Changelog

0.5.1 - 2026-07-10

Merge.merge/1 now rejects malformed classic PDF input with an :invalid_pdf_input diagnostic rather than producing an empty PDF or raising.
NativeElixirPdfUtilities.Tokenizer now emits explicit error tokens for unterminated literal and hexadecimal strings.
Text.extract/2 rejects malformed token streams with an :invalid_pdf_input diagnostic. It also ignores unusually large ToUnicode CMaps to bound memory and CPU use during extraction.

Fixed merge crashes caused by malformed tokens, incomplete streams, duplicate object identifiers, and invalid object identifiers.
Fixed merged PDFs losing inherited /MediaBox and /Resources values from intermediate /Pages tree nodes.
Fixed remapping of non-page /Parent references during a merge.
Fixed malformed TTF font input causing HTML-to-PDF rendering to crash.
Reduced avoidable repeated binary and list copying while writing larger PDFs.

Added NativeElixirPdfUtilities.Diagnostics as the shared public diagnostic contract.
Added standardized diagnostic details for merge, text extraction, HTML rendering, pagination, PDF writing, and file failures.
Added developer guidance for using the shared diagnostics contract in future public APIs.
Added a diagnostics guide under docs/.

Changed Merge.merge/1 to return diagnostic errors instead of raising for empty input.
Changed recoverable failures from merge, text extraction, HTML rendering, pagination, PDF writing, and file operations to return {:error, {reason, diagnostic}} with :stage, :reason, :message, :operation, :module, and :source context when available.

Added a Chromium-backed browser parity test suite for the supported HTML/CSS rendering surface.
Added browser parity fixtures for common layout, CSS cascade, tables, flexbox, grid, pagination, image, link, unit, and production-document scenarios.
Added browser parity coverage documentation so supported renderer behavior is tied to explicit fixtures.

Improved HTML-to-PDF browser accuracy for nested table, flexbox, and grid compositions.
Improved collapsed table border sizing and painting to better match browser output.
Improved @page handling in parity tests so native and Chromium renders use the same page size and margins.
Updated contribution guidance to require focused tests and browser parity coverage for visible HTML-to-PDF feature work.

Fixed CSS custom property resolution inside supported compound values such as padding and side-specific borders.
Fixed box-sizing: border-box handling across block, flex, grid, table, and image layout paths.
Fixed table layout inside flex and grid items, and flex layout directly inside table cells.
Fixed declared table row heights and pagination metadata propagation for table rows.
Fixed pagination edge cases around first-page parent padding, overlapping parent/child groups, and zero-height metadata groups.

Added NativeElixirPdfUtilities.HtmlToPdf, a native HTML/CSS to PDF renderer for document-oriented templates.
Added support for common document HTML including text, headings, paragraphs, spans, lists, links, tables, images, and nested document structure.
Added support for common print-oriented CSS including cascade handling, box model sizing, text styling, borders, backgrounds, tables, flexbox, grid, page sizes, page breaks, and @media print behavior.
Added embedded image, SVG rasterization, and custom TTF font rendering support for generated PDFs.
Added multi-page pagination and PDF writing for rendered HTML documents.
Added detailed render diagnostics for invalid HTML, unsupported HTML, invalid CSS, invalid layout, and invalid document failures.
Added fixture coverage for purchase orders, material requisitions, stock stickers, and trim cards with realistic scrambled data.
Added dedicated HTML-to-PDF compatibility and examples documentation.

Added embedded text extraction so callers can consume readable text data from PDF binaries.

Refactored tokenizer, merge, and text internals to use explicit case/cond branching instead of guarded multi-head private functions.
Split tests into focused tokenizer, merge, and text suites.
Improved package documentation and HexDocs metadata for the release.