Using springdoc-openapi as BOM uses Gradle project verson rather than BOM version

[mjustin]

Describe the bug

I don't see it in the project documentation, but from #1099 & #1256, it looks like springdoc-openapi is designed to be used as a BOM, enforcing the dependency versions in the project to match the version of the BOM.

When I use this project as a BOM with Gradle using the Spring dependency management plugin, it uses the version of my Gradle project as the SpringDoc versions, rather than the version of the BOM. For instance, if I have my Gradle project at version 0.0.1, use org.springdoc:springdoc-openapi:1.6.1 as a BOM, and import org.springdoc:springdoc-openapi-ui, the version of springdoc-openapi-ui will be 0.0.1, not 1.6.1.

To Reproduce

build.gradle

plugins {
    id 'org.springframework.boot' version '2.6.1'
    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
    id 'java'
}

group = 'com.example'
version = '0.0.1'
sourceCompatibility = '11'

repositories {
    mavenCentral()
}

dependencyManagement {
    imports {
        mavenBom 'org.springdoc:springdoc-openapi:1.6.1'
        mavenBom 'org.springframework.boot:spring-boot-dependencies:2.6.1'
    }
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter'
    implementation 'org.springdoc:springdoc-openapi-ui'
}

Execute

$ gradle compileJava

> Task :compileJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Could not resolve all files for configuration ':compileClasspath'.
   > Could not find org.springdoc:springdoc-openapi-ui:0.0.1.
     Required by:
         project :

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
1 actionable task: 1 executed

Expected behavior

The expected behavior is that the version used for the springdoc-openapi BOM be used for the org.springdoc dependencies.

[bnasslahsen]

@mjustin,

Review your syntax before logging bugs.

dependencyManagement {
	imports {
		mavenBom('org.springdoc:springdoc-openapi:1.6.2') {
			bomProperty 'version', '1.6.2'
		}
	}
}

[mjustin]

@bnasslahsen

Of all the BOM projects I've used in Gradle projects using Spring Boot (at least four, if not more), this is the only one I've ever had that didn't just work right out of the box without setting a bomProperty. The syntax I've specified is exactly what I typically use, and is the syntax used in the first example in the Dependency Management Plugin documentation. So I certainly wouldn't categorize this as a syntax error.

I do see in the documentation also covers bomProperty.

That being said, it's highly surprising that springdoc-openapi:1.6.2 requires setting the version properly in order to be used. It looks like this mechanism is mostly intended to override a managed version (i.e. there's a standard sensible default that you want to use something different for). I would expect that springdoc-openapi:1.6.2 use 1.6.2 as the version by default. Using the Gradle project's version would virtually never be appropriate, unless that Gradle project happened to be part of springdoc-openapi.

So with that all in mind, and knowing that the version property needs to be set in order to be used, I guess I'd want a bug or feature request that the version be defaulted to match the version of the BOM, rather than the Gradle project version of whatever project happens to be importing the BOM.

[bnasslahsen]

@mjustin,

There no such enchantement plans.
If you feel there is any thing to do there, feel free to submit a PR.

[bnasslahsen]

Additionnally, we dont see any added value for a documentation update.
But if you want documentation update. Submit your PR to this repo.

[mjustin]

@bnasslahsen OK, thanks. If nothing else, it sounds like my inference was correct that this usage as a BOM in consuming projects is in fact intended and supported.

[bnasslahsen]

@mjustin,

I have enhanced the BOM support so that we get rid of the bomProperty line for next releases.
You can already validate it using the latest SNAPSHOT.

[mjustin]

I can confirm that the updated BOM works as desired in my Gradle project where I found this issue. Thanks for the quick fix!