Engine: Add setVersion() with strict validation

Engine accepts only versions 7 and above (covering ES 7.x, 8.x, and
OpenSearch 1.x/2.x/3.x via the typeless API). Anything below 7
raises with a clear message pointing at the bundled engine for ES 5
users.

🤖 Generated by [robots](https://vyos.io)

3 files changed, 61 insertions, 0 deletions

diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 298810e..d365d58 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -10,12 +10,14 @@ phutil_register_library_map(array(
   '__library_version__' => 2,
   'class' => array(
     'VyOSElasticModernFulltextStorageEngine' => 'engine/VyOSElasticModernFulltextStorageEngine.php',
+    'VyOSElasticModernFulltextStorageEngineTestCase' => '__tests__/VyOSElasticModernFulltextStorageEngineTestCase.php',
     'VyOSElasticModernHost' => 'host/VyOSElasticModernHost.php',
     'VyOSElasticModernHostTestCase' => '__tests__/VyOSElasticModernHostTestCase.php',
   ),
   'function' => array(),
   'xmap' => array(
     'VyOSElasticModernFulltextStorageEngine' => 'PhabricatorFulltextStorageEngine',
+    'VyOSElasticModernFulltextStorageEngineTestCase' => 'PhutilTestCase',
     'VyOSElasticModernHost' => 'PhabricatorSearchHost',
     'VyOSElasticModernHostTestCase' => 'PhutilTestCase',
   ),
diff --git a/src/__tests__/VyOSElasticModernFulltextStorageEngineTestCase.php b/src/__tests__/VyOSElasticModernFulltextStorageEngineTestCase.php
new file mode 100644
index 0000000..7a41ca1
--- /dev/null
+++ b/src/__tests__/VyOSElasticModernFulltextStorageEngineTestCase.php
@@ -0,0 +1,38 @@
+<?php
+
+final class VyOSElasticModernFulltextStorageEngineTestCase
+  extends PhutilTestCase {
+
+  public function testSetVersionAcceptsSevenAndAbove() {
+    foreach (array(7, 8, 9, 100) as $v) {
+      $engine = new VyOSElasticModernFulltextStorageEngine();
+      $caught = null;
+      try {
+        $engine->setVersion($v);
+      } catch (Exception $e) {
+        $caught = $e;
+      }
+      $this->assertEqual(
+        null,
+        $caught,
+        pht('Expected no exception for version=%d.', $v));
+      $this->assertEqual($v, $engine->getVersion());
+    }
+  }
+
+  public function testSetVersionRejectsBelowSeven() {
+    foreach (array(0, 1, 2, 5, 6) as $v) {
+      $engine = new VyOSElasticModernFulltextStorageEngine();
+      $caught = null;
+      try {
+        $engine->setVersion($v);
+      } catch (Exception $e) {
+        $caught = $e;
+      }
+      $this->assertTrue(
+        $caught !== null,
+        pht('Expected an exception for version=%d.', $v));
+    }
+  }
+
+}
diff --git a/src/engine/VyOSElasticModernFulltextStorageEngine.php b/src/engine/VyOSElasticModernFulltextStorageEngine.php
index f11eeab..60683b1 100644
--- a/src/engine/VyOSElasticModernFulltextStorageEngine.php
+++ b/src/engine/VyOSElasticModernFulltextStorageEngine.php
@@ -7,6 +7,27 @@
 abstract class VyOSElasticModernFulltextStorageEngine
   extends PhabricatorFulltextStorageEngine {
 
+  private $version;
+
+  public function setVersion($version) {
+    $version = (int)$version;
+    if ($version < 7) {
+      throw new Exception(
+        pht(
+          'Unsupported Elasticsearch version "%d" for the '.
+          '"elasticsearch-modern" engine. This engine supports version 7 '.
+          'and above (Elasticsearch 7.x, 8.x, or OpenSearch 1.x/2.x/3.x). '.
+          'For ES 5.x, use the bundled "elasticsearch" engine instead.',
+          $version));
+    }
+    $this->version = $version;
+    return $this;
+  }
+
+  public function getVersion() {
+    return $this->version;
+  }
+
   public function getEngineIdentifier() {
     return 'elasticsearch-modern';
   }