1 files changed, 72 insertions, 0 deletions

diff --git a/buildSrc/src/main/java/tools/refinery/gradle/utils/EclipseUtils.java b/buildSrc/src/main/java/tools/refinery/gradle/utils/EclipseUtils.java
new file mode 100644
index 00000000..1e33a95d
--- /dev/null
+++ b/buildSrc/src/main/java/tools/refinery/gradle/utils/EclipseUtils.java
@@ -0,0 +1,72 @@
+package tools.refinery.gradle.utils;
+
+import groovy.lang.Closure;
+import org.gradle.api.Action;
+import org.gradle.plugins.ide.api.XmlFileContentMerger;
+import org.gradle.plugins.ide.eclipse.model.AbstractClasspathEntry;
+import org.gradle.plugins.ide.eclipse.model.Classpath;
+import org.gradle.plugins.ide.eclipse.model.EclipseModel;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Consumer;
+
+public final class EclipseUtils {
+        private static final String GRADLE_USED_BY_SCOPE_ATTRIBUTE = "gradle_used_by_scope";
+        private static final String GRADLE_USED_BY_SCOPE_SEPARATOR = ",";
+
+        private EclipseUtils() {
+                throw new IllegalStateException("This is a static utility class and should not be instantiated directly");
+        }
+
+        public static void patchClasspathEntries(EclipseModel eclipseModel, Consumer<AbstractClasspathEntry> consumer) {
+                whenClasspathFileMerged(eclipseModel.getClasspath().getFile(),
+                                classpath -> patchClasspathEntries(classpath, consumer));
+        }
+
+        public static void patchClasspathEntries(Classpath eclipseClasspath, Consumer<AbstractClasspathEntry> consumer) {
+                for (var entry : eclipseClasspath.getEntries()) {
+                        if (entry instanceof AbstractClasspathEntry abstractClasspathEntry) {
+                                consumer.accept(abstractClasspathEntry);
+                        }
+                }
+        }
+
+        /**
+         * Avoids ambiguous call to ({@link XmlFileContentMerger#whenMerged(Closure)} versus
+         * {@link XmlFileContentMerger#whenMerged(Action)}) in Kotlin build scripts.
+         * <p>
+         * The {@code Closure} variant will use the build script itself as {@code this}, and Kotlin will consider any
+         * type ascription as a cast of {@code this} (instead of the argument of the {@code Action<?>}). This results in
+         * a mysterious {@link ClassCastException}, since the class generated from the build script doesn't extend from
+         * {@link Classpath}. Using this helper method selects the correct call and applies the cast properly.
+         *
+         * @param file     The Eclipse classpath file.
+         * @param consumer The lambda to run on when the classpath file is merged.
+         */
+        public static void whenClasspathFileMerged(XmlFileContentMerger file, Consumer<Classpath> consumer) {
+                file.whenMerged(untypedClasspath -> {
+                        var classpath = (Classpath) untypedClasspath;
+                        consumer.accept(classpath);
+                });
+        }
+
+        public static void patchGradleUsedByScope(AbstractClasspathEntry entry, Consumer<Set<String>> consumer) {
+                var entryAttributes = entry.getEntryAttributes();
+                var usedByValue = entryAttributes.get(GRADLE_USED_BY_SCOPE_ATTRIBUTE);
+                Set<String> usedBySet;
+                if (usedByValue instanceof String usedByString) {
+                        usedBySet = new LinkedHashSet<>(List.of(usedByString.split(GRADLE_USED_BY_SCOPE_SEPARATOR)));
+                } else {
+                        usedBySet = new LinkedHashSet<>();
+                }
+                consumer.accept(usedBySet);
+                if (usedBySet.isEmpty()) {
+                        entryAttributes.remove(GRADLE_USED_BY_SCOPE_ATTRIBUTE);
+                } else {
+                        var newUsedByString = String.join(GRADLE_USED_BY_SCOPE_SEPARATOR, usedBySet);
+                        entryAttributes.put(GRADLE_USED_BY_SCOPE_ATTRIBUTE, newUsedByString);
+                }
+        }
+}