[BUG] Gradle plugin: incremental build does not work if outputDir is not in $buildDir

[alafanechere]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When I use the GenerateTask and want to target an outputDir which path is not in the $buildDir the client I'm generating is generated on each build and I don't benefit from incremental builds (UP-TO-DATE flag on task).
I'm wondering if this is something related to Gradle our this plugin specifically and if there's an existing workaround.

If I use the $buildDir in the outputDir path the incremental build works, and my client get generated only upon spec updates.

openapi-generator version

5.3.1

Steps to reproduce

No incremental builds with the following build.gradle

import org.openapitools.generator.gradle.plugin.tasks.GenerateTask

plugins {
    id "org.openapi.generator" version "5.3.1"
    id 'airbyte-python'
    id 'airbyte-docker'
}

airbytePython {
    moduleDirectory 'octavia_cli'
}


task generateApiClient(type: GenerateTask) {
    inputSpec =  "$rootDir.absolutePath/airbyte-api/src/main/openapi/config.yaml"
    outputDir = "$projectDir/airbyte_api_client"

    generatorName = "python"
    packageName = "airbyte_api_client"
}

Works as expected when using $buildDir in the outputDir path:

import org.openapitools.generator.gradle.plugin.tasks.GenerateTask

plugins {
    id "org.openapi.generator" version "5.3.1"
    id 'airbyte-python'
    id 'airbyte-docker'
}

airbytePython {
    moduleDirectory 'octavia_cli'
}

task generateApiClient(type: GenerateTask) {
inputSpec = "$rootDir.absolutePath/airbyte-api/src/main/openapi/config.yaml"
outputDir = "$buildDir/airbyte_api_client"

generatorName = "python"
packageName = "airbyte_api_client"

}

Related issues/PRs

@HenningWaack PR's #6716 introduced support for incremental build.

[nbrugger-tgm]

Hi I dug a bit deeper as i am experiencing the same issue but in my case it was my own fault.

To investigate the bug please run you gradle command with --info it will show you why the task is re-run.

If you get an output message such as "From property outputDir file "xyz" was removed" you can use the following code to find whats going wrong

Set<File> bev;
tasks.openApiGenerate.doFirst {
    println "Before : " + it.outputs.files.asFileTree.files.size()
    bev = it.outputs.files.asFileTree.files
}
tasks.openApiGenerate.doLast { it ->
    println "After : " + it.outputs.files.asFileTree.files.size()
    var newOut = new HashSet<>(it.outputs.files.asFileTree.files);
    newOut.removeAll(bev);
    println "Diff (ADDED) : " + newOut
    bev.removeAll(it.outputs.files.asFileTree.files)
    println "Diff (REMOVED) : " + bev
}

This just compares the diff between the output dir before and after the task

[gibbonsite]

Hi, I faced the same issue some time ago -- when I introduce dependency on the task GenerateTask, it consistently is marked as out of date, but no file has changed.

I digged into the problem.

I use version 6.6.0 of org.openapi.generator gradle plugin.
When I decompiled class GenerateTask.class in my IDE I noticed there wasn't annotation @OutputDirectory placed on outputDir field. But it's supposed to be there, see code.

I also checked similar case with inputSpec field -- there wasn't @InputFile annotation on this field in decompiled version of the class.

Why lack of @OutputDirectory is important? Without them, gradle always marks task as out of date.

Please, consider my findings above and fix the problem.

[HenningWaack]

Hi, I could not reproduce the issue using the latest version of writing and using the sample project modules/openapi-generator-gradle-plugin/samples/local-spec. Please try again with latest version of generator and up-to-date version of Gradle and Java.