Implement a mechanism to control the output format of Message.toString within a Runnable instance.

PiperOrigin-RevId: 665539414

java/core/BUILD.bazel

@@ -549,6 +549,7 @@ LITE_TEST_EXCLUSIONS = [
     "src/test/java/com/google/protobuf/Proto2ExtensionLookupSchemaTest.java",
     "src/test/java/com/google/protobuf/Proto2SchemaTest.java",
     "src/test/java/com/google/protobuf/Proto2UnknownEnumValueTest.java",
+    "src/test/java/com/google/protobuf/ProtobufToStringOutputTest.java",
     "src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java",
     "src/test/java/com/google/protobuf/ServiceTest.java",
     "src/test/java/com/google/protobuf/SingleFieldBuilderTest.java",

java/core/src/main/java/com/google/protobuf/AbstractMessage.java

@@ -84,8 +84,11 @@ public abstract class AbstractMessage
 
   @Override
   public final String toString() {
-    return TextFormat.printer()
+    TextFormat.Printer printer =
-        .printToString(this, TextFormat.Printer.FieldReporterLevel.ABSTRACT_TO_STRING);
+        ProtobufToStringOutput.shouldOutputDebugFormat()
+            ? TextFormat.debugFormatPrinter()
+            : TextFormat.printer();
+    return printer.printToString(this, TextFormat.Printer.FieldReporterLevel.ABSTRACT_TO_STRING);
   }
 
   @Override

java/core/src/main/java/com/google/protobuf/ProtobufToStringOutput.java

@@ -0,0 +1,52 @@
+package com.google.protobuf;
+
+/**
+ * ProtobufToStringOutput controls the output format of {@link Message#toString()}. Specifically, for
+ * the Runnable object passed to `callWithDebugFormat` and `callWithTextFormat`, Message.toString()
+ * will always output the specified format unless ProtobufToStringOutput is used again to change the
+ * output format.
+ */
+public final class ProtobufToStringOutput {
+  private enum OutputMode {
+    DEBUG_FORMAT,
+    TEXT_FORMAT
+  }
+
+  private static final ThreadLocal<OutputMode> outputMode =
+      new ThreadLocal<OutputMode>() {
+        @Override
+        protected OutputMode initialValue() {
+          return OutputMode.TEXT_FORMAT;
+        }
+      };
+
+  private ProtobufToStringOutput() {}
+
+  @CanIgnoreReturnValue
+  private static OutputMode setOutputMode(OutputMode newMode) {
+    OutputMode oldMode = outputMode.get();
+    outputMode.set(newMode);
+    return oldMode;
+  }
+
+  private static void callWithSpecificFormat(Runnable impl, OutputMode mode) {
+    OutputMode oldMode = setOutputMode(mode);
+    try {
+      impl.run();
+    } finally {
+      OutputMode unused = setOutputMode(oldMode);
+    }
+  }
+
+  public static void callWithDebugFormat(Runnable impl) {
+    callWithSpecificFormat(impl, OutputMode.DEBUG_FORMAT);
+  }
+
+  public static void callWithTextFormat(Runnable impl) {
+    callWithSpecificFormat(impl, OutputMode.TEXT_FORMAT);
+  }
+
+  public static boolean shouldOutputDebugFormat() {
+    return outputMode.get() == OutputMode.DEBUG_FORMAT;
+  }
+}

java/core/src/main/java/com/google/protobuf/TextFormat.java

@@ -111,14 +111,19 @@ public final class TextFormat {
 
   /** Printer instance which escapes non-ASCII characters. */
   public static Printer printer() {
-    return Printer.DEFAULT;
+    return Printer.DEFAULT_TEXT_FORMAT;
+  }
+
+  /** Printer instance which escapes non-ASCII characters and prints in the debug format. */
+  public static Printer debugFormatPrinter() {
+    return Printer.DEFAULT_DEBUG_FORMAT;
   }
 
   /** Helper class for converting protobufs to text. */
   public static final class Printer {
 
-    // Printer instance which escapes non-ASCII characters.
+    // Printer instance which escapes non-ASCII characters and prints in the text format.
-    private static final Printer DEFAULT =
+    private static final Printer DEFAULT_TEXT_FORMAT =
         new Printer(
             true,
             TypeRegistry.getEmptyTypeRegistry(),
@@ -126,6 +131,15 @@ public final class TextFormat {
             false,
             false);
 
+    // Printer instance which escapes non-ASCII characters and prints in the debug format.
+    private static final Printer DEFAULT_DEBUG_FORMAT =
+        new Printer(
+            true,
+            TypeRegistry.getEmptyTypeRegistry(),
+            ExtensionRegistryLite.getEmptyRegistry(),
+            true,
+            false);
+
     /**
      * A list of the public APIs that output human-readable text from a message. A higher-level API
      * must be larger than any lower-level APIs it calls under the hood, e.g

java/core/src/test/java/com/google/protobuf/DebugFormatTest.java

@@ -12,11 +12,11 @@ import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 @RunWith(JUnit4.class)
-public final class DebugFormatTest {
+public class DebugFormatTest {
 
-  private static final String REDACTED_REGEX = "\\[REDACTED\\]";
+  static final String REDACTED_REGEX = "\\[REDACTED\\]";
-  private static final String UNSTABLE_PREFIX_SINGLE_LINE = getUnstablePrefix(true);
+  static final String UNSTABLE_PREFIX_SINGLE_LINE = getUnstablePrefix(true);
-  private static final String UNSTABLE_PREFIX_MULTILINE = getUnstablePrefix(false);
+  static final String UNSTABLE_PREFIX_MULTILINE = getUnstablePrefix(false);
 
   private static String getUnstablePrefix(boolean singleLine) {
     return "";

java/core/src/test/java/com/google/protobuf/ProtobufToStringOutputTest.java

@@ -0,0 +1,103 @@
+package com.google.protobuf;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import protobuf_unittest.UnittestProto.RedactedFields;
+import protobuf_unittest.UnittestProto.TestNestedMessageRedaction;
+import java.util.ArrayList;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public final class ProtobufToStringOutputTest extends DebugFormatTest {
+  RedactedFields message;
+
+  @Before
+  public void setupTest() {
+    message =
+        RedactedFields.newBuilder()
+            .setOptionalUnredactedString("foo")
+            .setOptionalRedactedString("bar")
+            .setOptionalRedactedMessage(
+                TestNestedMessageRedaction.newBuilder().setOptionalUnredactedNestedString("foobar"))
+            .build();
+  }
+
+  @Test
+  public void toStringFormat_defaultFormat() {
+    assertThat(message.toString())
+        .matches(
+            "optional_redacted_string: \"bar\"\n"
+                + "optional_unredacted_string: \"foo\"\n"
+                + "optional_redacted_message \\{\n"
+                + "  optional_unredacted_nested_string: \"foobar\"\n"
+                + "\\}\n");
+  }
+
+  @Test
+  public void toStringFormat_testDebugFormat() {
+    ProtobufToStringOutput.callWithDebugFormat(
+        () ->
+            assertThat(message.toString())
+                .matches(
+                    String.format(
+                        "%soptional_redacted_string: %s\n"
+                            + "optional_unredacted_string: \"foo\"\n"
+                            + "optional_redacted_message \\{\n"
+                            + "  %s\n"
+                            + "\\}\n",
+                        UNSTABLE_PREFIX_MULTILINE, REDACTED_REGEX, REDACTED_REGEX)));
+  }
+
+  @Test
+  public void toStringFormat_testTextFormat() {
+    ProtobufToStringOutput.callWithTextFormat(
+        () -> {
+          assertThat(message.toString())
+              .matches(
+                  "optional_redacted_string: \"bar\"\n"
+                      + "optional_unredacted_string: \"foo\"\n"
+                      + "optional_redacted_message \\{\n"
+                      + "  optional_unredacted_nested_string: \"foobar\"\n"
+                      + "\\}\n");
+        });
+  }
+
+  @Test
+  public void toStringFormat_testProtoWrapperWithDebugFormat() {
+    ProtobufToStringOutput.callWithDebugFormat(
+        () -> {
+          ArrayList<RedactedFields> list = new ArrayList<>();
+          list.add(message);
+          assertThat(list.toString())
+              .matches(
+                  String.format(
+                      "\\[%soptional_redacted_string: %s\n"
+                          + "optional_unredacted_string: \"foo\"\n"
+                          + "optional_redacted_message \\{\n"
+                          + "  %s\n"
+                          + "\\}\n"
+                          + "\\]",
+                      UNSTABLE_PREFIX_MULTILINE, REDACTED_REGEX, REDACTED_REGEX));
+        });
+  }
+
+  @Test
+  public void toStringFormat_testProtoWrapperWithTextFormat() {
+    ProtobufToStringOutput.callWithTextFormat(
+        () -> {
+          ArrayList<RedactedFields> list = new ArrayList<>();
+          list.add(message);
+          assertThat(list.toString())
+              .matches(
+                  "\\[optional_redacted_string: \"bar\"\n"
+                      + "optional_unredacted_string: \"foo\"\n"
+                      + "optional_redacted_message \\{\n"
+                      + "  optional_unredacted_nested_string: \"foobar\"\n"
+                      + "\\}\n"
+                      + "\\]");
+        });
+  }
+}