Add REGEXP_REPLACE support (including unit test)

tests/WP_SQLite_Translator_Tests.php

@@ -118,6 +118,36 @@ public static function regexpOperators() {
  );
  }
 
+ public function testRegexpReplace() {
+ /* Testing if an actual replacment works correctly */
+ $this->assertQuery(
+ "INSERT INTO _options (option_name, option_value) VALUES ('test-ignore', '1');"
+ );
+ $this->assertQuery(
+ "INSERT INTO _options (option_name, option_value) VALUES ('test-remove', '2');"
+ );
+ $this->assertQuery( "SELECT * FROM _options WHERE REGEXP_REPLACE(option_name, '(-ignore|-remove)', '') = 'test'" );
+ $this->assertCount( 2, $this->engine->get_query_results() );
+
+ /* If one of the required parameters is null, the return value is null, copying the MYSQL/MariaDB behavior */
+ $this->assertQuery( "SELECT REGEXP_REPLACE( null, 'a', 'x') as result" );
+ $results = $this->engine->get_query_results();
+ $this->assertEquals( null, $results[0]->result );
+
+ $this->assertQuery( "SELECT REGEXP_REPLACE( 'abc', null, 'x') as result" );
+ $results = $this->engine->get_query_results();
+ $this->assertEquals( null, $results[0]->result );
+
+ $this->assertQuery( "SELECT REGEXP_REPLACE( 'abc', 'a', null) as result" );
+ $results = $this->engine->get_query_results();
+ $this->assertEquals( null, $results[0]->result );
+
+ /* Providing an empty pattern should produce an error - but we changed that to null to avoid breaking things */
+ $this->assertQuery( "SELECT REGEXP_REPLACE( 'abc', '', 'x') as result" );
+ $results = $this->engine->get_query_results();
+ $this->assertEquals( null, $results[0]->result );
+ }
+
  public function testInsertDateNow() {
  $this->assertQuery(
  "INSERT INTO _dates (option_name, option_value) VALUES ('first', now());"

wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php

@@ -68,6 +68,7 @@ public function __construct( $pdo ) {
  'isnull' => 'isnull',
  'if' => '_if',
  'regexp' => 'regexp',
+ 'regexp_replace' => 'regexp_replace',
  'field' => 'field',
  'log' => 'log',
  'least' => 'least',
@@ -493,6 +494,54 @@ public function regexp( $pattern, $field ) {
  return preg_match( $pattern, $field );
  }
 
+ /**
+ * Method to emulate MySQL REGEXP_REPLACE() function.
+ *
+ * @param string|array $pattern Regular expression to search for (or array of strings).
+ * @param string|array $replacement The string or an array with strings to replace.
+ * @param string|array $field Haystack.
+ *
+ * @return Array if the field parameter is an array, or a string otherwise.
+ */
+ public function regexp_replace( $field, $pattern, $replacement ) {
+ /*
+ * If the original query says REGEXP BINARY
+ * the comparison is byte-by-byte and letter casing now
+ * matters since lower- and upper-case letters have different
+ * byte codes.
+ *
+ * The REGEXP function can't be easily made to accept two
+ * parameters, so we'll have to use a hack to get around this.
+ *
+ * If the first character of the pattern is a null byte, we'll
+ * remove it and make the comparison case-sensitive. This should
+ * be reasonably safe since PHP does not allow null bytes in
+ * regular expressions anyway.
+ */
+
+ /* Return null if one of the required parameter is null */
+ if ( is_null( $field ) || is_null( $pattern ) || is_null( $replacement ) ) {
+ return null;
+ }
+
+ /* Return null if the pattern is empty - this changes MySQL/MariaDB behavior! */
+ if ( empty( $pattern ) ) {
+ return null;
+ }
+
+ if ( "\x00" === $pattern[0] ) {
+ $pattern = substr( $pattern, 1 );
+ $flags = '';
+ } else {
+ // Otherwise, the search is case-insensitive.
+ $flags = 'i';
+ }
+ $pattern = str_replace( '/', '\/', $pattern );
+ $pattern = '/' . $pattern . '/' . $flags;
+
+ return preg_replace( $pattern, $replacement, $field );
+ }
+
  /**
  * Method to emulate MySQL FIELD() function.
  *