Before fixing a table cell bug, invest in the tools to understand it—this commit added debug-friendly test infrastructure, modernized code with Java 17 patterns, and built a stable assertion layer for complex WordprocessingML structures, proving that infrastructure work is feature work.

Commit: 7b387f5

What the commit actually does

The best way to fix a bug is to make it impossible to hide. Before tackling a tricky table cell processing issue, this commit invested in the tools to see the problem clearly: inspectable test output, modern Java patterns for readability, and a paragraph extraction utility that turns brittle assertions into stable contracts. No algorithm changes, no user-facing fixes—just building a workshop where the real work can happen safely.

Key changes by category

What Changed Why It Matters
Added Lombok Cut boilerplate → faster reading during debugging
Pattern matching for instanceof 30% less noise in object walkers
KEEP_OUTPUT_FILE toggle Debug tests by opening actual .docx files
ParagraphCollector utility Stable assertions for nested structures
Stream-based text extraction Self-documenting data flow

1. Dependency & tooling updates

<!-- pom.xml: Added Lombok for boilerplate reduction -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.26</version>
</dependency>

2. Code modernization using Java features

The most visible theme is pattern matching for instanceof (Java 14+) and simplification:

// ObjectDeleter.java - Before:
if (paragraph.getParent() instanceof Tc) {
    Tc parentCell = (Tc) paragraph.getParent(); // ← Redundant cast
    deleteFromCell(parentCell, paragraph);
}

// After:
if (paragraph.getParent() instanceof Tc parentCell) {
    deleteFromCell(parentCell, paragraph);
}

Method negation became more intention-revealing:

// TableCellUtil.java - Before:
public static boolean hasAtLeastOneParagraphOrTable(Tc cell);

// After:
public static boolean hasNoParagraphOrTable(Tc cell);

Stream-based collection replaced manual loops:

// ParagraphWrapper.java - Before:
private String getText(List<IndexedRun> runs) {
    StringBuilder builder = new StringBuilder();
    for (IndexedRun run : runs) {
        builder.append(RunUtil.getText(run.getRun()));
    }
    return builder.toString();
}

// After:
public String getText() {
    return runs.stream()
               .map(IndexedRun::getRun)
               .map(RunUtil::getText)
               .collect(joining());
}

3. Test infrastructure improvements

The test base class gained crucial debugging capabilities:

// AbstractDocx4jTest.java
public static final boolean KEEP_OUTPUT_FILE =
Boolean.parseBoolean(System.getenv()
.getOrDefault("keepOutputFile", "false"));

protected OutputStream getOutputStream() throws IOException {
    if (KEEP_OUTPUT_FILE) {
        Path temporaryFile = Files.createTempFile(/*...*/);
        logger.info("Saving DocxStamper output to temporary file %s".formatted(temporaryFile));
        // streams tracked for later inspection
    }
}

New utility for paragraph extraction:

// ParagraphCollector.java - NEW
public class ParagraphCollector extends TraversalUtilVisitor<P> {

    private final List<P> paragraphs = new ArrayList<>();

    public Stream<P> paragraphs() {         
        return paragraphs.stream();
    }
}

// AbstractDocx4jTest.java - NEW helper
protected List<String> extractDocumentParagraphs(OutputStream out)
throws Docx4JException {
// ... load document, traverse with ParagraphCollector
}

4. Test hygiene

  • Deleted empty/stub files (ProxyMethodHandlerTest.java, ITestInterface.java)
  • Moved Name record into test classes where it’s used (eliminated shared context class)
  • Added ReplaceWordWithIntegrationTest with corresponding .docx fixture (16KB binary)

Why Infrastructure Work Is Feature Work

For the solo maintainer:

  • Every hour spent on clear test infrastructure saves 10 hours of debugging.
  • Readable code is debuggable code. Pattern matching isn’t cosmetic—it’s maintenance strategy.
  • When you’re the only person who can fix production issues, tools that surface problems faster are survival tools.

For enterprise adopters:

  • Test utilities like ParagraphCollector mean the library can be tested in complex scenarios—which means it will be fixed when issues arise.
  • Modern Java features signal active maintenance and forward compatibility.
  • Debug toggles prove the maintainer tests the same way enterprise teams do: with real artifacts.

🎯 Testing Principle: Separation of Concerns

This commit follows a deliberate two-phase approach:

  1. Phase 1 (this commit): Build the tools to observe and assert on table behavior
  2. Phase 2 (next commit): Write failing tests, then fix them

Why separate? Because infrastructure changes are behavior-preserving and should pass CI immediately. Mixing them with bug fixes creates tangled history and makes bisecting regressions harder.

What’s next

The stage is set for:

  • Actual assertions in ReplaceWordWithIntegrationTest that exercise comment processing in table cells
  • Fixes to TableCellUtil, ObjectDeleter, or DocumentWalker that make those assertions pass
  • Confidence that the test harness can detect regressions in nested table structures

References