As v3 of office-stamper settles in, I’ve turned my attention to the foundation that keeps the project stable: the test suite. Over the years, the test package had accumulated a significant amount of “helper” debt. This month, I’ve deleted over 12,000 lines of code, most of it redundant test utilities.

The Problem: The “Helper” Bloat

In the early days of the fork, I relied on TestDocxStamper and various IOStreams utilities to handle the boilerplate of loading a template, stamping it, and extracting the result for assertion. While this worked, it created a separate “test API” that I had to maintain alongside the real one.

Worse, many tests were using stampAndLoadAndExtract calls that hid the actual flow of the engine. It was hard to see exactly where a failure occurred—was it the loading, the stamping, or the extraction?

The Solution: Functional Assertions with Stringifier

The API refactoring of OfficeStamper (which now returns the document directly) opened the door for a much cleaner test flow.

Instead of opaque helpers, tests now follow a transparent, functional pattern:

  1. Load the resource using standard utilities.
  2. Stamp using a factory-provided stamper.
  3. Assert using the new Stringifier utility.
// Modern v3 test flow
var template = getWordResource("Template.docx");
var stamped = OfficeStampers.docxPackageStamper().stamp(template, context);
var content = Stringifier.stringifyWord(stamped);

assertThat(content).contains("Expected Value");

1. OfficeStampers Factory

I’ve introduced OfficeStampers as a central point for creating configured stampers in tests. This ensures that tests are always using the same configuration defaults as production code, reducing “it works in tests but not in prod” surprises.

2. Stringifier for Content Assertions

The Stringifier.stringifyWord utility is a game-changer for characterization tests. It provides a stable, text-based representation of a DOCX document’s content, making it trivial to use standard AssertJ or JUnit assertions. It completely replaces the old, fragile extraction logic.

Impact: Maintenance at Scale

By removing TestDocxStamper, IOStreams, and ThrowingSupplier, I’ve reduced the maintenance surface of the project’s test module by nearly 40%.

  • Faster Builds: Fewer classes to compile and simpler test flows mean the CI pipeline is snappier. It also makes automated dependency updates—like the recent Renovate bump of JavaFX 26-ea+21—completely transparent and risk-free.
  • Clarity: New contributors (and future-Joseph) can read a test and see exactly how the library is being used, without having to navigate through layers of test-only abstractions.
  • Consistency: The same OfficeStamper interface is used in the library, in the CLI, and in the tests.

Next Steps

With the test suite modernized, I’m now looking at expanding the characterization test coverage for Excel and PowerPoint, applying the same Stringifier pattern to ensure structural fidelity across all supported formats.

December 29th 2025 — Commit Summary:

  • Refactor: Deleted TestDocxStamper and 12k lines of legacy test utilities.
  • Feat: Introduced OfficeStampers factory for consistent test configuration.
  • Feat: Implemented Stringifier.stringifyWord for simplified document assertions.
  • Refactor: Migrated all engine tests to the new functional test flow.