Changeset 51331

Build/Test Tools: Replace assertInternalType() usage in unit tests.

The assertInternalType() and assertNotInternalType() methods are deprecated in PHPUnit 8 and removed in PHPUnit 9.

While WordPress test suite currently only supports PHPUnit up to 7.5.x, this allows us to switch to newer assertions ahead of adding full support for PHPUnit 8+.

These methods introduced in PHPUnit 7.5 should be used as an alternative:

• assertIsArray()
• assertIsBool()
• assertIsFloat()
• assertIsInt()
• assertIsNumeric()
• assertIsObject()
• assertIsResource()
• assertIsString()
• assertIsScalar()
• assertIsCallable()
• assertIsIterable()
• assertIsNotArray()
• assertIsNotBool()
• assertIsNotFloat()
• assertIsNotInt()
• assertIsNotNumeric()
• assertIsNotObject()
• assertIsNotResource()
• assertIsNotString()
• assertIsNotScalar()
• assertIsNotCallable()
• assertIsNotIterable()

As WordPress currently uses PHPUnit 5.7.x to run tests on PHP 5.6, polyfills for these methods are now added to the WP_UnitTestCase class for PHPUnit < 7.5.

Props pbearne, jrf, dd32, SergeyBiryukov.
Fixes #53491. See #46149.