Add a --skip-removing-unused-imports flag to disable unused import removal

MOE_MIGRATED_REVID=142208872

Author: cushon

core/src/main/java/com/google/googlejavaformat/java/CommandLineOptions.java

@@ -37,6 +37,7 @@ final class CommandLineOptions {
   private final boolean fixImportsOnly;
   private final boolean removeJavadocOnlyImports;
   private final boolean sortImports;
+  private final boolean removeUnusedImports;
 
   CommandLineOptions(
       ImmutableList<String> files,
@@ -50,7 +51,8 @@ final class CommandLineOptions {
       boolean stdin,
       boolean fixImportsOnly,
       boolean removeJavadocOnlyImports,
-      boolean sortImports) {
+      boolean sortImports,
+      boolean removeUnusedImports) {
     this.files = files;
     this.inPlace = inPlace;
     this.lines = lines;
@@ -63,6 +65,7 @@ final class CommandLineOptions {
     this.fixImportsOnly = fixImportsOnly;
     this.removeJavadocOnlyImports = removeJavadocOnlyImports;
     this.sortImports = sortImports;
+    this.removeUnusedImports = removeUnusedImports;
   }
 
   /** The files to format. */
@@ -128,6 +131,11 @@ boolean sortImports() {
     return sortImports;
   }
 
+  /** Remove unused imports. */
+  boolean removeUnusedImports() {
+    return removeUnusedImports;
+  }
+
   /** Returns true if partial formatting was selected. */
   boolean isSelection() {
     return !lines().isEmpty() || !offsets().isEmpty() || !lengths().isEmpty();
@@ -151,6 +159,7 @@ static class Builder {
     private Boolean fixImportsOnly = false;
     private Boolean removeJavadocOnlyImports = false;
     private Boolean sortImports = true;
+    private Boolean removeUnusedImports = true;
 
     ImmutableList.Builder<String> filesBuilder() {
       return files;
@@ -210,6 +219,11 @@ Builder sortImports(boolean sortImports) {
       return this;
     }
 
+    Builder removeUnusedImports(boolean removeUnusedImports) {
+      this.removeUnusedImports = removeUnusedImports;
+      return this;
+    }
+
     CommandLineOptions build() {
       return new CommandLineOptions(
           this.files.build(),
@@ -223,7 +237,8 @@ CommandLineOptions build() {
           this.stdin,
           this.fixImportsOnly,
           this.removeJavadocOnlyImports,
-          this.sortImports);
+          this.sortImports,
+          this.removeUnusedImports);
     }
   }
 }

core/src/main/java/com/google/googlejavaformat/java/CommandLineOptionsParser.java

@@ -92,6 +92,9 @@ static CommandLineOptions parse(Iterable<String> options) {
         case "--skip-sorting-imports":
           optionsBuilder.sortImports(false);
           break;
+        case "--skip-removing-unused-imports":
+          optionsBuilder.removeUnusedImports(false);
+          break;
         case "-":
           optionsBuilder.stdin(true);
           break;

core/src/main/java/com/google/googlejavaformat/java/FormatFileCallable.java

@@ -49,12 +49,14 @@ public String call() throws FormatterException {
   }
 
   private String fixImports(String input) throws FormatterException {
-    input =
-        RemoveUnusedImports.removeUnusedImports(
-            input,
-            parameters.removeJavadocOnlyImports()
-                ? JavadocOnlyImports.REMOVE
-                : JavadocOnlyImports.KEEP);
+    if (parameters.removeUnusedImports()) {
+      input =
+          RemoveUnusedImports.removeUnusedImports(
+              input,
+              parameters.removeJavadocOnlyImports()
+                  ? JavadocOnlyImports.REMOVE
+                  : JavadocOnlyImports.KEEP);
+    }
     if (parameters.sortImports()) {
       input = ImportOrderer.reorderImports(input);
     }

core/src/main/java/com/google/googlejavaformat/java/UsageException.java

@@ -42,6 +42,8 @@ public final class UsageException extends Exception {
     "    Fix import order and remove any unused imports, but do no other formatting.",
     "  --skip-sorting-imports",
     "    Do not fix the import order. Unused imports will still be removed.",
+    "  --skip-removing-unused-imports",
+    "    Do not remove unused imports. Imports will still be sorted.",
     "  --length, -length",
     "    Character length to format.",
     "  --lines, -lines, --line, -line",

core/src/test/java/com/google/googlejavaformat/java/CommandLineOptionsParserTest.java

@@ -41,6 +41,7 @@ public void defaults() {
     assertThat(options.inPlace()).isFalse();
     assertThat(options.version()).isFalse();
     assertThat(options.sortImports()).isTrue();
+    assertThat(options.removeUnusedImports()).isTrue();
   }
 
   @Test
@@ -112,8 +113,15 @@ public void version() {
   @Test
   public void skipSortingImports() {
     assertThat(
-            CommandLineOptionsParser.parse(Arrays.asList("--skip-sorting-imports"))
-                .sortImports())
+            CommandLineOptionsParser.parse(Arrays.asList("--skip-sorting-imports")).sortImports())
+        .isFalse();
+  }
+
+  @Test
+  public void skipRemovingUnusedImports() {
+    assertThat(
+            CommandLineOptionsParser.parse(Arrays.asList("--skip-removing-unused-imports"))
+                .removeUnusedImports())
         .isFalse();
   }
 

core/src/test/java/com/google/googlejavaformat/java/FormatterTest.java

@@ -263,7 +263,14 @@ public void importOrderingAndFormatting() throws IOException, UsageException {
   public void formattingWithoutImportOrdering() throws IOException, UsageException {
     importOrdering(
         "--skip-sorting-imports",
-        "com/google/googlejavaformat/java/testimports/A.formatting-only");
+        "com/google/googlejavaformat/java/testimports/A.formatting-and-unused-import-removal");
+  }
+
+  @Test
+  public void formattingWithoutRemovingUnusedImports() throws IOException, UsageException {
+    importOrdering(
+        "--skip-removing-unused-imports",
+        "com/google/googlejavaformat/java/testimports/A.formatting-and-import-sorting");
   }
 
   private void importOrdering(String sortArg, String outputResourceName)

core/src/test/resources/com/google/googlejavaformat/java/testimports/A.formatting-and-import-sorting

@@ -0,0 +1,29 @@
+package com.google.example;
+
+import static com.google.truth.Truth.assertThat;
+import static org.junit.Assert.fail;
+
+import com.google.common.base.Preconditions;
+import java.util.List;
+import java.util.Set;
+import javax.annotations.Nullable;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class SomeTest {
+
+  <T> void check(@Nullable List<T> x) {
+    Preconditions.checkNodeNull(x);
+  }
+
+  void f() {
+    List<String> xs = null;
+    assertThat(xs).isNull();
+    try {
+      check(xs);
+      fail();
+    } catch (NullPointerException e) {
+    }
+  }
+}

core/src/test/resources/com/google/googlejavaformat/java/testimports/A.formatting-and-unused-import-removal

@@ -0,0 +1,31 @@
+package com.google.example;
+
+import com.google.common.base.Preconditions;
+
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.util.List;
+
+import javax.annotations.Nullable;
+
+import static org.junit.Assert.fail;
+import static com.google.truth.Truth.assertThat;
+
+@RunWith(JUnit4.class)
+public class SomeTest {
+
+  <T> void check(@Nullable List<T> x) {
+    Preconditions.checkNodeNull(x);
+  }
+
+  void f() {
+    List<String> xs = null;
+    assertThat(xs).isNull();
+    try {
+      check(xs);
+      fail();
+    } catch (NullPointerException e) {
+    }
+  }
+}