Spring Framework 4.3 introduced the `PropertySourceFactory` SPI for use
with `@PropertySource` on `@Configuration` classes; however, prior to
this commit there was no mechanism to support custom properties file
formats in `@TestPropertySource` for integration tests.
This commit introduces support for configuring a custom
`PropertySourceFactory` via a new `factory` attribute in
`@TestPropertySource` in order to support custom file formats such as
JSON, YAML, etc.
For example, if you create a YamlPropertySourceFactory, you can use it
in integration tests as follows.
@SpringJUnitConfig
@TestPropertySource(locations = "/test.yaml", factory = YamlPropertySourceFactory.class)
class MyTestClass { /* ... /* }
If a custom factory is not specified, traditional `*.properties` and
`*.xml` based `java.util.Properties` file formats are supported, which
was the existing behavior.
Closes gh-30981