replace onDemand static import with single imports (IDEA-175105)

plugins/IntentionPowerPak/src/com/siyeh/ipp/imports/OnDemandImportPredicate.java

@@ -16,8 +16,8 @@
 package com.siyeh.ipp.imports;
 
 import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiImportStatement;
 import com.intellij.psi.PsiImportStatementBase;
+import com.intellij.psi.PsiImportStaticStatement;
 import com.intellij.psi.PsiJavaFile;
 import com.siyeh.ipp.base.PsiElementPredicate;
 import com.siyeh.ipp.psiutils.ErrorUtil;
@@ -27,14 +27,16 @@ class OnDemandImportPredicate implements PsiElementPredicate {
 
   @Override
   public boolean satisfiedBy(@NotNull PsiElement element) {
-    // doesn't work for import static yet.
-    if (!(element instanceof PsiImportStatement)) {
+    if (!(element instanceof PsiImportStatementBase)) {
       return false;
     }
     PsiImportStatementBase importStatement = (PsiImportStatementBase)element;
     if (!importStatement.isOnDemand() || ErrorUtil.containsError(element)) {
       return false;
     }
+    if (importStatement instanceof PsiImportStaticStatement && ((PsiImportStaticStatement)importStatement).resolveTargetClass() == null) {
+      return false;
+    }
     return importStatement.getContainingFile() instanceof PsiJavaFile;
   }
 }

plugins/IntentionPowerPak/src/com/siyeh/ipp/imports/ReplaceOnDemandImportIntention.java

@@ -17,15 +17,14 @@ package com.siyeh.ipp.imports;
 
 import com.intellij.psi.*;
 import com.intellij.psi.util.ClassUtil;
+import com.intellij.psi.util.ImportsUtil;
 import com.siyeh.ig.psiutils.CommentTracker;
 import com.siyeh.ipp.base.Intention;
 import com.siyeh.ipp.base.PsiElementPredicate;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.Arrays;
-import java.util.Comparator;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
+import java.util.function.Function;
 
 public class ReplaceOnDemandImportIntention extends Intention {
 
@@ -38,9 +37,11 @@ public class ReplaceOnDemandImportIntention extends Intention {
   @Override
   protected void processIntention(@NotNull PsiElement element) {
     final PsiImportStatementBase importStatementBase = (PsiImportStatementBase)element;
+    final PsiJavaFile javaFile = (PsiJavaFile)importStatementBase.getContainingFile();
+    final PsiManager manager = importStatementBase.getManager();
+    final PsiElementFactory factory = JavaPsiFacade.getInstance(manager.getProject()).getElementFactory();
     if (importStatementBase instanceof PsiImportStatement) {
       final PsiImportStatement importStatement = (PsiImportStatement)importStatementBase;
-      final PsiJavaFile javaFile = (PsiJavaFile)importStatement.getContainingFile();
       final PsiClass[] classes = javaFile.getClasses();
       final String qualifiedName = importStatement.getQualifiedName();
       final ClassCollector visitor = new ClassCollector(qualifiedName);
@@ -49,24 +50,43 @@ public class ReplaceOnDemandImportIntention extends Intention {
       }
       final PsiClass[] importedClasses = visitor.getImportedClasses();
       Arrays.sort(importedClasses, new PsiClassComparator());
-      final PsiManager manager = importStatement.getManager();
-      final PsiElementFactory factory = JavaPsiFacade.getInstance(manager.getProject()).getElementFactory();
-      final PsiElement importList = importStatement.getParent();
-      for (PsiClass importedClass : importedClasses) {
-        final PsiImportStatement newImportStatement = factory.createImportStatement(importedClass);
-        importList.add(newImportStatement);
-      }
-      new CommentTracker().deleteAndRestoreComments(importStatement);
+      createImportStatements(importStatement, importedClasses, factory::createImportStatement);
     }
     else if (importStatementBase instanceof PsiImportStaticStatement) {
-      // do something else
+      PsiClass targetClass = ((PsiImportStaticStatement)importStatementBase).resolveTargetClass();
+      if (targetClass != null) {
+        String[] members = ImportsUtil.collectReferencesThrough(javaFile,
+                                                                importStatementBase.getImportReference(),
+                                                                (PsiImportStaticStatement)importStatementBase)
+          .stream()
+          .map(PsiReference::resolve)
+          .filter(resolve -> resolve instanceof PsiMember)
+          .map(member -> ((PsiMember)member).getName())
+          .distinct()
+          .filter(Objects::nonNull)
+          .toArray(String[]::new);
+
+        createImportStatements(importStatementBase,
+                               members,
+                               member -> factory.createImportStaticStatement(targetClass, member));
+      }
     }
   }
 
+  private static <T> void createImportStatements(PsiImportStatementBase importStatement,
+                                                 T[] importedMembers,
+                                                 Function<T, PsiImportStatementBase> function) {
+    final PsiElement importList = importStatement.getParent();
+    for (T importedMember : importedMembers) {
+      importList.add(function.apply(importedMember));
+    }
+    new CommentTracker().deleteAndRestoreComments(importStatement);
+  }
+
   private static class ClassCollector extends JavaRecursiveElementWalkingVisitor {
 
     private final String importedPackageName;
-    private final Set<PsiClass> importedClasses = new HashSet();
+    private final Set<PsiClass> importedClasses = new HashSet<>();
 
     ClassCollector(String importedPackageName) {
       this.importedPackageName = importedPackageName;

plugins/IntentionPowerPak/test/com/siyeh/ipp/imports/StaticImport.java

@@ -0,0 +1,7 @@
+import static java.util.Arrays.*;
+class A {
+  void f(String[] array){
+    sort(array);
+    System.out.println(asList(array));
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/imports/StaticImport_after.java

@@ -0,0 +1,9 @@
+import static java.util.Arrays.asList;
+import static java.util.Arrays.sort;
+
+class A {
+  void f(String[] array){
+    sort(array);
+    System.out.println(asList(array));
+  }
+}

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/imports/ReplaceOnDemandImportIntentionTest.java

@@ -0,0 +1,20 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.siyeh.ipp.imports;
+
+import com.siyeh.IntentionPowerPackBundle;
+import com.siyeh.ipp.IPPTestCase;
+
+public class ReplaceOnDemandImportIntentionTest extends IPPTestCase {
+
+  public void testStaticImport() { doTest(); }
+
+  @Override
+  protected String getIntentionName() {
+    return IntentionPowerPackBundle.message("replace.on.demand.import.intention.name");
+  }
+
+  @Override
+  protected String getRelativePath() {
+    return "imports";
+  }
+}