Context Configuration with Test Property Sources

The Spring Framework has first-class support for the notion of an environment with a hierarchy of property sources, and you can configure integration tests with test-specific property sources. In contrast to the @PropertySource annotation used on @Configuration classes, you can declare the @TestPropertySource annotation on a test class to declare resource locations for test properties files or inlined properties. These test property sources are added to the set of PropertySources in the Environment for the ApplicationContext loaded for the annotated integration test.

You can use @TestPropertySource with any implementation of the SmartContextLoader SPI, but @TestPropertySource is not supported with implementations of the older ContextLoader SPI.

Implementations of SmartContextLoader gain access to merged test property source values through the getPropertySourceDescriptors() and getPropertySourceProperties() methods in MergedContextConfiguration.

Declaring Test Property Sources

You can configure test properties files by using the locations or value attribute of @TestPropertySource.

By default, both traditional and XML-based java.util.Properties file formats are supported — for example, "classpath:/com/example/test.properties" or "file:///path/to/file.xml". As of Spring Framework 6.1, you can configure a custom PropertySourceFactory via the factory attribute in @TestPropertySource in order to support a different file format such as JSON, YAML, etc.

Each path is interpreted as a Spring Resource. A plain path (for example, "test.properties") is treated as a classpath resource that is relative to the package in which the test class is defined. A path starting with a slash is treated as an absolute classpath resource (for example: "/org/example/test.xml"). A path that references a URL (for example, a path prefixed with classpath:, file:, or http:) is loaded by using the specified resource protocol.

Property placeholders in paths (such as ${…}) will be resolved against the Environment.

As of Spring Framework 6.1, resource location patterns are also supported — for example, "classpath*:/config/*.properties".

The following example uses a test properties file:

Java
Kotlin

@ContextConfiguration
@TestPropertySource("/test.properties") (1)
class MyIntegrationTests {
	// class body...
}

1	Specifying a properties file with an absolute path.

@ContextConfiguration
@TestPropertySource("/test.properties") (1)
class MyIntegrationTests {
	// class body...
}

1	Specifying a properties file with an absolute path.

You can configure inlined properties in the form of key-value pairs by using the properties attribute of @TestPropertySource, as shown in the next example. All key-value pairs are added to the enclosing Environment as a single test PropertySource with the highest precedence.

The supported syntax for key-value pairs is the same as the syntax defined for entries in a Java properties file:

key=value
key:value
key value

Although properties can be defined using any of the above syntax variants and any number of spaces between the key and the value, it is recommended that you use one syntax variant and consistent spacing within your test suite — for example, consider always using key = value instead of key= value, key=value, etc. Similarly, if you define inlined properties using text blocks you should consistently use text blocks for inlined properties throughout your test suite.

The reason is that the exact strings you provide will be used to determine the key for the context cache. Consequently, to benefit from the context cache you must ensure that you define inlined properties consistently.

The following example sets two inlined properties:

Java
Kotlin

@ContextConfiguration
@TestPropertySource(properties = {"timezone = GMT", "port = 4242"}) (1)
class MyIntegrationTests {
	// class body...
}

1	Setting two properties via an array of strings.

@ContextConfiguration
@TestPropertySource(properties = ["timezone = GMT", "port = 4242"]) (1)
class MyIntegrationTests {
	// class body...
}

1	Setting two properties via an array of strings.

As of Spring Framework 6.1, you can use text blocks to define multiple inlined properties in a single String. The following example sets two inlined properties using a text block:

Java
Kotlin

@ContextConfiguration
@TestPropertySource(properties = """
	timezone = GMT
	port = 4242
	""") (1)
class MyIntegrationTests {
	// class body...
}

1	Setting two properties via a text block.

@ContextConfiguration
@TestPropertySource(properties = ["""
	timezone = GMT
	port = 4242
	"""]) (1)
class MyIntegrationTests {
	// class body...
}

1	Setting two properties via a text block.

As of Spring Framework 5.2, @TestPropertySource can be used as repeatable annotation. That means that you can have multiple declarations of @TestPropertySource on a single test class, with the locations and properties from later @TestPropertySource annotations overriding those from previous @TestPropertySource annotations.

In addition, you may declare multiple composed annotations on a test class that are each meta-annotated with @TestPropertySource, and all of those @TestPropertySource declarations will contribute to your test property sources.

Directly present @TestPropertySource annotations always take precedence over meta-present @TestPropertySource annotations. In other words, locations and properties from a directly present @TestPropertySource annotation will override the locations and properties from a @TestPropertySource annotation used as a meta-annotation.

Default Properties File Detection

If @TestPropertySource is declared as an empty annotation (that is, without explicit values for the locations or properties attributes), an attempt is made to detect a default properties file relative to the class that declared the annotation. For example, if the annotated test class is com.example.MyTest, the corresponding default properties file is classpath:com/example/MyTest.properties. If the default cannot be detected, an IllegalStateException is thrown.

Precedence

Test properties have higher precedence than those defined in the operating system’s environment, Java system properties, or property sources added by the application declaratively by using @PropertySource or programmatically. Thus, test properties can be used to selectively override properties loaded from system and application property sources. Furthermore, inlined properties have higher precedence than properties loaded from resource locations. Note, however, that properties registered via @DynamicPropertySource have higher precedence than those loaded via @TestPropertySource.

In the next example, the timezone and port properties and any properties defined in "/test.properties" override any properties of the same name that are defined in system and application property sources. Furthermore, if the "/test.properties" file defines entries for the timezone and port properties those are overridden by the inlined properties declared by using the properties attribute. The following example shows how to specify properties both in a file and inline:

Java
Kotlin

@ContextConfiguration
@TestPropertySource(
	locations = "/test.properties",
	properties = {"timezone = GMT", "port = 4242"}
)
class MyIntegrationTests {
	// class body...
}

@ContextConfiguration
@TestPropertySource("/test.properties",
		properties = ["timezone = GMT", "port = 4242"]
)
class MyIntegrationTests {
	// class body...
}

Inheriting and Overriding Test Property Sources

@TestPropertySource supports boolean inheritLocations and inheritProperties attributes that denote whether resource locations for properties files and inlined properties declared by superclasses should be inherited. The default value for both flags is true. This means that a test class inherits the locations and inlined properties declared by any superclasses. Specifically, the locations and inlined properties for a test class are appended to the locations and inlined properties declared by superclasses. Thus, subclasses have the option of extending the locations and inlined properties. Note that properties that appear later shadow (that is, override) properties of the same name that appear earlier. In addition, the aforementioned precedence rules apply for inherited test property sources as well.

If the inheritLocations or inheritProperties attribute in @TestPropertySource is set to false, the locations or inlined properties, respectively, for the test class shadow and effectively replace the configuration defined by superclasses.

As of Spring Framework 5.3, test configuration may also be inherited from enclosing classes. See @Nested test class configuration for details.

In the next example, the ApplicationContext for BaseTest is loaded by using only the base.properties file as a test property source. In contrast, the ApplicationContext for ExtendedTest is loaded by using the base.properties and extended.properties files as test property source locations. The following example shows how to define properties in both a subclass and its superclass by using properties files:

Java
Kotlin

@TestPropertySource("base.properties")
@ContextConfiguration
class BaseTest {
	// ...
}

@TestPropertySource("extended.properties")
@ContextConfiguration
class ExtendedTest extends BaseTest {
	// ...
}

@TestPropertySource("base.properties")
@ContextConfiguration
open class BaseTest {
	// ...
}

@TestPropertySource("extended.properties")
@ContextConfiguration
class ExtendedTest : BaseTest() {
	// ...
}

In the next example, the ApplicationContext for BaseTest is loaded by using only the inlined key1 property. In contrast, the ApplicationContext for ExtendedTest is loaded by using the inlined key1 and key2 properties. The following example shows how to define properties in both a subclass and its superclass by using inline properties:

Java
Kotlin

@TestPropertySource(properties = "key1 = value1")
@ContextConfiguration
class BaseTest {
	// ...
}

@TestPropertySource(properties = "key2 = value2")
@ContextConfiguration
class ExtendedTest extends BaseTest {
	// ...
}

@TestPropertySource(properties = ["key1 = value1"])
@ContextConfiguration
open class BaseTest {
	// ...
}

@TestPropertySource(properties = ["key2 = value2"])
@ContextConfiguration
class ExtendedTest : BaseTest() {
	// ...
}