R2DBC unable to create connection with h2 protocol

Question

I'm trying to leverage H2 for testing and have the following configuration in src/test/resources/application.yaml:

spring:
  r2dbc:
    url: r2dbc:h2:file://testdb

I have an empty test annotated with @SpringBootTest but when I run it I get the following error:

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.r2dbc.pool.ConnectionPool]: Factory method 'connectionFactory' threw exception; nested exception is java.lang.IllegalStateException: Unable to create a ConnectionFactory for 'ConnectionFactoryOptions{options={driver=h2, protocol=file, host=testdb}}'. Available drivers: [ pool, postgresql, h2 ]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651)
    ... 131 common frames omitted
Caused by: java.lang.IllegalStateException: Unable to create a ConnectionFactory for 'ConnectionFactoryOptions{options={driver=h2, protocol=file, host=testdb}}'. Available drivers: [ pool, postgresql, h2 ]
    at io.r2dbc.spi.ConnectionFactories.get(ConnectionFactories.java:145)
    at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryBuilder.build(ConnectionFactoryBuilder.java:125)
    at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations.createConnectionFactory(ConnectionFactoryConfigurations.java:56)
    at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$Pool.connectionFactory(ConnectionFactoryConfigurations.java:68)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 132 common frames omitted

Here are the relevant dependencies from pom.xml:

<dependency>
    <groupId>io.r2dbc</groupId>
    <artifactId>r2dbc-h2</artifactId>
    <version>0.8.4.RELEASE</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.4.200</version>
    <scope>test</scope>
</dependency>

Answer 1

url: r2dbc:h2:file:///./data/h2db/testdb