diff --git a/.github/workflows/test-application.yaml b/.github/workflows/test-application.yaml
index 722848bb..ecac1598 100644
--- a/.github/workflows/test-application.yaml
+++ b/.github/workflows/test-application.yaml
@@ -1,163 +1,177 @@
 name: Test application
 
 on:
-    pull_request:
-    push:
-        branches:
-            - '[0-9]+.[0-9]+'
-            - '[0-9]+.x'
+  pull_request:
+  push:
+    branches:
+      - '[0-9]+.[0-9]+'
+      - '[0-9]+.x'
 
 jobs:
-    code-style:
-      runs-on: ubuntu-latest
-
-      steps:
-        - name: Checkout project
-          uses: actions/checkout@v3
-
-        - name: Install and configure PHP
-          uses: shivammathur/setup-php@v2
-          with:
-            coverage: none
-            php-version: 8.1
-
-        - name: Get composer cache directory
-          id: composer-cache-dir
-          run: echo "::set-output name=dir::$(composer config cache-files-dir)"
-
-        - name: Cache dependencies
-          uses: actions/cache@v2
-          id: composer-cache
-          with:
-            path: ${{ steps.composer-cache-dir.outputs.dir }}
-            key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
-            restore-keys: |
-              ${{ runner.os }}-composer-
-
-        - name: Install dependencies
-          run: composer install --no-interaction --prefer-dist
-
-        - name: Check code style
-          run: vendor/bin/ecs
-
-    phpstan:
-      runs-on: ubuntu-latest
-
-      steps:
-        - name: Checkout project
-          uses: actions/checkout@v3
-
-        - name: Install and configure PHP
-          uses: shivammathur/setup-php@v2
-          with:
-            coverage: none
-            php-version: 8.1
-
-        - name: Get composer cache directory
-          id: composer-cache-dir
-          run: echo "::set-output name=dir::$(composer config cache-files-dir)"
-
-        - name: Cache dependencies
-          uses: actions/cache@v2
-          id: composer-cache
-          with:
-            path: ${{ steps.composer-cache-dir.outputs.dir }}
-            key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
-            restore-keys: |
-              ${{ runner.os }}-composer-
-
-        - name: Install dependencies
-          run: composer install --no-interaction --prefer-dist
-
-        - name: Run PHPStan
-          run: vendor/bin/phpstan analyse
-
-    unit-test:
-        name: 'Run unit tests with php ${{ matrix.php-version }} with symfony ${{ matrix.symfony-version}}'
-        runs-on: ubuntu-latest
-
-        strategy:
-            fail-fast: false
-            matrix:
-                include:
-                    - php-version: '8.0'
-                      symfony-version: '5.4.*'
-
-                    - php-version: '8.1'
-                      symfony-version: '5.4.*'
-
-                    - php-version: '8.1'
-                      symfony-version: '6.0.*'
-
-                    - php-version: '8.1'
-                      symfony-version: '6.1.*'
-
-        steps:
-            - name: Checkout project
-              uses: actions/checkout@v3
-
-            - name: Install and configure PHP
-              uses: shivammathur/setup-php@v2
-              with:
-                  coverage: pcov
-                  php-version: ${{ matrix.php-version }}
-
-            - name: Get composer cache directory
-              id: composer-cache-dir
-              run: echo "::set-output name=dir::$(composer config cache-files-dir)"
-
-            - name: Cache dependencies
-              uses: actions/cache@v2
-              id: composer-cache
-              with:
-                  path: ${{ steps.composer-cache-dir.outputs.dir }}
-                  key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
-                  restore-keys: |
-                      ${{ runner.os }}-composer-
-
-            - name: Install dependencies
-              run: |
-                  composer validate --strict
-                  composer require --no-update symfony/serializer:${{ matrix.symfony-version }}
-                  composer install --no-interaction --prefer-dist
-
-            - name: Run tests
-              run: vendor/bin/phpunit --testsuite=unit --coverage-clover=coverage.xml
-
-    functional-test:
-      name: 'Run functional tests'
-      runs-on: ubuntu-latest
-
-      steps:
-        - name: Checkout project
-          uses: actions/checkout@v3
-
-        - name: Install and configure PHP
-          uses: shivammathur/setup-php@v2
-          with:
-            coverage: none
-            php-version: 8.1
-
-        - name: Get composer cache directory
-          id: composer-cache-dir
-          run: echo "::set-output name=dir::$(composer config cache-files-dir)"
-
-        - name: Cache dependencies
-          uses: actions/cache@v2
-          id: composer-cache
-          with:
-            path: ${{ steps.composer-cache-dir.outputs.dir }}
-            key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
-            restore-keys: |
-              ${{ runner.os }}-composer-
-
-        - name: Install dependencies
-          run: composer install --no-interaction --prefer-dist
-
-        - name: Setup OpenSearch
-          uses: ankane/setup-opensearch@v1
-          with:
-            opensearch-version: '1.2'
-
-        - name: Run tests
-          run: vendor/bin/phpunit --testsuite=functional
+  code-style:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v3
+
+      - name: Install and configure PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          coverage: none
+          php-version: 8.1
+
+      - name: Get composer cache directory
+        id: composer-cache-dir
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+      - name: Cache dependencies
+        uses: actions/cache@v3
+        id: composer-cache
+        with:
+          path: ${{ steps.composer-cache-dir.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --no-interaction --prefer-dist
+
+      - name: Check code style
+        run: vendor/bin/ecs
+
+  phpstan:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v3
+
+      - name: Install and configure PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          coverage: none
+          php-version: 8.1
+
+      - name: Get composer cache directory
+        id: composer-cache-dir
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+      - name: Cache dependencies
+        uses: actions/cache@v3
+        id: composer-cache
+        with:
+          path: ${{ steps.composer-cache-dir.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --no-interaction --prefer-dist
+
+      - name: Run PHPStan
+        run: vendor/bin/phpstan analyse
+
+  unit-test:
+    name: 'Run unit tests with php ${{ matrix.php-version }} with symfony ${{ matrix.symfony-version}}'
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - php-version: '8.0'
+            symfony-version: '5.4.*'
+
+          - php-version: '8.1'
+            symfony-version: '5.4.*'
+
+          - php-version: '8.1'
+            symfony-version: '6.0.*'
+
+          - php-version: '8.1'
+            symfony-version: '6.1.*'
+
+          - php-version: '8.1'
+            symfony-version: '6.2.*'
+
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v3
+
+      - name: Install and configure PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          coverage: pcov
+          php-version: ${{ matrix.php-version }}
+
+      - name: Get composer cache directory
+        id: composer-cache-dir
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+      - name: Cache dependencies
+        uses: actions/cache@v3
+        id: composer-cache
+        with:
+          path: ${{ steps.composer-cache-dir.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: |
+          composer validate --strict
+          composer require --no-update symfony/serializer:${{ matrix.symfony-version }}
+          composer install --no-interaction --prefer-dist
+
+      - name: Run tests
+        run: vendor/bin/phpunit --testsuite=unit --coverage-clover=coverage.xml
+
+  functional-test:
+    name: 'Run functional tests with OS ${{ matrix.opensearch-version }}'
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - opensearch-version: '1.3'
+            opensearch-composer-version: '^1'
+          - opensearch-version: '2.4'
+            opensearch-composer-version: '^2'
+
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v3
+
+      - name: Install and configure PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          coverage: none
+          php-version: 8.1
+
+      - name: Get composer cache directory
+        id: composer-cache-dir
+        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+      - name: Cache dependencies
+        uses: actions/cache@v3
+        id: composer-cache
+        with:
+          path: ${{ steps.composer-cache-dir.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: |
+          composer require --no-update opensearch-project/opensearch-php:${{ matrix.opensearch-composer-version }}
+          composer install --no-interaction --prefer-dist
+
+      - name: Setup OpenSearch
+        uses: ankane/setup-opensearch@v1
+        with:
+          opensearch-version: ${{ matrix.opensearch-version }}
+
+      - name: Run tests
+        run: vendor/bin/phpunit --testsuite=functional
diff --git a/README.md b/README.md
index a88488c9..e51daf77 100644
--- a/README.md
+++ b/README.md
@@ -3,9 +3,9 @@
 This is a fork of the [ongr/elasticsearch-dsl](https://github.com/ongr-io/elasticsearchbundle).
 With some basic changes to support wider range of Symfony Versions.
 
-| Version | Supported OpenSearch Version | Supported Symfony Version |
-|---------|------------------------------|---------------------------|
-| `1.x`   | `^1.2`                       | `5.4.*`, `6.0.*`, `6.1.*` |
+| Version | Supported OpenSearch Version | Supported Symfony Version          |
+|---------|------------------------------|------------------------------------|
+| `1.x`   | `^1.2`, `^2.0`               | `5.4.*`, `6.0.*`, `6.1.*`, `6.2.*` |
 
 ## Documentation
 
diff --git a/composer.json b/composer.json
index 80022959..0f537626 100644
--- a/composer.json
+++ b/composer.json
@@ -20,13 +20,13 @@
     ],
     "require": {
         "php": "8.0.* || 8.1.*",
-        "symfony/serializer": "5.4.* || 6.0.* || 6.1.*",
-        "opensearch-project/opensearch-php": "^1.0"
+        "symfony/serializer": "5.4.* || 6.0.* || 6.1.* || 6.2.*",
+        "opensearch-project/opensearch-php": "^1.0 || ^2.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5",
-        "phpstan/phpstan": "^1.8",
-        "phpstan/phpstan-phpunit": "^1.1",
+        "phpstan/phpstan": "1.8.11",
+        "phpstan/phpstan-phpunit": "1.1.3",
         "rector/rector": "^0.14.5",
         "symplify/easy-coding-standard": "^11.1"
     },
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index da9511f2..4b20532d 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -16,13 +16,13 @@
         </report>
     </coverage>
     <testsuites>
-        <testsuite name="Unit">
+        <testsuite name="unit">
             <directory>./tests/Unit/</directory>
         </testsuite>
-        <testsuite name="Functional">
+        <testsuite name="functional">
             <directory>./tests/Functional/</directory>
         </testsuite>
-        <testsuite name="All">
+        <testsuite name="all">
             <directory>./tests/</directory>
         </testsuite>
     </testsuites>
diff --git a/src/Aggregation/Metric/TopHitsAggregation.php b/src/Aggregation/Metric/TopHitsAggregation.php
index 8e3d46a1..ba19951f 100644
--- a/src/Aggregation/Metric/TopHitsAggregation.php
+++ b/src/Aggregation/Metric/TopHitsAggregation.php
@@ -49,9 +49,13 @@ class TopHitsAggregation extends AbstractAggregation
     public function __construct(string $name, ?int $size = null, ?int $from = null, ?BuilderInterface $sort = null)
     {
         parent::__construct($name);
-        $this->setFrom($from);
+
         $this->setSize($size);
-        $this->addSort($sort);
+        $this->setFrom($from);
+
+        if ($sort !== null) {
+            $this->addSort($sort);
+        }
     }
 
     public function getFrom(): ?int
@@ -120,11 +124,14 @@ public function getArray(): array|stdClass
             $sortsOutput = null;
         }
 
-        $output = array_filter([
-            'sort' => $sortsOutput,
-            'size' => $this->getSize(),
-            'from' => $this->getFrom(),
-        ]);
+        $output = array_filter(
+            [
+                'sort' => $sortsOutput,
+                'size' => $this->getSize(),
+                'from' => $this->getFrom(),
+            ],
+            static fn ($value) => $value !== null
+        );
 
         return empty($output) ? new stdClass() : $output;
     }
diff --git a/src/SearchEndpoint/HighlightEndpoint.php b/src/SearchEndpoint/HighlightEndpoint.php
index d7e61b94..697a6fb0 100644
--- a/src/SearchEndpoint/HighlightEndpoint.php
+++ b/src/SearchEndpoint/HighlightEndpoint.php
@@ -50,6 +50,10 @@ public function add(BuilderInterface $builder, ?string $key = null): string
             throw new OverflowException('Only one highlight can be set');
         }
 
+        if (! $key) {
+            $key = bin2hex(random_bytes(30));
+        }
+
         $this->key = $key;
         $this->highlight = $builder;
 
diff --git a/tests/Functional/AbstractOpenSearchTestCase.php b/tests/Functional/AbstractOpenSearchTestCase.php
index e1174599..4982dc4b 100644
--- a/tests/Functional/AbstractOpenSearchTestCase.php
+++ b/tests/Functional/AbstractOpenSearchTestCase.php
@@ -33,23 +33,22 @@ protected function setUp(): void
         $this->client = ClientBuilder::create()->build();
         $this->deleteIndex();
 
-        $this->client->indices()->create(
-            array_filter(
-                [
-                    'index' => self::INDEX_NAME,
-                    'mapping' => $this->getMapping(),
-                ]
-            )
-        );
-
         $bulkBody = [];
-
         foreach ($this->getDataArray() as $type => $documents) {
+            $index = self::INDEX_NAME . '_' . $type;
+            $this->client->indices()->create(
+                array_filter(
+                    [
+                        'index' => $index,
+                        'mapping' => $this->getMapping(),
+                    ]
+                )
+            );
+
             foreach ($documents as $id => $document) {
                 $bulkBody[] = [
                     'index' => [
-                        '_index' => self::INDEX_NAME,
-                        '_type' => $type,
+                        '_index' => $index,
                         '_id' => $id,
                     ],
                 ];
@@ -111,16 +110,15 @@ protected function tearDown(): void
      * Execute search to the opensearch and handle results.
      *
      * @param Search $search Search object.
-     * @param null $type Types to search. Can be several types split by comma.
+     * @param string $type Type to search.
      * @param bool $returnRaw Return raw response from the client.
      * @return array
      */
-    protected function executeSearch(Search $search, $type = null, $returnRaw = false)
+    protected function executeSearch(Search $search, string $type, bool $returnRaw = false)
     {
         $response = $this->client->search(
             array_filter([
-                'index' => self::INDEX_NAME,
-                'type' => $type,
+                'index' => self::INDEX_NAME . '_' . $type,
                 'body' => $search->toArray(),
             ])
         );
@@ -149,7 +147,7 @@ private function deleteIndex()
     {
         try {
             $this->client->indices()->delete([
-                'index' => self::INDEX_NAME,
+                'index' => self::INDEX_NAME . '*',
             ]);
         } catch (Exception) {
             // Do nothing.
diff --git a/tests/Functional/Query/FunctionScoreQueryTest.php b/tests/Functional/Query/FunctionScoreQueryTest.php
index 385ada99..ce03337d 100644
--- a/tests/Functional/Query/FunctionScoreQueryTest.php
+++ b/tests/Functional/Query/FunctionScoreQueryTest.php
@@ -49,7 +49,7 @@ public function testRandomScore()
 
         $search = new Search();
         $search->addQuery($fquery);
-        $results = $this->executeSearch($search);
+        $results = $this->executeSearch($search, 'product');
 
         $this->assertCount(
             is_countable($this->getDataArray()['product']) ? count($this->getDataArray()['product']) : 0,
@@ -76,7 +76,7 @@ public function testScriptScore()
 
         $search = new Search();
         $search->addQuery($fquery);
-        $results = $this->executeSearch($search);
+        $results = $this->executeSearch($search, 'product');
 
         foreach ($results as $document) {
             $this->assertLessThanOrEqual(20, $document['price']);
diff --git a/tests/Functional/Query/MatchAllQueryTest.php b/tests/Functional/Query/MatchAllQueryTest.php
index 0c3e7570..05efd8a8 100644
--- a/tests/Functional/Query/MatchAllQueryTest.php
+++ b/tests/Functional/Query/MatchAllQueryTest.php
@@ -41,7 +41,7 @@ public function testMatchAll()
 
         $search->addQuery($matchAll);
         $q = $search->getQueries();
-        $results = $this->executeSearch($search);
+        $results = $this->executeSearch($search, 'product');
 
         $this->assertEquals($this->getDataArray()['product'], $results);
     }
diff --git a/tests/Unit/Aggregation/Metric/CardinalityAggregationTest.php b/tests/Unit/Aggregation/Metric/CardinalityAggregationTest.php
index f013f76b..d901fad3 100644
--- a/tests/Unit/Aggregation/Metric/CardinalityAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/CardinalityAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use LogicException;
 use OpenSearchDSL\Aggregation\Metric\CardinalityAggregation;
diff --git a/tests/Unit/Aggregation/Metric/GeoBoundsAggregationTest.php b/tests/Unit/Aggregation/Metric/GeoBoundsAggregationTest.php
index 1dac29b3..dcee0c10 100644
--- a/tests/Unit/Aggregation/Metric/GeoBoundsAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/GeoBoundsAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use LogicException;
 use OpenSearchDSL\Aggregation\Metric\GeoBoundsAggregation;
diff --git a/tests/Unit/Aggregation/Metric/GeoCentroidAggregationTest.php b/tests/Unit/Aggregation/Metric/GeoCentroidAggregationTest.php
index 210a2748..e3fd471a 100644
--- a/tests/Unit/Aggregation/Metric/GeoCentroidAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/GeoCentroidAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use LogicException;
 use OpenSearchDSL\Aggregation\Metric\GeoCentroidAggregation;
diff --git a/tests/Unit/Aggregation/Metric/PercentileRanksAggregationTest.php b/tests/Unit/Aggregation/Metric/PercentileRanksAggregationTest.php
index 0c6ab44e..3faffb5b 100644
--- a/tests/Unit/Aggregation/Metric/PercentileRanksAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/PercentileRanksAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use LogicException;
 use OpenSearchDSL\Aggregation\Metric\PercentileRanksAggregation;
diff --git a/tests/Unit/Aggregation/Metric/PercentilesAggregationTest.php b/tests/Unit/Aggregation/Metric/PercentilesAggregationTest.php
index 147a69a2..7b20946e 100644
--- a/tests/Unit/Aggregation/Metric/PercentilesAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/PercentilesAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use LogicException;
 use OpenSearchDSL\Aggregation\Metric\PercentilesAggregation;
diff --git a/tests/Unit/Aggregation/Metric/StatsAggregationTest.php b/tests/Unit/Aggregation/Metric/StatsAggregationTest.php
index 703dd299..8d6eb18f 100644
--- a/tests/Unit/Aggregation/Metric/StatsAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/StatsAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use OpenSearchDSL\Aggregation\Metric\StatsAggregation;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Unit/Aggregation/Metric/TopHitsAggregationTest.php b/tests/Unit/Aggregation/Metric/TopHitsAggregationTest.php
index df818a97..50f3f930 100644
--- a/tests/Unit/Aggregation/Metric/TopHitsAggregationTest.php
+++ b/tests/Unit/Aggregation/Metric/TopHitsAggregationTest.php
@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace OpenSearchDSL\Tests\Unit\Metric\Aggregation;
+namespace OpenSearchDSL\Tests\Unit\Aggregation\Metric;
 
 use OpenSearchDSL\Aggregation\Metric\TopHitsAggregation;
 use OpenSearchDSL\Sort\FieldSort;