ACP2E-456: Mexican currency symbol (MX$) is not displayed for es_MX locale

Author: Anna Bukatar

app/code/Magento/CurrencySymbol/Model/System/Currencysymbol.php

@@ -174,11 +174,11 @@ public function getCurrencySymbolsData()
 
             if (isset($currentSymbols[$code]) && !empty($currentSymbols[$code])) {
                 $this->_symbolsData[$code]['displaySymbol'] = $currentSymbols[$code];
+                $this->_symbolsData[$code]['inherited'] = false;
             } else {
                 $this->_symbolsData[$code]['displaySymbol'] = $this->_symbolsData[$code]['parentSymbol'];
+                $this->_symbolsData[$code]['inherited'] = true;
             }
-            $this->_symbolsData[$code]['inherited'] =
-                ($this->_symbolsData[$code]['parentSymbol'] == $this->_symbolsData[$code]['displaySymbol']);
         }
 
         return $this->_symbolsData;
@@ -194,7 +194,7 @@ public function setCurrencySymbolsData($symbols = [])
     {
         if (!$this->_storeManager->isSingleStoreMode()) {
             foreach ($this->getCurrencySymbolsData() as $code => $values) {
-                if (isset($symbols[$code]) && ($symbols[$code] == $values['parentSymbol'] || empty($symbols[$code]))) {
+                if (isset($symbols[$code]) && empty($symbols[$code])) {
                     unset($symbols[$code]);
                 }
             }

dev/tests/integration/testsuite/Magento/CurrencySymbol/Model/System/CurrencysymbolTest.php

@@ -20,20 +20,31 @@ class CurrencysymbolTest extends \PHPUnit\Framework\TestCase
      */
     protected $currencySymbolModel;
 
+    /**
+     * @inheirtDoc
+     */
     protected function setUp(): void
     {
         $this->currencySymbolModel = Bootstrap::getObjectManager()->create(
             \Magento\CurrencySymbol\Model\System\Currencysymbol::class
         );
     }
 
+    /**
+     * @inheirtDoc
+     */
     protected function tearDown(): void
     {
         $this->currencySymbolModel = null;
         Bootstrap::getObjectManager()->get(\Magento\Framework\App\Config\ReinitableConfigInterface::class)->reinit();
         Bootstrap::getObjectManager()->create(\Magento\Store\Model\StoreManagerInterface::class)->reinitStores();
     }
 
+    /**
+     * Test that getCurrencySymbolsData method returns valid data
+     *
+     * @return void
+     */
     public function testGetCurrencySymbolsData()
     {
         $currencySymbolsData = $this->currencySymbolModel->getCurrencySymbolsData();
@@ -80,8 +91,37 @@ public function testSetCurrencySymbolsData()
         $this->assertEquals('@', $this->currencySymbolModel->getCurrencySymbol('EUR'), 'Symbol not set correctly.');
     }
 
+    /**
+     * Test that method returns valid data
+     *
+     * @return void
+     */
     public function testGetCurrencySymbolNonExistent()
     {
         $this->assertFalse($this->currencySymbolModel->getCurrencySymbol('AUD'));
     }
+
+    /**
+     * Test that default symbol can be set to use explicitly in the system
+     *
+     * @return void
+     */
+    public function testSetCurrencySymbolLikeParent()
+    {
+        $currencySymbolsData = ['USD' => '$'];
+        $this->currencySymbolModel->setCurrencySymbolsData($currencySymbolsData);
+
+        //Verify if the new symbol is set
+        $this->assertEquals(
+            '$',
+            $this->currencySymbolModel->getCurrencySymbolsData()['USD']['displaySymbol'],
+            'Symbol was not correctly set.'
+        );
+
+        $this->assertEquals(
+            false,
+            $this->currencySymbolModel->getCurrencySymbolsData()['USD']['inherited'],
+            'Symbol\'s inheritance was not correctly set.'
+        );
+    }
 }