Multi-Project (multi-module project)

• While some small projects and monolithic applications may contain a single build file and source tree, it is often more common for a project to have been split into smaller, interdependent modules.
• The word “interdependent” is vital, as you typically want to link the many modules together through a single build.
• Gradle supports this scenario through multi-project builds.
• This is sometimes referred to as a multi-module project.
• A multi-project build consists of one root project and one or more subprojects.

Multi-Project 구조

• The following represents the structure of a multi-project build that contains two subprojects:
  • The settings.gradle.kts file should include all subprojects.
  • Each subproject should have its own build.gradle.kts file.

Multi-Project 표준

The Gradle community has two standards for multi-project build structures:

• Multi-Project Builds using buildSrc
  • where buildSrc is a subproject-like directory at the Gradle project root containing all the build logic.
• Composite Builds
  • a build that includes other builds where build-logic is a build directory at the Gradle project root containing all the build logic.

Multi-Project building and testing

• The build task is typically used to compile, test, and check a single project.
• In multi-project builds, you may often want to do all of these tasks across various projects.

• The buildNeeded and buildDependents tasks can help with this.

• 아래 예시의 구조에서, the :services:person-service project depends on both the :api and :shared projects.
• The :api project also depends on the :shared project.

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.
├── buildSrc
│   ...
├── api
│   ├── src
│   │   └──...
│   └── build.gradle
├── services
│   └── person-service
│       ├── src
│       │   └──...
│       └── build.gradle
├── shared
│   ├── src
│   │   └──...
│   └── build.gradle
└── settings.gradle

• Assuming you are working on a single project, the :api project, you have been making changes but have not built the entire project since performing a clean.
• You want to build any necessary supporting JARs but only perform code quality and unit tests on the parts of the project you have changed.
• The build task does this: ``` $ gradle :api:build

Task :shared:compileJava Task :shared:processResources Task :shared:classes Task :shared:jar Task :api:compileJava Task :api:processResources Task :api:classes Task :api:jar Task :api:assemble Task :api:compileTestJava Task :api:processTestResources Task :api:testClasses Task :api:test Task :api:check Task :api:build

BUILD SUCCESSFUL in 0s

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- If you have just gotten the latest version of the source from your version control system, which included changes in other projects that :api depends on, you might want to build all the projects you depend on AND test them too.
- The `buildNeeded` task builds AND tests all the projects from the project dependencies of the testRuntime configuration:

$ gradle :api:buildNeeded

Task :shared:compileJava Task :shared:processResources Task :shared:classes Task :shared:jar Task :api:compileJava Task :api:processResources Task :api:classes Task :api:jar Task :api:assemble Task :api:compileTestJava Task :api:processTestResources Task :api:testClasses Task :api:test Task :api:check Task :api:build Task :shared:assemble Task :shared:compileTestJava Task :shared:processTestResources Task :shared:testClasses Task :shared:test Task :shared:check Task :shared:build Task :shared:buildNeeded Task :api:buildNeeded

BUILD SUCCESSFUL in 0s

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- You may want to refactor some part of the :api project used in other projects.
- If you make these changes, testing only the :api project is insufficient.
- You must test all projects that depend on the :api project.
- The `buildDependents` task tests ALL the projects that have a project dependency (in the testRuntime configuration) on the specified project:

$ gradle :api:buildDependents

Task :shared:compileJava Task :shared:processResources Task :shared:classes Task :shared:jar Task :api:compileJava Task :api:processResources Task :api:classes Task :api:jar Task :api:assemble Task :api:compileTestJava Task :api:processTestResources Task :api:testClasses Task :api:test Task :api:check Task :api:build Task :services:person-service:compileJava Task :services:person-service:processResources Task :services:person-service:classes Task :services:person-service:jar Task :services:person-service:assemble Task :services:person-service:compileTestJava Task :services:person-service:processTestResources Task :services:person-service:testClasses Task :services:person-service:test Task :services:person-service:check Task :services:person-service:build Task :services:person-service:buildDependents Task :api:buildDependents

BUILD SUCCESSFUL in 0s ```

• Finally, you can build and test everything in all projects.
• Any task you run in the root project folder will cause that same-named task to be run on all the children.
• You can run gradle build to build and test ALL projects.

실전 적용

=> https://techblog.woowahan.com/2637/ => https://www.youtube.com/watch?v=ipDzLJK-7Kc

상품권 플젝 => 상품권몰이랑 나머지 플젝들 하나로 합치기 ??

참고자료

• https://docs.gradle.org/current/userguide/intro_multi_project_builds.html