Prefer project modules on dependency resolution per default

README.md

@@ -8,24 +8,25 @@
 
 _Baseline is a family of Gradle plugins for configuring Java projects with sensible defaults for code-style, static analysis, dependency versioning, CircleCI and IntelliJ IDEA/Eclipse integration._
 
-| Plugin                                        | Description            |
-|-----------------------------------------------|------------------------|
-| `com.palantir.baseline-idea`                  | Configures [Intellij IDEA](https://www.jetbrains.com/idea/) with code style and copyright headers
-| `com.palantir.baseline-eclipse`               | Configures [Eclipse](https://www.eclipse.org/downloads/) with code style and copyright headers
-| `com.palantir.baseline-error-prone`           | Static analysis for your Java code using Google's [error-prone](http://errorprone.info/).
-| `com.palantir.baseline-checkstyle`            | Enforces consistent Java formatting using [checkstyle](http://checkstyle.sourceforge.io/)
-| `com.palantir.baseline-format`                | Formats your java files to comply with checkstyle
-| `com.palantir.baseline-scalastyle`            | Enforces formatting using [scalastyle](https://github.com/scalastyle/scalastyle)
-| `com.palantir.baseline-class-uniqueness`      | Analyses your classpath to ensure no fully-qualified class is defined more than once.
-| `com.palantir.baseline-circleci`              | [CircleCI](https://circleci.com/) integration using `$CIRCLE_ARTIFACTS` and `$CIRCLE_TEST_REPORTS` dirs
-| `com.palantir.baseline-config`                | Config files for the above plugins
-| `com.palantir.baseline-reproducibility`       | Sensible defaults to ensure Jar, Tar and Zip tasks can be reproduced
-| `com.palantir.baseline-exact-dependencies`    | Ensures projects explicitly declare all the dependencies they rely on, no more and no less
-| `com.palantir.baseline-encoding`              | Ensures projects use the UTF-8 encoding in compile tasks.
-| `com.palantir.baseline-release-compatibility` | Ensures projects targeting older JREs only compile against classes and methods available in those JREs.
-| `com.palantir.baseline-testing`               | Configures test tasks to dump heap dumps (hprof files) for convenient debugging
-| `com.palantir.baseline-immutables`            | Enables incremental compilation for the [Immutables](http://immutables.github.io/) annotation processor.
-| `com.palantir.baseline-java-versions`         | Configures JDK versions in a consistent way via Gradle Toolchains.
+| Plugin                                         | Description            |
+|------------------------------------------------|------------------------|
+| `com.palantir.baseline-idea`                   | Configures [Intellij IDEA](https://www.jetbrains.com/idea/) with code style and copyright headers
+| `com.palantir.baseline-eclipse`                | Configures [Eclipse](https://www.eclipse.org/downloads/) with code style and copyright headers
+| `com.palantir.baseline-error-prone`            | Static analysis for your Java code using Google's [error-prone](http://errorprone.info/).
+| `com.palantir.baseline-checkstyle`             | Enforces consistent Java formatting using [checkstyle](http://checkstyle.sourceforge.io/)
+| `com.palantir.baseline-format`                 | Formats your java files to comply with checkstyle
+| `com.palantir.baseline-scalastyle`             | Enforces formatting using [scalastyle](https://github.com/scalastyle/scalastyle)
+| `com.palantir.baseline-class-uniqueness`       | Analyses your classpath to ensure no fully-qualified class is defined more than once.
+| `com.palantir.baseline-circleci`               | [CircleCI](https://circleci.com/) integration using `$CIRCLE_ARTIFACTS` and `$CIRCLE_TEST_REPORTS` dirs
+| `com.palantir.baseline-config`                 | Config files for the above plugins
+| `com.palantir.baseline-reproducibility`        | Sensible defaults to ensure Jar, Tar and Zip tasks can be reproduced
+| `com.palantir.baseline-exact-dependencies`     | Ensures projects explicitly declare all the dependencies they rely on, no more and no less
+| `com.palantir.baseline-encoding`               | Ensures projects use the UTF-8 encoding in compile tasks.
+| `com.palantir.baseline-release-compatibility`  | Ensures projects targeting older JREs only compile against classes and methods available in those JREs.
+| `com.palantir.baseline-testing`                | Configures test tasks to dump heap dumps (hprof files) for convenient debugging
+| `com.palantir.baseline-immutables`             | Enables incremental compilation for the [Immutables](http://immutables.github.io/) annotation processor.
+| `com.palantir.baseline-java-versions`          | Configures JDK versions in a consistent way via Gradle Toolchains.
+| `com.palantir.baseline-prefer-project-modules` | Configures Gradle to prefer project modules over external modules on dependency resolution per default.
 
 See also the [Baseline Java Style Guide and Best Practices](./docs).
 

changelog/@unreleased/pr-2056.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Prefer project modules on dependency resolution per default
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/2056

gradle-baseline-java/build.gradle

@@ -90,6 +90,10 @@ gradlePlugin {
             id = 'com.palantir.baseline-enable-preview-flag'
             implementationClass = 'com.palantir.baseline.plugins.BaselineEnablePreviewFlag'
         }
+        baselinePreferProjectModules {
+            id = 'com.palantir.baseline-prefer-project-modules'
+            implementationClass = 'com.palantir.baseline.plugins.BaselinePreferProjectModules'
+        }
     }
 }
 
@@ -130,6 +134,9 @@ pluginBundle {
         baselineEnablePreviewFlag {
             displayName = 'Palantir Baseline --enable-preview Flag Plugin'
         }
+        baselinePreferProjectModules {
+            displayName = 'Palantir Baseline Prefer Project Modules Plugin'
+        }
     }
 }
 

gradle-baseline-java/src/main/groovy/com/palantir/baseline/plugins/Baseline.java

@@ -61,6 +61,7 @@ public void apply(Project project) {
             proj.getPluginManager().apply(BaselineJavaParameters.class);
             proj.getPluginManager().apply(BaselineImmutables.class);
             proj.getPluginManager().apply(BaselineModuleJvmArgs.class);
+            proj.getPluginManager().apply(BaselinePreferProjectModules.class);
         });
     }
 }

gradle-baseline-java/src/main/groovy/com/palantir/baseline/plugins/BaselinePreferProjectModules.java

@@ -0,0 +1,33 @@
+/*
+ * (c) Copyright 2022 Palantir Technologies Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.palantir.baseline.plugins;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+import org.gradle.api.artifacts.ResolutionStrategy;
+
+/**
+ * Prefer project modules that are part of this build over external modules on dependency resolution.
+ */
+public final class BaselinePreferProjectModules implements Plugin<Project> {
+    @Override
+    public void apply(Project project) {
+        project.getConfigurations()
+                .configureEach(
+                        configuration -> configuration.resolutionStrategy(ResolutionStrategy::preferProjectModules));
+    }
+}