Update all tests to use text blocks

All `CompilationTestHelper` and `BugCheckerRefactoringTestHelper` test code is now specified using a single text block. These changes were automated thanks to the new text block support added to the `ErrorProneTestHelperSourceFormat` check.
2026-03-10 08:11:25 +00:00 · 2022-08-14 14:36:15 +02:00
parent 24636372c8
commit 13a1cd2f4b
7 changed files with 452 additions and 54 deletions
--- a/README.md
+++ b/README.md
@@ -233,6 +233,12 @@ Other highly relevant commands:
  against _all_ code in the current working directory. For more information
  check the [PIT Maven plugin][pitest-maven].

+The `BugChecker` implementations provided by this project are tested using
+Error Prone's `CompilationTestHelper` and `BugCheckerRefactoringTestHelper`
+classes. These utilities accept text blocks containing inline Java source code.
+To ease modification of this inline source code, consider using IntelliJ IDEA's
+[language injection][idea-language-injection] feature.
+
 ## 💡 How it works

 This project provides additional [`BugChecker`][error-prone-bugchecker]
@@ -268,6 +274,7 @@ channel; please see our [security policy][security] for details.
 [github-actions-build-badge]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/build.yml/badge.svg
 [github-actions-build-master]: https://github.com/PicnicSupermarket/error-prone-support/actions/workflows/build.yml?query=branch:master&event=push
 [google-java-format]: https://github.com/google/google-java-format
+[idea-language-injection]: https://www.jetbrains.com/help/idea/using-language-injections.html
 [license-badge]: https://img.shields.io/github/license/PicnicSupermarket/error-prone-support
 [license]: https://github.com/PicnicSupermarket/error-prone-support/blob/master/LICENSE.md
 [maven-central-badge]: https://img.shields.io/maven-central/v/tech.picnic.error-prone-support/error-prone-support?color=blue
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/ErrorProneTestHelperSourceFormat.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/ErrorProneTestHelperSourceFormat.java
@@ -6,19 +6,24 @@ import static com.google.errorprone.BugPattern.StandardTags.STYLE;
 import static com.google.errorprone.matchers.Matchers.anyOf;
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
+import static com.sun.tools.javac.util.Position.NOPOS;
 import static java.util.stream.Collectors.joining;
 import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;

 import com.google.auto.service.AutoService;
+import com.google.common.base.CharMatcher;
 import com.google.common.base.Splitter;
 import com.google.errorprone.BugPattern;
+import com.google.errorprone.ErrorProneFlags;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
 import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.suppliers.Supplier;
 import com.google.errorprone.util.ASTHelpers;
+import com.google.errorprone.util.SourceVersion;
 import com.google.googlejavaformat.java.Formatter;
 import com.google.googlejavaformat.java.FormatterException;
 import com.google.googlejavaformat.java.ImportOrderer;
@@ -27,9 +32,12 @@ import com.google.googlejavaformat.java.RemoveUnusedImports;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.Tree;
-import com.sun.tools.javac.util.Position;
+import com.sun.tools.javac.api.MultiTaskListener;
+import com.sun.tools.javac.util.Context;
 import java.util.List;
 import java.util.Optional;
+import javax.inject.Inject;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;

 /**
 * A {@link BugChecker} that flags improperly formatted Error Prone test code.
@@ -45,20 +53,33 @@ import java.util.Optional;
 * are not able to) remove imports that become obsolete as a result of applying their suggested
 * fix(es).
 */
-// XXX: Once we target JDK 17 (optionally?) suggest text block fixes.
+// XXX: The check does not flag well-formatted text blocks with insufficient indentation. Cover this
+// using an generic check or wait for Google Java Format support (see
+// https://github.com/google/google-java-format/issues/883#issuecomment-1404336418).
+// XXX: The check does not flag well-formatted text blocks with excess indentation.
+// XXX: ^ Validate this claim.
 // XXX: GJF guesses the line separator to be used by inspecting the source. When using text blocks
 // this may cause the current unconditional use of `\n` not to be sufficient when building on
 // Windows; TBD.
+// XXX: Forward compatibility: ignore "malformed" code in tests that, based on an
+// `@DisabledForJreRange` or `@EnableForJreRange` annotation, target a Java runtime greater than the
+// current runtime.
@AutoService(BugChecker.class)
@BugPattern(
-    summary = "Test code should follow the Google Java style",
+    summary =
+        "Test code should follow the Google Java style (and when targeting JDK 15+ be "
+            + "specified using a single text block)",
    link = BUG_PATTERNS_BASE_URL + "ErrorProneTestHelperSourceFormat",
    linkType = CUSTOM,
    severity = SUGGESTION,
    tags = STYLE)
+// XXX: Drop suppression if/when the `avoidTextBlocks` field is dropped.
+@SuppressWarnings("java:S2160" /* Super class equality definition suffices. */)
 public final class ErrorProneTestHelperSourceFormat extends BugChecker
    implements MethodInvocationTreeMatcher {
  private static final long serialVersionUID = 1L;
+  private static final String FLAG_AVOID_TEXT_BLOCKS =
+      "ErrorProneTestHelperSourceFormat:AvoidTextBlocks";
  private static final Formatter FORMATTER = new Formatter();
  private static final Matcher<ExpressionTree> INPUT_SOURCE_ACCEPTING_METHOD =
      anyOf(
@@ -77,9 +98,31 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
      instanceMethod()
          .onDescendantOf("com.google.errorprone.BugCheckerRefactoringTestHelper.ExpectOutput")
          .named("addOutputLines");
+  private static final Supplier<Boolean> IS_JABEL_ENABLED =
+      VisitorState.memoize(ErrorProneTestHelperSourceFormat::isJabelEnabled);
+  // XXX: Proper name for this?
+  // XXX: Something about tabs.
+  private static final String TEXT_BLOCK_MARKER = "\"\"\"";
+  private static final String TEXT_BLOCK_LINE_SEPARATOR = "\n";
+  private static final String DEFAULT_TEXT_BLOCK_INDENTATION = " ".repeat(12);
+  private static final String METHOD_SELECT_ARGUMENT_RELATIVE_INDENTATION = " ".repeat(8);

-  /** Instantiates a new {@link ErrorProneTestHelperSourceFormat} instance. */
-  public ErrorProneTestHelperSourceFormat() {}
+  private final boolean avoidTextBlocks;
+
+  /** Instantiates a default {@link ErrorProneTestHelperSourceFormat} instance. */
+  public ErrorProneTestHelperSourceFormat() {
+    this(ErrorProneFlags.empty());
+  }
+
+  /**
+   * Instantiates a customized {@link ErrorProneTestHelperSourceFormat}.
+   *
+   * @param flags Any provided command line flags.
+   */
+  @Inject
+  ErrorProneTestHelperSourceFormat(ErrorProneFlags flags) {
+    avoidTextBlocks = flags.getBoolean(FLAG_AVOID_TEXT_BLOCKS).orElse(Boolean.FALSE);
+  }

  @Override
  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
@@ -95,22 +138,23 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
      return buildDescription(tree).setMessage("No source code provided").build();
    }

-    int startPos = ASTHelpers.getStartPosition(sourceLines.get(0));
-    int endPos = state.getEndPosition(sourceLines.get(sourceLines.size() - 1));
-
    /* Attempt to format the source code only if it fully consists of constant expressions. */
    return getConstantSourceCode(sourceLines)
-        .map(source -> flagFormattingIssues(startPos, endPos, source, isOutputSource, state))
+        .map(source -> flagFormattingIssues(sourceLines, source, isOutputSource, state))
        .orElse(Description.NO_MATCH);
  }

  private Description flagFormattingIssues(
-      int startPos, int endPos, String source, boolean retainUnusedImports, VisitorState state) {
-    Tree methodInvocation = state.getPath().getLeaf();
+      List<? extends ExpressionTree> sourceLines,
+      String source,
+      boolean retainUnusedImports,
+      VisitorState state) {
+    MethodInvocationTree methodInvocation = (MethodInvocationTree) state.getPath().getLeaf();

    String formatted;
    try {
-      formatted = formatSourceCode(source, retainUnusedImports).trim();
+      String gjfResult = formatSourceCode(source, retainUnusedImports);
+      formatted = canUseTextBlocks(sourceLines, state) ? gjfResult : gjfResult.stripTrailing();
    } catch (
        @SuppressWarnings("java:S1166" /* Stack trace not relevant. */)
        FormatterException e) {
@@ -119,31 +163,113 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
          .build();
    }

-    if (source.trim().equals(formatted)) {
+    boolean isFormatted = source.equals(formatted);
+    boolean hasStringLiteralMismatch = shouldUpdateStringLiteralFormat(sourceLines, state);
+
+    if (isFormatted && !hasStringLiteralMismatch) {
      return Description.NO_MATCH;
    }

-    if (startPos == Position.NOPOS || endPos == Position.NOPOS) {
-      /*
-       * We have insufficient source information to emit a fix, so we only flag the fact that the
-       * code isn't properly formatted.
-       */
-      return describeMatch(methodInvocation);
-    }
+    int startPos = ASTHelpers.getStartPosition(sourceLines.get(0));
+    int endPos = state.getEndPosition(sourceLines.get(sourceLines.size() - 1));
+    boolean hasNewlineMismatch =
+        !isFormatted && source.stripTrailing().equals(formatted.stripTrailing());

    /*
-     * The code isn't properly formatted; replace all lines with the properly formatted
-     * alternatives.
+     * The source code is not properly formatted and/or not specified using a single text block.
+     * Report the more salient of the violations, and suggest a fix if sufficient source information
+     * is available.
     */
-    return describeMatch(
-        methodInvocation,
-        SuggestedFix.replace(
-            startPos,
-            endPos,
-            Splitter.on(System.lineSeparator())
-                .splitToStream(formatted)
-                .map(state::getConstantExpression)
-                .collect(joining(", "))));
+    boolean isTextBlockUsageIssue = isFormatted || (hasNewlineMismatch && hasStringLiteralMismatch);
+    boolean canSuggestFix = startPos != NOPOS && endPos != NOPOS;
+    return buildDescription(methodInvocation)
+        .setMessage(
+            isTextBlockUsageIssue
+                ? String.format(
+                    "Test code should %sbe specified using a single text block",
+                    avoidTextBlocks ? "not " : "")
+                : String.format(
+                    "Test code should follow the Google Java style%s",
+                    hasNewlineMismatch ? " (pay attention to trailing newlines)" : ""))
+        .addFix(
+            canSuggestFix
+                ? SuggestedFix.replace(
+                    startPos,
+                    endPos,
+                    canUseTextBlocks(sourceLines, state)
+                        ? toTextBlockExpression(methodInvocation, formatted, state)
+                        : toLineEnumeration(formatted, state))
+                : SuggestedFix.emptyFix())
+        .build();
+  }
+
+  private boolean shouldUpdateStringLiteralFormat(
+      List<? extends ExpressionTree> sourceLines, VisitorState state) {
+    return canUseTextBlocks(sourceLines, state)
+        ? (sourceLines.size() > 1 || !SourceCode.isTextBlock(sourceLines.get(0), state))
+        : sourceLines.stream().anyMatch(tree -> SourceCode.isTextBlock(tree, state));
+  }
+
+  private boolean canUseTextBlocks(List<? extends ExpressionTree> sourceLines, VisitorState state) {
+    return !avoidTextBlocks
+        && (SourceVersion.supportsTextBlocks(state.context)
+            || IS_JABEL_ENABLED.get(state)
+            || sourceLines.stream().anyMatch(line -> SourceCode.isTextBlock(line, state)));
+  }
+
+  private static String toTextBlockExpression(
+      MethodInvocationTree tree, String source, VisitorState state) {
+    String indentation = suggestTextBlockIndentation(tree, state);
+
+    // XXX: Verify trailing """ on new line.
+    return TEXT_BLOCK_MARKER
+        + System.lineSeparator()
+        + indentation
+        + source
+            .replace(TEXT_BLOCK_LINE_SEPARATOR, System.lineSeparator() + indentation)
+            .replace("\\", "\\\\")
+            .replace(TEXT_BLOCK_MARKER, "\"\"\\\"")
+        + TEXT_BLOCK_MARKER;
+  }
+
+  private static String toLineEnumeration(String source, VisitorState state) {
+    return Splitter.on(TEXT_BLOCK_LINE_SEPARATOR)
+        .splitToStream(source)
+        .map(state::getConstantExpression)
+        .collect(joining(", "));
+  }
+
+  // XXX: This makes certain assumptions; document these.
+  private static String suggestTextBlockIndentation(
+      MethodInvocationTree target, VisitorState state) {
+    CharSequence sourceCode = state.getSourceCode();
+    if (sourceCode == null) {
+      return DEFAULT_TEXT_BLOCK_INDENTATION;
+    }
+
+    String source = sourceCode.toString();
+    return getIndentation(target.getArguments().get(1), source)
+        .or(() -> getIndentation(target.getArguments().get(0), source))
+        .or(
+            () ->
+                getIndentation(target.getMethodSelect(), source)
+                    .map(METHOD_SELECT_ARGUMENT_RELATIVE_INDENTATION::concat))
+        .orElse(DEFAULT_TEXT_BLOCK_INDENTATION);
+  }
+
+  private static Optional<String> getIndentation(Tree tree, String source) {
+    int startPos = ASTHelpers.getStartPosition(tree);
+    if (startPos == NOPOS) {
+      return Optional.empty();
+    }
+
+    int finalNewLine = source.lastIndexOf(System.lineSeparator(), startPos);
+    if (finalNewLine < 0) {
+      return Optional.empty();
+    }
+
+    return Optional.of(source.substring(finalNewLine + 1, startPos))
+        .filter(CharMatcher.whitespace()::matchesAllOf);
  }

  private static String formatSourceCode(String source, boolean retainUnusedImports)
@@ -162,14 +288,29 @@ public final class ErrorProneTestHelperSourceFormat extends BugChecker
    StringBuilder source = new StringBuilder();

    for (ExpressionTree sourceLine : sourceLines) {
+      if (source.length() > 0) {
+        source.append(TEXT_BLOCK_LINE_SEPARATOR);
+      }
+
      String value = ASTHelpers.constValue(sourceLine, String.class);
      if (value == null) {
        return Optional.empty();
      }

-      source.append(value).append(System.lineSeparator());
+      source.append(value);
    }

    return Optional.of(source.toString());
  }
+
+  /**
+   * Tells whether Jabel appears to be enabled, indicating that text blocks are supported, even if
+   * may <em>appear</em> that they {@link SourceVersion#supportsTextBlocks(Context) aren't}.
+   *
+   * @see <a href="https://github.com/bsideup/jabel">Jabel</a>
+   */
+  private static boolean isJabelEnabled(VisitorState state) {
+    return MultiTaskListener.instance(state.context).getTaskListeners().stream()
+        .anyMatch(listener -> listener.toString().contains("com.github.bsideup.jabel"));
+  }
 }
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/SourceCode.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/SourceCode.java
@@ -12,6 +12,7 @@ import com.google.errorprone.VisitorState;
 import com.google.errorprone.fixes.SuggestedFix;
 import com.google.errorprone.util.ErrorProneToken;
 import com.google.errorprone.util.ErrorProneTokens;
+import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.Tree;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
@@ -26,8 +27,30 @@ public final class SourceCode {
  /** The complement of {@link CharMatcher#whitespace()}. */
  private static final CharMatcher NON_WHITESPACE_MATCHER = CharMatcher.whitespace().negate();

+  // XXX: Proper name for this?
+  private static final String TEXT_BLOCK_MARKER = "\"\"\"";
+
  private SourceCode() {}

+  /**
+   * Tells whether the given expression is a text block.
+   *
+   * @param tree The AST node of interest.
+   * @param state A {@link VisitorState} describing the context in which the given {@link
+   *     ExpressionTree} is found.
+   * @return {@code true} iff the given expression is a text block.
+   */
+  // XXX: Add tests!
+  public static boolean isTextBlock(ExpressionTree tree, VisitorState state) {
+    if (tree.getKind() != Tree.Kind.STRING_LITERAL) {
+      return false;
+    }
+
+    /* If the source code is unavailable then we assume that this literal is _not_ a text block. */
+    String src = state.getSourceForNode(tree);
+    return src != null && src.startsWith(TEXT_BLOCK_MARKER);
+  }
+
  /**
   * Returns a string representation of the given {@link Tree}, preferring the original source code
   * (if available) over its prettified representation.
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/ThirdPartyLibrary.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/util/ThirdPartyLibrary.java
@@ -75,8 +75,12 @@ public enum ThirdPartyLibrary {
   *
   * <p>The {@link VisitorState}'s symbol table is consulted first. If the type has not yet been
   * loaded, then an attempt is made to do so.
+   *
+   * @param className The type of interest.
+   * @param state The context under consideration.
+   * @return {@code true} iff the indicated type is on the classpath.
   */
-  private static boolean isKnownClass(String className, VisitorState state) {
+  public static boolean isKnownClass(String className, VisitorState state) {
    return state.getTypeFromString(className) != null || canLoadClass(className, state);
  }

--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/ErrorProneTestHelperSourceFormatTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/ErrorProneTestHelperSourceFormatTest.java
@@ -4,8 +4,15 @@ import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;

 final class ErrorProneTestHelperSourceFormatTest {
+  // XXX: Add tests cases for `ErrorProneTestHelperSourceFormat:IgnoreMalformedCode`.
+  // XXX: Consider reducing the `@DisabledForJreRange(max = JRE.JAVA_14)` test scope by moving the
+  // text blocks to smaller test methods.
+
+  @DisabledForJreRange(max = JRE.JAVA_14)
  @Test
  void identification() {
    CompilationTestHelper.newInstance(ErrorProneTestHelperSourceFormat.class, getClass())
@@ -17,13 +24,70 @@ final class ErrorProneTestHelperSourceFormatTest {
            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
            "",
            "class A {",
-            "  private final CompilationTestHelper compilationTestHelper =",
-            "      CompilationTestHelper.newInstance(EmptyMethod.class, getClass());",
-            "  private final BugCheckerRefactoringTestHelper refactoringTestHelper =",
-            "      BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass());",
-            "",
            "  void m() {",
-            "    compilationTestHelper",
+            "    CompilationTestHelper.newInstance(EmptyMethod.class, getClass())",
+            "        // BUG: Diagnostic contains: No source code provided",
+            "        .addSourceLines(\"A.java\")",
+            "        // BUG: Diagnostic contains: Source code is malformed:",
+            "        .addSourceLines(\"B.java\", \"class B {\")",
+            "        // BUG: Diagnostic contains: Test code should be specified using a single text block",
+            "        .addSourceLines(\"C.java\", \"class C {}\")",
+            "        // Malformed code, but not compile-time constant, so not flagged.",
+            "        .addSourceLines(\"D.java\", \"class D {\" + getClass())",
+            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
+            "        .addSourceLines(\"E.java\", \"class E { }\")",
+            "        // Well-formed code, so not flagged.",
+            "        .addSourceLines(\"F.java\", \"\"\"",
+            "               class F {}",
+            "               \"\"\")",
+            "        // BUG: Diagnostic contains: Test code should follow the Google Java style (pay attention to",
+            "        // trailing newlines)",
+            "        .addSourceLines(\"G.java\", \"\"\"",
+            "               class G {}\"\"\")",
+            "        .doTest();",
+            "",
+            "    BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass())",
+            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
+            "        .addInputLines(\"in/A.java\", \"class A { }\")",
+            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
+            "        .addOutputLines(\"out/A.java\", \"class A { }\")",
+            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
+            "        .addInputLines(",
+            "            \"in/B.java\",",
+            "            \"\"\"",
+            "            import java.util.Map;",
+            "",
+            "            class B {}",
+            "            \"\"\")",
+            "        // Unused import, but in an output file, so not flagged.",
+            "        .addOutputLines(",
+            "            \"out/B.java\",",
+            "            \"\"\"",
+            "            import java.util.Map;",
+            "",
+            "            class B {}",
+            "            \"\"\")",
+            "        .doTest(TestMode.TEXT_MATCH);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @DisabledForJreRange(max = JRE.JAVA_14)
+  @Test
+  void identificationAvoidTextBlocks() {
+    CompilationTestHelper.newInstance(ErrorProneTestHelperSourceFormat.class, getClass())
+        .setArgs("-XepOpt:ErrorProneTestHelperSourceFormat:AvoidTextBlocks=true")
+        .addSourceLines(
+            "A.java",
+            "import com.google.errorprone.BugCheckerRefactoringTestHelper;",
+            "import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;",
+            "import com.google.errorprone.CompilationTestHelper;",
+            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    CompilationTestHelper.newInstance(EmptyMethod.class, getClass())",
            "        // BUG: Diagnostic contains: No source code provided",
            "        .addSourceLines(\"A.java\")",
            "        // BUG: Diagnostic contains: Source code is malformed:",
@@ -34,9 +98,16 @@ final class ErrorProneTestHelperSourceFormatTest {
            "        .addSourceLines(\"D.java\", \"class D {\" + getClass())",
            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
            "        .addSourceLines(\"E.java\", \"class E { }\")",
+            "        // BUG: Diagnostic contains: Test code should not be specified using a single text block",
+            "        .addSourceLines(\"F.java\", \"\"\"",
+            "        class F {}",
+            "        \"\"\")",
+            "        // BUG: Diagnostic contains: Test code should follow the Google Java style (pay attention to",
+            "        // trailing newlines)",
+            "        .addSourceLines(\"G.java\", \"class G {}\", \"\")",
            "        .doTest();",
            "",
-            "    refactoringTestHelper",
+            "    BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass())",
            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
            "        .addInputLines(\"A.java\", \"class A { }\")",
            "        // BUG: Diagnostic contains: Test code should follow the Google Java style",
@@ -51,11 +122,14 @@ final class ErrorProneTestHelperSourceFormatTest {
        .doTest();
  }

+  // XXX: Add `replacement` test.
+  @DisabledForJreRange(max = JRE.JAVA_14)
  @Test
  void replacement() {
    /*
     * Verifies that import sorting and code formatting is performed unconditionally, while unused
     * imports are removed unless part of a `BugCheckerRefactoringTestHelper` expected output file.
+     * Also verifies that text blocks are properly indented.
     */
    BugCheckerRefactoringTestHelper.newInstance(ErrorProneTestHelperSourceFormat.class, getClass())
        .addInputLines(
@@ -66,13 +140,104 @@ final class ErrorProneTestHelperSourceFormatTest {
            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
            "",
            "class A {",
-            "  private final CompilationTestHelper compilationTestHelper =",
-            "      CompilationTestHelper.newInstance(EmptyMethod.class, getClass());",
-            "  private final BugCheckerRefactoringTestHelper refactoringTestHelper =",
-            "      BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass());",
-            "",
            "  void m() {",
-            "    compilationTestHelper",
+            "    CompilationTestHelper.newInstance(EmptyMethod.class, getClass())",
+            "        .addSourceLines(",
+            "            \"A.java\",",
+            "            \"\"\"",
+            "            import java.util.Map;",
+            "            import java.util.Collection;",
+            "            import java.util.List;",
+            "",
+            "            interface A extends List<A>, Map<A,A> { }\"\"\")",
+            "        .addSourceLines(\"B.java\", \"class B {}\")",
+            "        .doTest();",
+            "",
+            "    BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass())",
+            "        .addInputLines(",
+            "            \"in/A.java\",",
+            "            \"\"\"",
+            "            import java.util.Map;",
+            "            import java.util.Collection;",
+            "            import java.util.List;",
+            "",
+            "            interface A extends List<A>, Map<A,A> { }\"\"\")",
+            "        .addOutputLines(",
+            "            \"out/A.java\",",
+            "            \"\"\"",
+            "            import java.util.Map;",
+            "            import java.util.Collection;",
+            "            import java.util.List;",
+            "",
+            "            interface A extends List<A>, Map<A,A> { }\"\"\")",
+            "        .doTest(TestMode.TEXT_MATCH);",
+            "  }",
+            "}")
+        .addOutputLines(
+            "out/A.java",
+            "import com.google.errorprone.BugCheckerRefactoringTestHelper;",
+            "import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;",
+            "import com.google.errorprone.CompilationTestHelper;",
+            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    CompilationTestHelper.newInstance(EmptyMethod.class, getClass())",
+            "        .addSourceLines(",
+            "            \"A.java\",",
+            "            \"\"\"",
+            "            import java.util.List;",
+            "            import java.util.Map;",
+            "",
+            "            interface A extends List<A>, Map<A, A> {}",
+            "            \"\"\")",
+            "        .addSourceLines(\"B.java\", \"\"\"",
+            "            class B {}",
+            "            \"\"\")",
+            "        .doTest();",
+            "",
+            "    BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass())",
+            "        .addInputLines(",
+            "            \"in/A.java\",",
+            "            \"\"\"",
+            "            import java.util.List;",
+            "            import java.util.Map;",
+            "",
+            "            interface A extends List<A>, Map<A, A> {}",
+            "            \"\"\")",
+            "        .addOutputLines(",
+            "            \"out/A.java\",",
+            "            \"\"\"",
+            "            import java.util.Collection;",
+            "            import java.util.List;",
+            "            import java.util.Map;",
+            "",
+            "            interface A extends List<A>, Map<A, A> {}",
+            "            \"\"\")",
+            "        .doTest(TestMode.TEXT_MATCH);",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+
+  @Test
+  void replacementAvoidTextBlocks() {
+    /*
+     * Verifies that import sorting and code formatting is performed unconditionally, while unused
+     * imports are removed unless part of a `BugCheckerRefactoringTestHelper` expected output file.
+     */
+    BugCheckerRefactoringTestHelper.newInstance(ErrorProneTestHelperSourceFormat.class, getClass())
+        .setArgs("-XepOpt:ErrorProneTestHelperSourceFormat:AvoidTextBlocks=true")
+        .addInputLines(
+            "in/A.java",
+            "import com.google.errorprone.BugCheckerRefactoringTestHelper;",
+            "import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;",
+            "import com.google.errorprone.CompilationTestHelper;",
+            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
+            "",
+            "class A {",
+            "  void m() {",
+            "    CompilationTestHelper.newInstance(EmptyMethod.class, getClass())",
            "        .addSourceLines(",
            "            \"A.java\",",
            "            \"import java.util.Map;\",",
@@ -82,7 +247,7 @@ final class ErrorProneTestHelperSourceFormatTest {
            "            \"interface A extends List<A>, Map<A,A> { }\")",
            "        .doTest();",
            "",
-            "    refactoringTestHelper",
+            "    BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass())",
            "        .addInputLines(",
            "            \"A.java\",",
            "            \"import java.util.Map;\",",
@@ -108,13 +273,8 @@ final class ErrorProneTestHelperSourceFormatTest {
            "import tech.picnic.errorprone.bugpatterns.EmptyMethod;",
            "",
            "class A {",
-            "  private final CompilationTestHelper compilationTestHelper =",
-            "      CompilationTestHelper.newInstance(EmptyMethod.class, getClass());",
-            "  private final BugCheckerRefactoringTestHelper refactoringTestHelper =",
-            "      BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass());",
-            "",
            "  void m() {",
-            "    compilationTestHelper",
+            "    CompilationTestHelper.newInstance(EmptyMethod.class, getClass())",
            "        .addSourceLines(",
            "            \"A.java\",",
            "            \"import java.util.List;\",",
@@ -123,7 +283,7 @@ final class ErrorProneTestHelperSourceFormatTest {
            "            \"interface A extends List<A>, Map<A, A> {}\")",
            "        .doTest();",
            "",
-            "    refactoringTestHelper",
+            "    BugCheckerRefactoringTestHelper.newInstance(EmptyMethod.class, getClass())",
            "        .addInputLines(",
            "            \"A.java\",",
            "            \"import java.util.List;\",",
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/util/SourceCodeTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/util/SourceCodeTest.java
@@ -5,21 +5,52 @@ import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
 import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
 import com.google.errorprone.BugPattern;
+import com.google.errorprone.CompilationTestHelper;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.bugpatterns.BugChecker.AnnotationTreeMatcher;
 import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
 import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
+import com.google.errorprone.bugpatterns.BugChecker.ReturnTreeMatcher;
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.AnnotationTree;
+import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.ReturnTree;
 import com.sun.source.tree.Tree;
 import javax.lang.model.element.Name;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;

 final class SourceCodeTest {
+  @DisabledForJreRange(max = JRE.JAVA_14)
+  @Test
+  void isTextBlock() {
+    CompilationTestHelper.newInstance(TextBlockFlagger.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "class A {",
+            "  String negative1() {",
+            "    return toString();",
+            "  }",
+            "",
+            "  String negative2() {",
+            "    return \"foo\";",
+            "  }",
+            "",
+            "  String positive1() {",
+            "    // BUG: Diagnostic contains:",
+            "    return \"\"\"",
+            "    foo",
+            "    \"\"\";",
+            "  }",
+            "}")
+        .doTest();
+  }
+
  @Test
  void deleteWithTrailingWhitespaceAnnotations() {
    BugCheckerRefactoringTestHelper.newInstance(
@@ -228,6 +259,22 @@ final class SourceCodeTest {
        .doTest(TestMode.TEXT_MATCH);
  }

+  /**
+   * A {@link BugChecker} that delegates to {@link SourceCode#isTextBlock(ExpressionTree,
+   * VisitorState)}.
+   */
+  @BugPattern(summary = "Interacts with `SourceCode` for testing purposes", severity = ERROR)
+  public static final class TextBlockFlagger extends BugChecker implements ReturnTreeMatcher {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public Description matchReturn(ReturnTree tree, VisitorState state) {
+      return SourceCode.isTextBlock(tree.getExpression(), state)
+          ? describeMatch(tree)
+          : Description.NO_MATCH;
+    }
+  }
+
  /**
   * A {@link BugChecker} that uses {@link SourceCode#deleteWithTrailingWhitespace(Tree,
   * VisitorState)} to suggest the deletion of annotations and methods with a name containing
--- a/to-11.sh
+++ b/to-11.sh
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+set -e -u -o pipefail
+
+# XXX: Clean this up.
+# XXX: Drop this class.
+mvn clean test-compile fmt:format \
+  -s "$(dirname "${0}")/settings.xml" \
+  -T 1.0C \
+  -Perror-prone \
+  -Perror-prone-fork \
+  -Ppatch \
+  -Pself-check \
+  -Derror-prone.patch-checks=ErrorProneTestHelperSourceFormat \
+  -Derror-prone.self-check-args='-XepOpt:ErrorProneTestHelperSourceFormat:AvoidTextBlocks=true -XepDisableAllChecks' \
+  -Dverification.skip