set exception handler by request format, not always HTML

test/php/Nominatim/DatabaseErrorTest.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Nominatim;
+
+require_once(CONST_BasePath.'/lib/init-website.php');
+require_once(CONST_BasePath.'/lib/DatabaseError.php');
+
+class DatabaseErrorTest extends \PHPUnit\Framework\TestCase
+{
+
+    public function testSqlMessage()
+    {
+        $oSqlStub = $this->getMockBuilder(\DB_Error::class)
+                    ->setMethods(array('getMessage'))
+                    ->getMock();
+
+        $oSqlStub->method('getMessage')
+                ->willReturn('Unknown table.');
+
+        $oErr = new DatabaseError('Sql error', 123, null, $oSqlStub);
+        $this->assertEquals('Sql error', $oErr->getMessage());
+        $this->assertEquals(123, $oErr->getCode());
+        $this->assertEquals('Unknown table.', $oErr->getSqlError());
+
+        // causes a circular reference warning during dump
+        // $this->assertRegExp('/Mock_DB_Error/', $oErr->getSqlDebugDump());
+    }
+
+    public function testSqlObjectDump()
+    {
+        $oErr = new DatabaseError('Sql error', 123, null, array('one' => 'two'));
+        $this->assertRegExp('/two/', $oErr->getSqlDebugDump());
+    }
+
+    public function testChksqlThrows()
+    {
+        $this->expectException(DatabaseError::class);
+        $this->expectExceptionMessage('My custom error message');
+        $this->expectExceptionCode(500);
+
+        $oDB = new \DB_Error;
+        $this->assertEquals(false, chksql($oDB, 'My custom error message'));
+    }
+}