@ -510,6 +565,8 @@ public function testDeleteMissingIndexHasError(): void
 
     /**
      * Tests to see if the test type mapping exists when calling $index->getMapping().
+     *
+     * @group functional
      */
     public function testIndexGetMapping(): void
     {
@@ -532,6 +589,9 @@ public function testIndexGetMapping(): void
         $this->assertEquals('integer', $indexMappings['properties']['test']['type']);
     }
 
+    /**
+     * @group functional
+     */
     public function testEmptyIndexGetMapping(): void
     {
         $indexMappings = $this->_createIndex()->getMapping();
@@ -541,6 +601,8 @@ public function testEmptyIndexGetMapping(): void
 
     /**
      * Test to see if search Default Limit works.
+     *
+     * @group functional
      */
     public function testLimitDefaultIndex(): void
     {
@@ -626,17 +688,19 @@ public function testCreateWithInvalidOption(): void
         $this->expectException(InvalidException::class);
         $this->expectExceptionMessageMatches('/"testing_invalid_option" is not a valid option\. Allowed options are ((("[a-z_]+")(, )?)+)\./');
 
-        $client = $this->_getClient();
-        $indexName = 'test';
-        $index = $client->getIndex($indexName);
+        $client = $this->createMock(Client::class);
+        $index = new Index($client, 'test');
 
         $opts = ['testing_invalid_option' => true];
         $index->create([], $opts);
     }
 
+    /**
+     * @group unit
+     */
     public function testCreateSearch(): void
     {
-        $client = $this->_getClient();
+        $client = $this->createMock(Client::class);
         $index = new Index($client, 'test');
 
         $query = new QueryString('test');
@@ -659,6 +723,9 @@ public function testCreateSearch(): void
         $this->assertTrue($search->hasIndex($index));
     }
 
+    /**
+     * @group functional
+     */
     public function testSearch(): void
     {
         $index = $this->_createIndex();
@@ -686,6 +753,9 @@ public function testSearch(): void
         $this->assertEquals(3, $count);
     }
 
+    /**
+     * @group functional
+     */
     public function testSearchGet(): void
     {
         $index = $this->_createIndex();
@@ -701,6 +771,9 @@ public function testSearchGet(): void
         $this->assertEquals(1, $count);
     }
 
+    /**
+     * @group functional
+     */
     public function testForcemerge(): void
     {
         $index = $this->_createIndex('testforcemerge_indextest', false, 3);
@@ -728,6 +801,9 @@ public function testForcemerge(): void
         $this->assertEquals(0, $stats['_all']['primaries']['docs']['deleted']);
     }
 
+    /**
+     * @group functional
+     */
     public function testAnalyze(): void
     {
         $index = $this->_createIndex();
@@ -747,6 +823,9 @@ public function testAnalyze(): void
         $this->assertEquals($tokens, $returnedTokens);
     }
 
+    /**
+     * @group functional
+     */
     public function testRequestEndpoint(): void
     {
         $index = $this->_createIndex();
@@ -769,6 +848,9 @@ public function testRequestEndpoint(): void
         $this->assertEquals($tokens, $returnedTokens);
     }
 
+    /**
+     * @group functional
+     */
     public function testAnalyzeExplain(): void
     {
         $index = $this->_createIndex();
@@ -778,6 +860,9 @@ public function testAnalyzeExplain(): void
         $this->assertArrayHasKey('custom_analyzer', $data);
     }
 
+    /**
+     * @group functional
+     */
     public function testGetEmptyAliases(): void
     {
         $indexName = 'test-getaliases';
diff --git a/tests/PipelineTest.php b/tests/PipelineTest.php
index b6488f78e1..16fb3208a4 100644
--- a/tests/PipelineTest.php
+++ b/tests/PipelineTest.php
@@ -3,6 +3,7 @@
 namespace Elastica\Test;
 
 use Elastica\Bulk;
+use Elastica\Client;
 use Elastica\Document;
 use Elastica\Exception\ResponseException;
 use Elastica\Pipeline;
@@ -24,7 +25,8 @@ public function testProcessor(): void
         $rename = new Rename('foo', 'target.field');
         $set = new Set('field4', 324);
 
-        $processors = new Pipeline($this->_getClient());
+        $client = $this->createMock(Client::class);
+        $processors = new Pipeline($client);
         $processors->setDescription('this is a new pipeline');
         $processors->addProcessor($trim);
         $processors->addProcessor($rename);
diff --git a/tests/Processor/AttachmentTest.php b/tests/Processor/AttachmentTest.php
index 47cca66a4e..26a800441d 100644
--- a/tests/Processor/AttachmentTest.php
+++ b/tests/Processor/AttachmentTest.php
@@ -9,8 +9,6 @@
 use Elastica\Test\BasePipeline as BasePipelineTest;
 
 /**
- * @group functional
- *
  * @internal
  */
 class AttachmentTest extends BasePipelineTest
@@ -55,6 +53,9 @@ public function testAttachmentWithNonDefaultOptions(): void
         $this->assertEquals($expected, $processor->toArray());
     }
 
+    /**
+     * @group functional
+     */
     public function testAttachmentAddPdf(): void
     {
         $attachment = new Attachment('data');
@@ -94,6 +95,9 @@ public function testAttachmentAddPdf(): void
         $this->assertEquals(0, $resultSet->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testAttachmentAddPdfFileContent(): void
     {
         $attachment = new Attachment('data');
@@ -136,6 +140,9 @@ public function testAttachmentAddPdfFileContent(): void
         $this->assertEquals(0, $resultSet->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testAddWordxFile(): void
     {
         $attachment = new Attachment('data');
@@ -176,6 +183,9 @@ public function testAddWordxFile(): void
         $this->assertEquals(0, $resultSet->count());
     }
 
+    /**
+     * @group functional
+     */
     public function testExcludeFileSource(): void
     {
         $attachment = new Attachment('data');
diff --git a/tests/Query/ParentIdTest.php b/tests/Query/ParentIdTest.php
index 51eb9a661d..70caf8abfb 100644
--- a/tests/Query/ParentIdTest.php
+++ b/tests/Query/ParentIdTest.php
@@ -124,7 +124,7 @@ public function testParentId(): void
     }
 
     /**
-     * @group unit
+     * @group functional
      */
     public function testQueryBuilderParentId(): void
     {
diff --git a/tests/Query/PercolateTest.php b/tests/Query/PercolateTest.php
index fb621d77cd..e8587930b3 100644
--- a/tests/Query/PercolateTest.php
+++ b/tests/Query/PercolateTest.php
@@ -2,7 +2,9 @@
 
 namespace Elastica\Test\Query;
 
+use Elastica\Client;
 use Elastica\Document;
+use Elastica\Index;
 use Elastica\Mapping;
 use Elastica\Query\Percolate;
 use Elastica\Test\Base as BaseTest;
@@ -131,7 +133,8 @@ public function testSetDocument(): void
      */
     public function testSetDocumentIndex(): void
     {
-        $index = $this->_createIndex('indexone');
+        $client = $this->createMock(Client::class);
+        $index = new Index($client, 'indexone');
         $query = new Percolate();
         $query->setDocumentIndex($index->getName());
 
diff --git a/tests/Query/TermsTest.php b/tests/Query/TermsTest.php
index 7d6ae773bd..2d1ee57032 100644
--- a/tests/Query/TermsTest.php
+++ b/tests/Query/TermsTest.php
@@ -9,10 +9,12 @@
 
 /**
  * @internal
- * @group unit
  */
 class TermsTest extends BaseTest
 {
+    /**
+     * @group unit
+     */
     public function testSetTermsLookup(): void
     {
         $terms = [
@@ -28,6 +30,9 @@ public function testSetTermsLookup(): void
         $this->assertEquals($terms, $data['terms']['name']);
     }
 
+    /**
+     * @group unit
+     */
     public function testInvalidParams(): void
     {
         $query = new Terms('field', ['aaa', 'bbb']);
@@ -37,6 +42,9 @@ public function testInvalidParams(): void
         $query->toArray();
     }
 
+    /**
+     * @group unit
+     */
     public function testEmptyField(): void
     {
         $this->expectException(InvalidException::class);
@@ -176,6 +184,9 @@ public function testVariousDataTypesViaAddTerm(): void
         $this->assertEquals(1, $resultSet->count());
     }
 
+    /**
+     * @group unit
+     */
     public function testAddTermTypeError(): void
     {
         $this->expectException(\TypeError::class);