Remove the "string" return type constraint from "filter" function

The filter function can actually return any data type. Because a) the
signature for the base class doesn't include a return type constraint,
and b) the legacy behavior for text filters is to return any argument
that is not a string as-is (thus, returning the same type as the
original value).

Add some additional test cases to make sure we don't re-introduce the
same problem in the future (assuming the base class function signature
doesn't change, of course).

[Fixes: #45]

CHANGELOG.md

@@ -0,0 +1,44 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+- This CHANGELOG.
+
+### Fixed
+- [#45] Exception: Return value must be of type string, null returned
+
+## [2.0.0] - 2022-12-17
+
+### Added
+- Early checks for "text" that cannot be filtered or is not worth filtering (e.g., non-strings, or empty strings).
+- [#35] Addded GitHub Actions and information in README.md, contributed by Luca Bösch.
+
+### Changed
+- [#32] **[BREAKING CHANGE]** Updated the unit test machinery to be compatible with Moodle 3.11 and later. The new machinery is incompatible with Moodle 3.10 and later, making this a breaking change.
+
+### Fixed
+- Fixed some Moodle Code Checker and Documentation Checker warnings.
+
+### Security
+- [#39] MDL-77525 apply multilang2 before text formatting and cleaning
+
+[UNRELEASED]: https://github.com/iarenaza/moodle-filter_multilang2/compare/2.0.0...HEAD
+[2.0.0]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.1.2...2.0.0
+[1.1.2]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.1.1...1.1.2
+[1.1.1]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.0.1...1.1.1
+[1.0.5]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.0.4...1.0.5
+[1.0.4]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.0.3...1.0.4
+[1.0.3]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.0.2...1.0.3
+[1.0.2]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.0.1...1.0.2
+[1.0.1]: https://github.com/iarenaza/moodle-filter_multilang2/compare/1.0...1.0.1
+[1.0]: https://github.com/iarenaza/moodle-filter_multilang2/releases/tag/1.0
+[#45]: https://github.com/iarenaza/moodle-filter_multilang2/pull/45
+[#39]: https://github.com/iarenaza/moodle-filter_multilang2/pull/39
+[#35]: https://github.com/iarenaza/moodle-filter_multilang2/issues/35
+[#32]: https://github.com/iarenaza/moodle-filter_multilang2/issues/32

filter.php

@@ -133,7 +133,7 @@ public function filter_stage_string(string $text, array $options): string {
      * @param array $options The filter options.
      * @return string The filtered text for this multilang block.
      */
-    public function filter($text, array $options = array()): string {
+    public function filter($text, array $options = array()) {
 
         if (!is_string($text) || empty($text)) {
             // Non-string data can not be filtered anyway.

tests/actual_test_cases.php

@@ -256,6 +256,20 @@ function multilang2_actual_test_cases(): array {
             '{mlang ,es}Bad filter syntax{mlang}',
             'es',
         ],
+        [
+            null,
+            null,
+            'es',
+        ],
+        [
+            123,
+            123,
+            'es',
+        ],
+        [
+            123.0,
+            123.0,
+            'es',
+        ],
     ];
 }
-

version.php

@@ -25,7 +25,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2022120900;          // The current plugin version (Date: YYYYMMDDXX).
+$plugin->version   = 2024013100;          // The current plugin version (Date: YYYYMMDDXX).
 $plugin->requires  = 2021051700;          // Requires this Moodle version.
 $plugin->component = 'filter_multilang2'; // Full name of the plugin (used for diagnostics).
 $plugin->release   = '2.0.0';