README.md

GraphCompose Testing

io.github.demchaav:graph-compose-testing

Consumer testing support: deterministic layout-snapshot assertions and PDF visual regression (pixel-diff of rendered pages). Add it at test scope to lock the output of documents you generate.

When to depend on it

Add it (test scope) when you want to catch layout/visual regressions in your own documents. Not needed at runtime; not bundled by any published artifact.

Not sufficient on its own. Opening a DocumentSession resolves a FontMetricsProvider, and graph-compose-render-pdf is the only artifact that publishes one — so a classpath without it fails at create() with MissingBackendException, PDFBox on the classpath notwithstanding. Add graph-compose-render-pdf at test scope too, or depend on graph-compose.

Smallest complete example

One session, both gates — the layout assertion needs no render, the visual one takes the rendered bytes:

try (DocumentSession doc = GraphCompose.document().create()) {
    doc.pageFlow().addParagraph("Hello").build();

    // Layout snapshot — asserts the renderer-neutral layout graph is unchanged.
    LayoutSnapshotAssertions.assertMatches(doc.layoutSnapshot(), "invoice-basic");

    // Visual regression — pixel-diffs the rendered pages against a committed baseline.
    PdfVisualRegression.standard().assertMatchesBaseline("invoice-basic", doc.toPdfBytes());
}

Update baselines deliberately with the documented system properties (LayoutSnapshotAssertions.UPDATE_PROPERTY / PdfVisualRegression.APPROVE_PROPERTY).

Install

Same version as the rest of the GraphCompose train (lockstep):

<dependency>
    <groupId>io.github.demchaav</groupId>
    <artifactId>graph-compose-testing</artifactId>
    <version>2.1.0</version>
    <scope>test</scope>
</dependency>

dependencies { testImplementation("io.github.demchaav:graph-compose-testing:2.1.0") }

The full "which artifact?" table: root README → Installation. Upgrading from 1.x: modules migration guide.