MDL-73278 phpunit: Add missing payment subsystem and fix dataprovider

While testing the changed unit tests one by one, the
payment/tests/helper_test.php was failing because of a mismatch
between the dataProvider data and the param type.

That made me think why that error was not popping in complete runs
and the answer is that the new (3.10) subsystem is not in the
phpunit.xml.dist file.

Hence, adding it and fixing the dataProvider mismatch.

Finally, it has been detected that some old ICU versions (< 62)
have an incorrect behaviour, not adding the required non-breaking
white-space between the currency abbreviation and the value. So
we are skipping some payment tests if that's found.

payment/tests/helper_test.php

@@ -169,7 +169,7 @@ class helper_test extends advanced_testcase {
      * @param float $surcharge
      * @param string $expected
      */
-    public function test_get_rounded_cost(float $amount, string $currency, float $surcharge, string $expected) {
+    public function test_get_rounded_cost(float $amount, string $currency, float $surcharge, float $expected) {
         $this->assertEquals($expected, helper::get_rounded_cost($amount, $currency, $surcharge));
     }
 
@@ -183,6 +183,20 @@ class helper_test extends advanced_testcase {
      * @param string $expected
      */
     public function test_get_cost_as_string(float $amount, string $currency, float $surcharge, string $expected) {
+        // Some old ICU versions have a bug, where they don't follow the CLDR and they are
+        // missing the non-breaking-space between the currency abbreviation and the value.
+        // i.e. it returns AUD50 instead of AU\xc2\xa050). See the following issues @ ICU:
+        // - https://unicode-org.atlassian.net/browse/ICU-6560
+        // - https://unicode-org.atlassian.net/browse/ICU-8853
+        // - https://unicode-org.atlassian.net/browse/ICU-8840
+        // It has been detected that versions prior to ICU-61.1 / ICU-62.1 come with this
+        // problem. Noticeably Travis images (as of December 2021) use buggy ICU-60.1.
+        // So, here, we are going to dynamically verify the behaviour and skip the
+        // test when buggy one is found. No need to apply this to code as dar as the real
+        // formatting is not critical for the functionality (just small glitch).
+        if ('IRR5' === (new \NumberFormatter('en-AU', \NumberFormatter::CURRENCY))->formatCurrency(5, 'IRR')) {
+            $this->markTestSkipped('Old ICU libraries behavior (ICU < 62), skipping this tests');
+        }
         $this->assertEquals($expected, helper::get_cost_as_string($amount, $currency, $surcharge));
     }
 }

phpunit.xml.dist

@@ -202,6 +202,9 @@
     <testsuite name="core_contentbank_testsuite">
       <directory suffix="_test.php">contentbank/tests</directory>
     </testsuite>
+    <testsuite name="core_payment_testsuite">
+      <directory suffix="_test.php">payment/tests</directory>
+    </testsuite>
 
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