Why doesn't Gradle include transitive dependencies in compile / runtime classpath? - build

Question

I'm learning how Gradle works, and I can't understand how it resolves a project transitive dependencies.
For now, I have two projects :
projectA : which has a couple of dependencies on external libraries
projectB : which has only one dependency on projectA
No matter how I try, when I build projectB, gradle doesn't include any projectA dependencies (X and Y) in projectB's compile or runtime classpath. I've only managed to make it work by including projectA's dependencies in projectB's build script, which, in my opinion does not make any sense. These dependencies should be automatically attached to projectB. I'm pretty sure I'm missing something but I can't figure out what.
I've read about "lib dependencies", but it seems to apply only to local projects like described here, not on external dependencies.
Here is the build.gradle I use in the root project (the one that contains both projectA and projectB) :
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath 'com.android.tools.build:gradle:0.3'
}
}
subprojects {
apply plugin: 'java'
apply plugin: 'idea'
group = 'com.company'
repositories {
mavenCentral()
add(new org.apache.ivy.plugins.resolver.SshResolver()) {
name = 'customRepo'
addIvyPattern "ssh://.../repository/[organization]/[module]/[revision]/[module].xml"
addArtifactPattern "ssh://.../[organization]/[module]/[revision]/[module](-[classifier]).[ext]"
}
}
sourceSets {
main {
java {
srcDir 'src/'
}
}
}
idea.module { downloadSources = true }
// task that create sources jar
task sourceJar(type: Jar) {
from sourceSets.main.java
classifier 'sources'
}
// Publishing configuration
uploadArchives {
repositories {
add project.repositories.customRepo
}
}
artifacts {
archives(sourceJar) {
name "$name-sources"
type 'source'
builtBy sourceJar
}
}
}
This one concerns projectA only :
version = '1.0'
dependencies {
compile 'com.company:X:1.0'
compile 'com.company:B:1.0'
}
And this is the one used by projectB :
version = '1.0'
dependencies {
compile ('com.company:projectA:1.0') {
transitive = true
}
}
Thank you in advance for any help, and please, apologize me for my bad English.

Answer 1

I know that this specific version of the question has already been solved, but my searching brought me here and I hope I can save some people the hassle of figuring this out.
Bad foo/build.gradle
dependencies {
implementation 'com.example:widget:1.0.0'
}
Good foo/build.gradle
dependencies {
api 'com.example:widget:1.0.0'
}
bar/build.gradle
dependencies {
implementation project(path: ':foo')
}
implementation hides the widget dependency.
api makes the widget dependency transitive.
From https://stackoverflow.com/a/44493379/68086:
From the Gradle documentation:
dependencies {
api 'commons-httpclient:commons-httpclient:3.1'
implementation 'org.apache.commons:commons-lang3:3.5'
}
Dependencies appearing in the api configurations will be
transitively exposed to consumers of the library, and as such will
appear on the compile classpath of consumers.
Dependencies found in the implementation configuration will, on the
other hand, not be exposed to consumers, and therefore not leak into
the consumers' compile classpath. This comes with several benefits:
dependencies do not leak into the compile classpath of consumers anymore, so you will never accidentally depend on a transitive
dependency
faster compilation thanks to reduced classpath size
less recompilations when implementation dependencies change: consumers would not need to be recompiled
cleaner publishing: when used in conjunction with the new maven-publish plugin, Java libraries produce POM files that
distinguish exactly between what is required to compile against the
library and what is required to use the library at runtime (in other
words, don't mix what is needed to compile the library itself and what
is needed to compile against the library).
The compile configuration still exists, but should not be used as it will not offer the guarantees that the api and implementation
configurations provide.

Answer 2

Finally, the problem didn't come from the scripts. I've just cleared gradle's cache, and each project's build folder, to make this work.

Answer 3

Put the following line in projectB's dependencies.
compile project(':projectA')