Add eclipse support

.github/workflows/testing.yml

@@ -27,7 +27,8 @@ jobs:
     needs: build
     strategy:
       matrix:
-        tests: [ProtobufJavaPluginTest, ProtobufKotlinDslCopySpecTest, ProtobufKotlinDslPluginTest, ProtobufAndroidPluginTest, ProtobufAndroidPluginKotlinTest, AndroidProjectDetectionTest]
+        tests: [ProtobufJavaPluginTest, ProtobufKotlinDslCopySpecTest, ProtobufKotlinDslPluginTest, ProtobufAndroidPluginTest, ProtobufAndroidPluginKotlinTest, AndroidProjectDetectionTest, IDESupportTest]
+      fail-fast: false
     runs-on: ubuntu-latest
     timeout-minutes: 30
     steps:

src/main/groovy/com/google/protobuf/gradle/ProtobufPlugin.groovy

@@ -482,6 +482,7 @@ class ProtobufPlugin implements Plugin<Project> {
         project.tasks.withType(GenerateProtoTask).each { GenerateProtoTask generateProtoTask ->
           generateProtoTask.getOutputSourceDirectories().each { File outputDir ->
             Utils.addToIdeSources(project, generateProtoTask.isTest, outputDir, true)
+            Utils.addToEclipseSources(project, generateProtoTask.isTest, generateProtoTask.sourceSet.name, outputDir)
           }
         }
       }

src/main/groovy/com/google/protobuf/gradle/Utils.groovy

@@ -33,6 +33,10 @@ import groovy.transform.CompileStatic
 import org.apache.commons.lang.StringUtils
 import org.gradle.api.Project
 import org.gradle.api.tasks.SourceSet
+import org.gradle.plugins.ide.eclipse.model.Classpath
+import org.gradle.plugins.ide.eclipse.model.ClasspathEntry
+import org.gradle.plugins.ide.eclipse.model.EclipseModel
+import org.gradle.plugins.ide.eclipse.model.SourceFolder
 import org.gradle.plugins.ide.idea.GenerateIdeaModule
 import org.gradle.plugins.ide.idea.model.IdeaModel
 import org.gradle.util.GUtil
@@ -129,4 +133,78 @@ class Utils {
       }
     }
   }
+
+  /**
+   * Add the the folder of generated source to Eclipse .classpath file.
+   */
+  static void addToEclipseSources(Project project, boolean isTest, String sourceSetName, File f) {
+    project.plugins.withId("eclipse") {
+      File projectDir = project.getProjectDir()
+
+      EclipseModel model = project.getExtensions().findByType(EclipseModel)
+      model.classpath.file.whenMerged { Classpath cp ->
+        // buildship requires the folder exists on disk, otherwise
+        // it will be ignored when updating classpath file, see:
+        // https://github.com/eclipse/buildship/issues/1196
+        f.mkdirs()
+
+        String relativePath = projectDir.toURI().relativize(f.toURI()).getPath()
+        // remove trailing slash
+        if (relativePath.endsWith("/")) {
+          relativePath = relativePath[0..(relativePath.length() - 2)]
+        }
+        SourceFolder entry = new SourceFolder(relativePath, getOutputPath(cp, sourceSetName))
+        entry.entryAttributes.put("optional", "true")
+        entry.entryAttributes.put("ignore_optional_problems", "true")
+
+        // this attribute is optional, but it could be useful for IDEs to recognize that it is
+        // generated source folder from protobuf, thus providing some support for that.
+        // e.g. Hint user to run generate tasks if the folder is empty or does not exist.
+        entry.entryAttributes.put("protobuf_generated_source", "true")
+
+        // check if output is not null here because test source folder
+        // must have a separate output folder in Eclipse
+        if (entry.output != null && isTest) {
+          entry.entryAttributes.put("test", "true")
+        }
+        cp.entries.add(entry)
+      }
+    }
+  }
+
+  /**
+   * Get the output path according to the source set name, if no valid path can be
+   * found, <code>null</code> will return.
+   */
+  private static String getOutputPath(Classpath classpath, String sourceSetName) {
+    String path = "bin/" + sourceSetName
+    if (isValidOutput(classpath, path)) {
+      return path
+    }
+    // fallback to default output
+    return null
+  }
+
+  /**
+   * Check if the output path is valid or not.
+   * See: org.eclipse.jdt.internal.core.ClasspathEntry#validateClasspath()
+   */
+  private static boolean isValidOutput(Classpath classpath, String path) {
+    Set<String> outputs = []
+    for (ClasspathEntry cpe : classpath.getEntries()) {
+      if (cpe instanceof SourceFolder) {
+        outputs.add(((SourceFolder) cpe).getOutput())
+      }
+    }
+    for (String output : outputs) {
+      if (Objects.equals(output, path)) {
+        continue
+      }
+      // Eclipse does not allow nested output path
+      if (output.startsWith(path) || path.startsWith(output)) {
+        return false
+      }
+    }
+    return true
+  }
 }

src/test/groovy/com/google/protobuf/gradle/IDESupportTest.groovy

@@ -0,0 +1,142 @@
+package com.google.protobuf.gradle
+
+import com.google.common.collect.ImmutableSet
+import groovy.transform.CompileDynamic
+import org.gradle.testkit.runner.BuildResult
+import org.gradle.testkit.runner.GradleRunner
+import org.gradle.testkit.runner.TaskOutcome
+import spock.lang.Specification
+import spock.lang.Unroll
+
+/**
+ * Unit tests to check ide metadata generation
+ */
+@CompileDynamic
+class IDESupportTest extends Specification {
+  // Current supported version is Gradle 5+.
+  private static final List<String> GRADLE_VERSIONS = ["5.6", "6.0", "6.7.1", "7.4.2"]
+
+  @Unroll
+  void "testProject proto and generated output directories should be added to intellij [gradle #gradleVersion]"() {
+    given: "project from testProject"
+    File projectDir = ProtobufPluginTestHelper.projectBuilder('testIdea')
+      .copyDirs('testProjectBase', 'testProject')
+      .build()
+
+    when: "idea is invoked"
+    BuildResult result = GradleRunner.create()
+      .withProjectDir(projectDir)
+      .withArguments('idea')
+      .withPluginClasspath()
+      .withGradleVersion(gradleVersion)
+      .build()
+
+    then: "it succeed"
+    result.task(":idea").outcome == TaskOutcome.SUCCESS
+    Node imlRoot = new XmlParser().parse(projectDir.toPath().resolve("testProject.iml").toFile())
+    Collection rootMgr = imlRoot.component.findAll { it.'@name' == 'NewModuleRootManager' }
+    assert rootMgr.size() == 1
+    assert rootMgr.content.sourceFolder.size() == 1
+
+    Set<String> sourceDir = [] as Set
+    Set<String> testSourceDir = [] as Set
+    Set<String> generatedDirs = [] as Set
+    rootMgr.content.sourceFolder[0].each {
+      if (Boolean.parseBoolean(it.@isTestSource)) {
+        testSourceDir.add(it.@url)
+      } else {
+        sourceDir.add(it.@url)
+      }
+      if (Boolean.parseBoolean(it.@generated)) {
+        generatedDirs.add(it.@url)
+      }
+    }
+
+    Set<String> expectedSourceDir = ImmutableSet.builder()
+      .add('file://$MODULE_DIR$/src/main/java')
+      .add('file://$MODULE_DIR$/src/grpc/proto')
+      .add('file://$MODULE_DIR$/src/main/proto')
+      .add('file://$MODULE_DIR$/build/extracted-include-protos/grpc')
+      .add('file://$MODULE_DIR$/build/extracted-protos/main')
+      .add('file://$MODULE_DIR$/build/extracted-include-protos/main')
+      .add('file://$MODULE_DIR$/build/extracted-protos/grpc')
+      .add('file://$MODULE_DIR$/build/generated/source/proto/grpc/java')
+      .add('file://$MODULE_DIR$/build/generated/source/proto/grpc/grpc_output')
+      .add('file://$MODULE_DIR$/build/generated/source/proto/main/java')
+      .build()
+    Set<String> expectedTestSourceDir = ImmutableSet.builder()
+      .add('file://$MODULE_DIR$/src/test/java')
+      .add('file://$MODULE_DIR$/src/test/proto')
+      .add('file://$MODULE_DIR$/build/extracted-protos/test')
+      .add('file://$MODULE_DIR$/build/extracted-include-protos/test')
+      .add('file://$MODULE_DIR$/build/generated/source/proto/test/java')
+      .build()
+    Set<String> expectedGeneratedDirs = [
+      'file://$MODULE_DIR$/build/extracted-include-protos/grpc',
+      'file://$MODULE_DIR$/build/extracted-protos/main',
+      'file://$MODULE_DIR$/build/extracted-include-protos/main',
+      'file://$MODULE_DIR$/build/extracted-protos/grpc',
+      'file://$MODULE_DIR$/build/generated/source/proto/grpc/java',
+      'file://$MODULE_DIR$/build/generated/source/proto/grpc/grpc_output',
+      'file://$MODULE_DIR$/build/generated/source/proto/main/java',
+      'file://$MODULE_DIR$/build/extracted-protos/test',
+      'file://$MODULE_DIR$/build/extracted-include-protos/test',
+      'file://$MODULE_DIR$/build/generated/source/proto/test/java',
+    ]
+    assert Objects.equals(expectedSourceDir, sourceDir)
+    assert Objects.equals(expectedTestSourceDir, testSourceDir)
+    Objects.equals(expectedGeneratedDirs, generatedDirs)
+
+    where:
+    gradleVersion << GRADLE_VERSIONS
+  }
+
+  @Unroll
+  void "testProject proto and generated output directories should be added to Eclipse [gradle #gradleVersion]"() {
+    given: "project from testProject"
+    File projectDir = ProtobufPluginTestHelper.projectBuilder('testEclipse')
+      .copyDirs('testProjectBase', 'testProject')
+      .build()
+
+    when: "eclipse is invoked"
+    BuildResult result = GradleRunner.create()
+      .withProjectDir(projectDir)
+      .withArguments('eclipse')
+      .withPluginClasspath()
+      .withGradleVersion(gradleVersion)
+      .build()
+
+    then: "it succeed"
+    result.task(":eclipse").outcome == TaskOutcome.SUCCESS
+    Node classpathFile = new XmlParser().parse(projectDir.toPath().resolve(".classpath").toFile())
+    Collection srcEntries = classpathFile.classpathentry.findAll { it.'@kind' == 'src' }
+    assert srcEntries.size() == 6
+
+    Set<String> sourceDir = [] as Set
+    srcEntries.each {
+      String path = it.@path
+      sourceDir.add(path)
+      if (path.startsWith("build/generated/source/proto")) {
+        if (path.contains("test")) {
+          // test source path has one more attribute: ["test"="true"]
+          assert it.attributes.attribute.size() == 4
+        } else {
+          assert it.attributes.attribute.size() == 3
+        }
+      }
+    }
+
+    Set<String> expectedSourceDir = ImmutableSet.builder()
+      .add('src/main/java')
+      .add('src/test/java')
+      .add('build/generated/source/proto/grpc/java')
+      .add('build/generated/source/proto/grpc/grpc_output')
+      .add('build/generated/source/proto/main/java')
+      .add('build/generated/source/proto/test/java')
+      .build()
+    assert Objects.equals(expectedSourceDir, sourceDir)
+
+    where:
+    gradleVersion << GRADLE_VERSIONS
+  }
+}

src/test/groovy/com/google/protobuf/gradle/ProtobufJavaPluginTest.groovy

@@ -1,6 +1,5 @@
 package com.google.protobuf.gradle
 
-import com.google.common.collect.ImmutableSet
 import groovy.transform.CompileDynamic
 import org.gradle.api.Project
 import org.gradle.testfixtures.ProjectBuilder
@@ -339,81 +338,6 @@ class ProtobufJavaPluginTest extends Specification {
     gradleVersion << GRADLE_VERSIONS
   }
 
-  @Unroll
-  void "testProject proto and generated output directories should be added to intellij [gradle #gradleVersion]"() {
-    given: "project from testProject"
-    File projectDir = ProtobufPluginTestHelper.projectBuilder('testIdea')
-        .copyDirs('testProjectBase', 'testProject')
-        .build()
-
-    when: "idea is invoked"
-    BuildResult result = GradleRunner.create()
-      .withProjectDir(projectDir)
-      .withArguments('idea')
-      .withPluginClasspath()
-      .withGradleVersion(gradleVersion)
-      .build()
-
-    then: "it succeed"
-    result.task(":idea").outcome == TaskOutcome.SUCCESS
-    Node imlRoot = new XmlParser().parse(projectDir.toPath().resolve("testProject.iml").toFile())
-    Collection rootMgr = imlRoot.component.findAll { it.'@name' == 'NewModuleRootManager' }
-    assert rootMgr.size() == 1
-    assert rootMgr.content.sourceFolder.size() == 1
-
-    Set<String> sourceDir = [] as Set
-    Set<String> testSourceDir = [] as Set
-    Set<String> generatedDirs = [] as Set
-    rootMgr.content.sourceFolder[0].each {
-      if (Boolean.parseBoolean(it.@isTestSource)) {
-        testSourceDir.add(it.@url)
-      } else {
-        sourceDir.add(it.@url)
-      }
-      if (Boolean.parseBoolean(it.@generated)) {
-        generatedDirs.add(it.@url)
-      }
-    }
-
-    Set<String> expectedSourceDir = ImmutableSet.builder()
-        .add('file://$MODULE_DIR$/src/main/java')
-        .add('file://$MODULE_DIR$/src/grpc/proto')
-        .add('file://$MODULE_DIR$/src/main/proto')
-        .add('file://$MODULE_DIR$/build/extracted-include-protos/grpc')
-        .add('file://$MODULE_DIR$/build/extracted-protos/main')
-        .add('file://$MODULE_DIR$/build/extracted-include-protos/main')
-        .add('file://$MODULE_DIR$/build/extracted-protos/grpc')
-        .add('file://$MODULE_DIR$/build/generated/source/proto/grpc/java')
-        .add('file://$MODULE_DIR$/build/generated/source/proto/grpc/grpc_output')
-        .add('file://$MODULE_DIR$/build/generated/source/proto/main/java')
-        .build()
-    Set<String> expectedTestSourceDir = ImmutableSet.builder()
-        .add('file://$MODULE_DIR$/src/test/java')
-        .add('file://$MODULE_DIR$/src/test/proto')
-        .add('file://$MODULE_DIR$/build/extracted-protos/test')
-        .add('file://$MODULE_DIR$/build/extracted-include-protos/test')
-        .add('file://$MODULE_DIR$/build/generated/source/proto/test/java')
-        .build()
-    Set<String> expectedGeneratedDirs = [
-      'file://$MODULE_DIR$/build/extracted-include-protos/grpc',
-      'file://$MODULE_DIR$/build/extracted-protos/main',
-      'file://$MODULE_DIR$/build/extracted-include-protos/main',
-      'file://$MODULE_DIR$/build/extracted-protos/grpc',
-      'file://$MODULE_DIR$/build/generated/source/proto/grpc/java',
-      'file://$MODULE_DIR$/build/generated/source/proto/grpc/grpc_output',
-      'file://$MODULE_DIR$/build/generated/source/proto/main/java',
-      'file://$MODULE_DIR$/build/extracted-protos/test',
-      'file://$MODULE_DIR$/build/extracted-include-protos/test',
-      'file://$MODULE_DIR$/build/generated/source/proto/test/java',
-    ]
-    assert Objects.equals(expectedSourceDir, sourceDir)
-    assert Objects.equals(expectedTestSourceDir, testSourceDir)
-    Objects.equals(expectedGeneratedDirs, generatedDirs)
-
-    where:
-    gradleVersion << GRADLE_VERSIONS
-  }
-
   @Unroll
   void "test proto generation is not up-to-date on dependency changes [gradle #gradleVersion]"() {
     given: "project from testProject"

testProject/build.gradle

@@ -3,6 +3,7 @@
 plugins {
   id 'java'
   id 'idea'
+  id 'eclipse'
   id 'com.google.protobuf'
 }
 apply from: 'build_base.gradle'