Use test fixtures instead of sourceSets.test.output

This avoids the (often missing) evaluationDependsOn and fixes using
results from other projects without propagating those through
Configuration. It also reduces the number of useless classes pulled in
by down-stream tests, reducing the probability of rebuilds.

The expectation of fixtures is they help testing down-stream code that
use the classes in main. That applies to all the classes here except for
FakeClock and StaticTestingClassLoader. It would also apply to many
internal classes in grpc-testing, but let's consider cleaning that up
future work.

alts/build.gradle

@@ -9,8 +9,6 @@ plugins {
 
 description = "gRPC: ALTS"
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     api project(':grpc-core')
     implementation project(':grpc-auth'),
@@ -28,7 +26,7 @@ dependencies {
     shadow project(path: ':grpc-netty-shaded', configuration: 'shadow')
 
     testImplementation project(':grpc-testing'),
-            project(':grpc-core').sourceSets.test.output,
+            testFixtures(project(':grpc-core')),
             project(':grpc-testing-proto'),
             libraries.guava,
             libraries.junit,

api/build.gradle

@@ -1,5 +1,6 @@
 plugins {
     id "java-library"
+    id "java-test-fixtures"
     id "maven-publish"
 
     id "me.champeau.jmh"
@@ -8,15 +9,16 @@ plugins {
 
 description = 'gRPC: API'
 
-evaluationDependsOn(project(':grpc-context').path)
-
 dependencies {
     api project(':grpc-context'),
             libraries.jsr305,
             libraries.errorprone.annotations
     implementation libraries.guava
 
-    testImplementation project(':grpc-context').sourceSets.test.output,
+    testFixturesImplementation libraries.guava,
+            libraries.junit,
+            libraries.mockito.core
+    testImplementation testFixtures(project(':grpc-context')),
             project(':grpc-testing'),
             project(':grpc-grpclb')
     testImplementation (libraries.guava.testlib) {
@@ -32,3 +34,6 @@ tasks.named("javadoc").configure {
     // We want io.grpc.Internal, but not io.grpc.Internal*
     exclude 'io/grpc/Internal?*.java'
 }
+
+components.java.withVariantsFromConfiguration(configurations.testFixturesApiElements) { skip() }
+components.java.withVariantsFromConfiguration(configurations.testFixturesRuntimeElements) { skip() }

authz/build.gradle

@@ -19,7 +19,7 @@ dependencies {
 
     testImplementation project(':grpc-testing'),
             project(':grpc-testing-proto'),
-            project(':grpc-core').sourceSets.test.output  // for FakeClock
+            testFixtures(project(':grpc-core'))
     testImplementation (libraries.guava.testlib) {
         exclude group: 'junit', module: 'junit'
     }

binder/build.gradle

@@ -7,22 +7,6 @@ description = 'gRPC BinderChannel'
 
 android {
     namespace 'io.grpc.binder'
-    sourceSets {
-        test {
-            java {
-                srcDirs += "${projectDir}/../core/src/test/java/"
-                setIncludes(["io/grpc/internal/FakeClock.java",
-                             "io/grpc/binder/**"])
-            }
-        }
-        androidTest {
-            java {
-                srcDirs += "${projectDir}/../core/src/test/java/"
-                setIncludes(["io/grpc/internal/AbstractTransportTest.java",
-                             "io/grpc/binder/**"])
-            }
-        }
-    }
     compileSdkVersion 31
     compileOptions {
         sourceCompatibility 1.8
@@ -72,6 +56,7 @@ dependencies {
     }
     testImplementation libraries.truth
     testImplementation project(':grpc-testing')
+    testImplementation testFixtures(project(':grpc-core'))
 
     androidTestAnnotationProcessor libraries.auto.value
     androidTestImplementation project(':grpc-testing')
@@ -88,6 +73,7 @@ dependencies {
     androidTestImplementation (libraries.guava.testlib) {
         exclude group: 'junit', module: 'junit'
     }
+    androidTestImplementation testFixtures(project(':grpc-core'))
 }
 
 import net.ltgt.gradle.errorprone.CheckSeverity

census/build.gradle

@@ -7,17 +7,15 @@ plugins {
 
 description = 'gRPC: Census'
 
-evaluationDependsOn(project(':grpc-api').path)
-
 dependencies {
     api project(':grpc-api')
     implementation libraries.guava,
             libraries.opencensus.api,
             libraries.opencensus.contrib.grpc.metrics
 
-    testImplementation project(':grpc-api').sourceSets.test.output,
-            project(':grpc-context').sourceSets.test.output,
-            project(':grpc-core').sourceSets.test.output,
+    testImplementation testFixtures(project(':grpc-api')),
+            testFixtures(project(':grpc-context')),
+            testFixtures(project(':grpc-core')),
             project(':grpc-testing'),
             libraries.opencensus.impl
 

context/build.gradle

@@ -1,5 +1,6 @@
 plugins {
     id "java"
+    id "java-test-fixtures"
     id "maven-publish"
 
     id "me.champeau.gradle.japicmp"
@@ -13,6 +14,10 @@ sourceCompatibility = 1.7
 targetCompatibility = 1.7
 
 dependencies {
+    testFixturesApi libraries.truth
+    // Explicitly choose the guava version to stay Java 7-compatible.
+    testFixturesImplementation 'com.google.guava:guava:30.1.1-android'
+    testFixturesImplementation libraries.jsr305
     testImplementation libraries.jsr305
     // Explicitly choose the guava version to stay Java 7-compatible. The rest of gRPC can move
     // forward to Java 8-requiring versions. This is also only used for testing, so is unlikely to
@@ -23,3 +28,6 @@ dependencies {
     signature "org.codehaus.mojo.signature:java17:1.0@signature"
     signature "net.sf.androidscents.signature:android-api-level-14:4.0_r4@signature"
 }
+
+components.java.withVariantsFromConfiguration(configurations.testFixturesApiElements) { skip() }
+components.java.withVariantsFromConfiguration(configurations.testFixturesRuntimeElements) { skip() }

core/build.gradle

@@ -6,6 +6,7 @@ buildscript {
 
 plugins {
     id "java-library"
+    id "java-test-fixtures"
     id "maven-publish"
 
     id "me.champeau.gradle.japicmp"
@@ -19,9 +20,6 @@ import com.google.common.primitives.Bytes;
 
 description = 'gRPC: Core'
 
-evaluationDependsOn(project(':grpc-context').path)
-evaluationDependsOn(project(':grpc-api').path)
-
 dependencies {
     api project(':grpc-api')
     implementation libraries.gson,
@@ -30,8 +28,13 @@ dependencies {
             libraries.errorprone.annotations,
             libraries.guava,
             libraries.perfmark.api
-    testImplementation project(':grpc-context').sourceSets.test.output,
-            project(':grpc-api').sourceSets.test.output,
+    testFixturesApi libraries.junit
+    testFixturesImplementation libraries.guava,
+            libraries.mockito.core,
+            libraries.truth,
+            project(':grpc-testing')
+    testImplementation testFixtures(project(':grpc-context')),
+            testFixtures(project(':grpc-api')),
             project(':grpc-testing'),
             project(':grpc-grpclb')
     testImplementation (libraries.guava.testlib) {
@@ -61,6 +64,9 @@ animalsniffer {
     ]
 }
 
+components.java.withVariantsFromConfiguration(configurations.testFixturesApiElements) { skip() }
+components.java.withVariantsFromConfiguration(configurations.testFixturesRuntimeElements) { skip() }
+
 import net.ltgt.gradle.errorprone.CheckSeverity
 
 def replaceBytes(byte[] haystack, byte[] needle, byte[] replacement) {

gcp-observability/build.gradle

@@ -62,7 +62,7 @@ dependencies {
             ('io.opencensus:opencensus-api:0.31.1'),
             ('com.google.guava:guava:31.1-jre')
 
-    testImplementation project(':grpc-context').sourceSets.test.output,
+    testImplementation testFixtures(project(':grpc-context')),
             project(':grpc-testing'),
             project(':grpc-testing-proto')
     testImplementation (libraries.guava.testlib) {

googleapis/build.gradle

@@ -13,7 +13,7 @@ dependencies {
                    project(':grpc-core'),
                    project(path: ':grpc-xds', configuration: 'shadow'),
                    libraries.guava.jre // JRE required by transitive protobuf-java-util
-    testImplementation project(':grpc-core').sourceSets.test.output
+    testImplementation testFixtures(project(':grpc-core'))
 
     signature libraries.signature.java
 }

grpclb/build.gradle

@@ -9,8 +9,6 @@ plugins {
 
 description = "gRPC: GRPCLB LoadBalancer plugin"
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     implementation project(':grpc-core'),
             project(':grpc-protobuf'),
@@ -21,7 +19,7 @@ dependencies {
     runtimeOnly libraries.errorprone.annotations
     compileOnly libraries.javax.annotation
     testImplementation libraries.truth,
-            project(':grpc-core').sourceSets.test.output
+            testFixtures(project(':grpc-core'))
 
     signature libraries.signature.java
 }

interop-testing/build.gradle

@@ -13,10 +13,6 @@ configurations {
     alpnagent
 }
 
-evaluationDependsOn(project(':grpc-core').path)
-evaluationDependsOn(project(':grpc-context').path)
-evaluationDependsOn(project(':grpc-api').path)
-
 dependencies {
     implementation project(path: ':grpc-alts', configuration: 'shadow'),
             project(':grpc-auth'),
@@ -49,9 +45,9 @@ dependencies {
             libraries.netty.tcnative.classes,
             project(':grpc-grpclb'),
             project(':grpc-rls')
-    testImplementation project(':grpc-context').sourceSets.test.output,
-            project(':grpc-api').sourceSets.test.output,
-            project(':grpc-core').sourceSets.test.output,
+    testImplementation testFixtures(project(':grpc-context')),
+            testFixtures(project(':grpc-api')),
+            testFixtures(project(':grpc-core')),
             libraries.mockito.core,
             libraries.okhttp
     alpnagent libraries.jetty.alpn.agent

istio-interop-testing/build.gradle

@@ -13,8 +13,6 @@ configurations {
     alpnagent
 }
 
-evaluationDependsOn(project(':grpc-context').path)
-
 dependencies {
     implementation  project(':grpc-core'),
             project(':grpc-netty'),
@@ -28,9 +26,9 @@ dependencies {
 
     runtimeOnly libraries.netty.tcnative,
             libraries.netty.tcnative.classes
-    testImplementation project(':grpc-context').sourceSets.test.output,
-            project(':grpc-api').sourceSets.test.output,
-            project(':grpc-core').sourceSets.test.output,
+    testImplementation testFixtures(project(':grpc-context')),
+            testFixtures(project(':grpc-api')),
+            testFixtures(project(':grpc-core')),
             libraries.mockito.core,
             libraries.junit,
             libraries.truth

netty/build.gradle

@@ -13,8 +13,6 @@ configurations {
     alpnagent
 }
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     api project(':grpc-core'),
             libraries.netty.codec.http2
@@ -25,8 +23,8 @@ dependencies {
             libraries.netty.unix.common
 
     // Tests depend on base class defined by core module.
-    testImplementation project(':grpc-core').sourceSets.test.output,
-            project(':grpc-api').sourceSets.test.output,
+    testImplementation testFixtures(project(':grpc-core')),
+            testFixtures(project(':grpc-api')),
             project(':grpc-testing'),
             project(':grpc-testing-proto'),
             libraries.conscrypt,

okhttp/build.gradle

@@ -8,8 +8,6 @@ plugins {
 
 description = "gRPC: OkHttp"
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     api project(':grpc-core')
     implementation libraries.okio,
@@ -18,8 +16,8 @@ dependencies {
     // Make okhttp dependencies compile only
     compileOnly libraries.okhttp
     // Tests depend on base class defined by core module.
-    testImplementation project(':grpc-core').sourceSets.test.output,
-            project(':grpc-api').sourceSets.test.output,
+    testImplementation testFixtures(project(':grpc-core')),
+            testFixtures(project(':grpc-api')),
             project(':grpc-testing'),
             project(':grpc-testing-proto'),
             libraries.netty.codec.http2,

rls/build.gradle

@@ -8,8 +8,6 @@ plugins {
 
 description = "gRPC: RouteLookupService Loadbalancing plugin"
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     implementation project(':grpc-core'),
             project(':grpc-protobuf'),
@@ -22,7 +20,7 @@ dependencies {
             project(':grpc-grpclb'),
             project(':grpc-testing'),
             project(':grpc-testing-proto'),
-            project(':grpc-core').sourceSets.test.output  // for FakeClock
+            testFixtures(project(':grpc-core'))
     signature libraries.signature.java
 }
 

services/build.gradle

@@ -16,8 +16,6 @@ tasks.named("compileJava").configure {
     ]
 }
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     api project(':grpc-protobuf'),
             project(':grpc-stub'),
@@ -30,7 +28,7 @@ dependencies {
     compileOnly libraries.javax.annotation
     testImplementation project(':grpc-testing'),
             libraries.netty.transport.epoll, // for DomainSocketAddress
-            project(':grpc-core').sourceSets.test.output  // for FakeClock
+            testFixtures(project(':grpc-core'))
     testCompileOnly libraries.javax.annotation
     signature libraries.signature.java
 }

testing/build.gradle

@@ -8,8 +8,6 @@ plugins {
 
 description = "gRPC: Testing"
 
-evaluationDependsOn(project(':grpc-core').path)
-
 dependencies {
     api project(':grpc-core'),
             project(':grpc-stub'),
@@ -24,7 +22,7 @@ dependencies {
     }
 
     testImplementation project(':grpc-testing-proto'),
-            project(':grpc-core').sourceSets.test.output
+            testFixtures(project(':grpc-core'))
 
     signature libraries.signature.java
     signature libraries.signature.android

xds/build.gradle

@@ -11,8 +11,6 @@ plugins {
 
 description = "gRPC: XDS plugin"
 
-evaluationDependsOn(project(':grpc-core').path)
-
 sourceSets {
     thirdparty {
         java {
@@ -57,7 +55,7 @@ dependencies {
     def nettyDependency = implementation project(':grpc-netty')
 
     testImplementation project(':grpc-rls')
-    testImplementation project(':grpc-core').sourceSets.test.output
+    testImplementation testFixtures(project(':grpc-core'))
 
     annotationProcessor libraries.auto.value
     // At runtime use the epoll included in grpc-netty-shaded