feat: Support basic java plugin aware

gradle-language-server/src/main/java/com/microsoft/gradle/GradleServices.java

@@ -267,14 +267,15 @@ public CompletableFuture<Either<List<CompletionItem>, CompletionList>> completio
         containingCall = call;
       }
     }
+    boolean javaPluginsIncluded = this.libraryResolver.isJavaPluginsIncluded(this.completionVisitor.getPlugins(uri));
     CompletionHandler handler = new CompletionHandler();
     // check again
     if (containingCall == null && isGradleRoot(uri, params.getPosition())) {
       return CompletableFuture.completedFuture(Either
-          .forLeft(handler.getCompletionItems(null, Paths.get(uri).getFileName().toString(), this.libraryResolver)));
+          .forLeft(handler.getCompletionItems(null, Paths.get(uri).getFileName().toString(), this.libraryResolver, javaPluginsIncluded)));
     }
     return CompletableFuture.completedFuture(Either.forLeft(
-        handler.getCompletionItems(containingCall, Paths.get(uri).getFileName().toString(), this.libraryResolver)));
+        handler.getCompletionItems(containingCall, Paths.get(uri).getFileName().toString(), this.libraryResolver, javaPluginsIncluded)));
   }
 
   private boolean isGradleRoot(URI uri, Position position) {

gradle-language-server/src/main/java/com/microsoft/gradle/compile/CompletionVisitor.java

@@ -28,7 +28,10 @@
 import org.codehaus.groovy.ast.expr.ConstantExpression;
 import org.codehaus.groovy.ast.expr.Expression;
 import org.codehaus.groovy.ast.expr.GStringExpression;
+import org.codehaus.groovy.ast.expr.MapEntryExpression;
 import org.codehaus.groovy.ast.expr.MethodCallExpression;
+import org.codehaus.groovy.ast.expr.NamedArgumentListExpression;
+import org.codehaus.groovy.ast.expr.TupleExpression;
 import org.codehaus.groovy.ast.stmt.BlockStatement;
 import org.codehaus.groovy.ast.stmt.ExpressionStatement;
 import org.codehaus.groovy.ast.stmt.Statement;
@@ -60,6 +63,7 @@ public Range getRange() {
   private Map<URI, Set<MethodCallExpression>> methodCalls = new HashMap<>();
   private Map<URI, List<Statement>> statements = new HashMap<>();
   private Map<URI, List<Expression>> constants = new HashMap<>();
+  private Map<URI, Set<String>> plugins = new HashMap<>();
 
   public List<DependencyItem> getDependencies(URI uri) {
     return this.dependencies.get(uri);
@@ -77,6 +81,10 @@ public List<Expression> getConstants(URI uri) {
     return this.constants.get(uri);
   }
 
+  public Set<String> getPlugins(URI uri) {
+    return this.plugins.get(uri);
+  }
+
   public void visitCompilationUnit(URI uri, GradleCompilationUnit compilationUnit) {
     this.currentUri = uri;
     compilationUnit.iterator().forEachRemaining(unit -> visitSourceUnit(unit));
@@ -89,6 +97,7 @@ public void visitSourceUnit(SourceUnit unit) {
       this.methodCalls.put(this.currentUri, new HashSet<>());
       this.statements.put(this.currentUri, new ArrayList<>());
       this.constants.put(this.currentUri, new ArrayList<>());
+      this.plugins.put(this.currentUri, new HashSet<>());
       visitModule(moduleNode);
     }
   }
@@ -106,6 +115,16 @@ public void visitMethodCallExpression(MethodCallExpression node) {
     this.methodCalls.get(this.currentUri).add(node);
     if (node.getMethodAsString().equals("dependencies")) {
       this.dependencies.get(this.currentUri).addAll(getDependencies(node));
+    } else if (node.getMethodAsString().equals("plugins")) {
+      // match plugins { id: ${id} }
+      List<String> plugins = getPluginFromPlugins(node);
+      this.plugins.get(this.currentUri).addAll(plugins);
+    } else if (node.getMethodAsString().equals("apply")) {
+      // match apply plugins: '${id}'
+      String plugin = getPluginFromApply(node);
+      if (plugin != null) {
+        this.plugins.get(this.currentUri).add(plugin);
+      }
     }
     super.visitMethodCallExpression(node);
   }
@@ -162,6 +181,62 @@ private List<DependencyItem> getDependencies(ExpressionStatement expressionState
     return Collections.emptyList();
   }
 
+  private String getPluginFromApply(MethodCallExpression node) {
+    Expression argument = node.getArguments();
+    if (argument instanceof TupleExpression) {
+      List<Expression> expressions = ((TupleExpression)argument).getExpressions();
+      for (Expression expression : expressions) {
+        if (expression instanceof NamedArgumentListExpression) {
+          List<MapEntryExpression> mapEntryExpressions = ((NamedArgumentListExpression)expression).getMapEntryExpressions();
+          for (MapEntryExpression mapEntryExp: mapEntryExpressions) {
+            Expression keyExpression = mapEntryExp.getKeyExpression();
+            if (keyExpression instanceof ConstantExpression && keyExpression.getText().equals("plugin")) {
+              return mapEntryExp.getValueExpression().getText();
+            }
+          }
+        }
+      }
+    }
+    return null;
+  }
+
+  private List<String> getPluginFromPlugins(MethodCallExpression node) {
+    Expression objectExpression = node.getObjectExpression();
+    if (objectExpression instanceof MethodCallExpression) {
+      return getPluginFromPlugins((MethodCallExpression)objectExpression);
+    }
+    List<String> results = new ArrayList<>();
+    Expression argument = node.getArguments();
+    if (argument instanceof ArgumentListExpression) {
+      List<Expression> expressions = ((ArgumentListExpression)argument).getExpressions();
+      for (Expression expression : expressions) {
+        if (expression instanceof ConstantExpression && node.getMethodAsString().equals("id")) {
+          results.add(expression.getText());
+        } else if (expression instanceof ClosureExpression) {
+          Statement code = ((ClosureExpression)expression).getCode();
+          if (code instanceof BlockStatement) {
+            results.addAll(getPluginFromPlugins((BlockStatement) code));
+          }
+        }
+      }
+    }
+    return results;
+  }
+
+  private List<String> getPluginFromPlugins(BlockStatement code) {
+    List<String> results = new ArrayList<>();
+    List<Statement> statements = code.getStatements();
+    for (Statement statement : statements) {
+      if (statement instanceof ExpressionStatement) {
+        Expression expression = ((ExpressionStatement)statement).getExpression();
+        if (expression instanceof MethodCallExpression) {
+          results.addAll(getPluginFromPlugins((MethodCallExpression) expression));
+        }
+      }
+    }
+    return results;
+  }
+
   @Override
   public void visitConstantExpression(ConstantExpression expression) {
     this.constants.get(currentUri).add(expression);

gradle-language-server/src/main/java/com/microsoft/gradle/handlers/CompletionHandler.java

@@ -32,8 +32,9 @@ public class CompletionHandler {
 
   private static String BUILD_GRADLE = "build.gradle";
   private static String SETTING_GRADLE = "settings.gradle";
+  private static String DEPENDENCYHANDLER_CLASS = "org.gradle.api.artifacts.dsl.DependencyHandler";
 
-  public List<CompletionItem> getCompletionItems(MethodCallExpression containingCall, String fileName, GradleLibraryResolver resolver) {
+  public List<CompletionItem> getCompletionItems(MethodCallExpression containingCall, String fileName, GradleLibraryResolver resolver, boolean javaPluginsIncluded) {
     String delegateClassName = null;
     if (containingCall == null) {
       if (fileName.equals(BUILD_GRADLE)) {
@@ -51,22 +52,22 @@ public List<CompletionItem> getCompletionItems(MethodCallExpression containingCa
     if (delegateClass == null) {
       return Collections.emptyList();
     }
-    return getCompletionItemsFromClass(delegateClass, resolver, new HashSet<>());
+    return getCompletionItemsFromClass(delegateClass, resolver, javaPluginsIncluded, new HashSet<>());
   }
 
-  private List<CompletionItem> getCompletionItemsFromClass(JavaClass javaClass, GradleLibraryResolver resolver, Set<String> resultSet) {
+  private List<CompletionItem> getCompletionItemsFromClass(JavaClass javaClass, GradleLibraryResolver resolver, boolean javaPluginsIncluded, Set<String> resultSet) {
     if (javaClass == null) {
       return Collections.emptyList();
     }
     List<CompletionItem> results = new ArrayList<>();
     for (String superInterface : javaClass.getInterfaceNames()) {
       if (resolver.getGradleLibraries().containsKey(superInterface)) {
-        results.addAll(getCompletionItemsFromClass(resolver.getGradleLibraries().get(superInterface), resolver, resultSet));
+        results.addAll(getCompletionItemsFromClass(resolver.getGradleLibraries().get(superInterface), resolver, javaPluginsIncluded, resultSet));
       }
     }
     String superClass = javaClass.getSuperclassName();
     if (resolver.getGradleLibraries().containsKey(superClass)) {
-      results.addAll(getCompletionItemsFromClass(resolver.getGradleLibraries().get(superClass), resolver, resultSet));
+      results.addAll(getCompletionItemsFromClass(resolver.getGradleLibraries().get(superClass), resolver, javaPluginsIncluded, resultSet));
     }
     List<String> methodNames = new ArrayList<>();
     Method[] methods = javaClass.getMethods();
@@ -128,6 +129,22 @@ private List<CompletionItem> getCompletionItemsFromClass(JavaClass javaClass, Gr
         }
       }
     }
+    if (javaPluginsIncluded && javaClass.getClassName().equals(DEPENDENCYHANDLER_CLASS)) {
+      // for dependency {}, we offer java configurations if there is any applied java plugin
+      for (String plugin : resolver.getJavaConfigurations()) {
+        StringBuilder builder = new StringBuilder();
+        builder.append(plugin);
+        builder.append("(Object... o)");
+        StringBuilder insertBuilder = new StringBuilder();
+        insertBuilder.append(plugin);
+        insertBuilder.append("($0)");
+        CompletionItem item = new CompletionItem(builder.toString());
+        item.setKind(CompletionItemKind.Function);
+        item.setInsertTextFormat(InsertTextFormat.Snippet);
+        item.setInsertText(insertBuilder.toString());
+        results.add(item);
+      }
+    }
     return results;
   }
 }

gradle-language-server/src/main/java/com/microsoft/gradle/resolver/GradleLibraryResolver.java

@@ -16,26 +16,39 @@
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.nio.file.Path;
+import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Set;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import org.apache.bcel.classfile.ClassFormatException;
 import org.apache.bcel.classfile.ClassParser;
+import org.apache.bcel.classfile.Field;
 import org.apache.bcel.classfile.JavaClass;
 
 public class GradleLibraryResolver {
+
+  private static String JAVA_PLUGIN = "org.gradle.api.plugins.JavaPlugin";
+
   private Map<String, JavaClass> gradleLibraries = new HashMap<>();
+  private Set<String> javaConfigurations = new HashSet<>();
+  private Set<String> javaPlugins = new HashSet<>();
   private String gradleHome;
   private String gradleVersion;
   private boolean gradleWrapperEnabled;
   private String gradleUserHome;
   private Path workspacePath;
 
+  public GradleLibraryResolver() {
+    this.javaPlugins.addAll(Arrays.asList("java", "application", "groovy", "java-library", "war"));
+  }
+
   public void setGradleHome(String gradleHome) {
     this.gradleHome = gradleHome;
   }
@@ -60,6 +73,10 @@ public Map<String, JavaClass> getGradleLibraries() {
     return this.gradleLibraries;
   }
 
+  public Set<String> getJavaConfigurations() {
+    return this.javaConfigurations;
+  }
+
   public void resolve() {
     Path gradleUserHomePath = (this.gradleUserHome == null) ? Path.of(System.getProperty("user.home"), ".gradle")
         : Path.of(this.gradleUserHome);
@@ -86,6 +103,7 @@ public void resolve() {
       }
       JarFile pluginLibJar = new JarFile(pluginLibFile);
       getGradleLibraries(pluginLibFile.toPath(), pluginLibJar);
+      resolveJavaConfigurations();
     } catch (Exception e) {
       // Do Nothing
     }
@@ -190,4 +208,33 @@ private void getGradleLibraries(Path jarPath, JarFile jarFile) {
       }
     }
   }
+
+  private void resolveJavaConfigurations() {
+    JavaClass javaPluginClass = this.gradleLibraries.get(GradleLibraryResolver.JAVA_PLUGIN);
+    if (javaPluginClass == null) {
+      return;
+    }
+    for (Field field : javaPluginClass.getFields()) {
+      if (field.getName().endsWith("CONFIGURATION_NAME")) {
+        this.javaConfigurations.add(removeQuotes(field.getConstantValue().toString()));
+      }
+    }
+  }
+
+  private static String removeQuotes(String original) {
+    // for those fields parsed from class files, we get ""values"", so we remove the starting and ending quotes here
+    if (original.length() < 3) {
+      return original;
+    }
+    return original.substring(1, original.length() - 1);
+  }
+
+  public boolean isJavaPluginsIncluded(Set<String> plugins) {
+    for (String plugin : plugins) {
+      if (this.javaPlugins.contains(plugin)) {
+        return true;
+      }
+    }
+    return false;
+  }
 }