Pure TypeScript barcode/QR generation with 9 formats, PNG renderer, and XLSX embedding. Full codebase audit with critical bug fixes. 437 tests (157 Rust + 280 TypeScript).

• 9 barcode formats — Code 39, Code 128, EAN-13, UPC-A, ITF-14, GS1-128, QR Code, Data Matrix, PDF417
• renderBarcodePNG() — pure TypeScript PNG renderer (no external dependencies)
• generateBarcode() — one-call XLSX embedding with drawing XML and relationships
• generateDrawingXml() / generateDrawingRels() — low-level drawing XML generation
• Multi-image accumulation — multiple images per sheet without data loss

• Unicode panic — validate.rs byte-indexing multi-byte characters → chars().take(n).collect()
• Multi-image data loss — addImage() now accumulates via Maps instead of overwriting drawing XML
• SST insert performance — Entry API replaces double hash lookup in shared_strings.rs
• Comments author dedup — Entry::Vacant pattern eliminates double lookup in comments.rs
• DXF diagonal attrs — eliminated redundant UTF-8 decoding in styles.rs

• GF(256) lookup tables hoisted to module-level constants (Data Matrix encoder)
• Array.prototype.at(-1) for O(1) sorted-array access (utils.ts, style-builder.ts)
• split_once(':') replaces split(':').collect::<Vec<>>() in validators
• Single TextEncoder instance in QR encoder (was creating two)

• All docs updated for v0.3.0 accuracy
• Barcode generation examples in playground
• Migration guides updated with barcode comparison

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Browser-first release with IIFE bundle, CDN distribution, Web Worker support, and framework examples. 419 tests (171 Rust + 248 TypeScript).

• IIFE build — self-contained modern-xlsx.min.js (~29 KB) exposing window.ModernXlsx
• CDN distribution — available on jsDelivr and unpkg, no bundler required
• detectWasmUrl() — auto-detection of WASM binary URL from document.currentScript.src
• initWasmSync(module) — synchronous WASM initialization from pre-loaded buffer
• ensureReady() — lazy auto-initialization on first use (cached Promise pattern)
• Source maps — .map files generated for all build outputs (ESM, IIFE, Worker)

• createXlsxWorker() — off-thread XLSX read/write via Web Worker message passing
• modern-xlsx.worker.js — dedicated worker script with auto WASM init
• Transferable buffers — zero-copy transfer of Uint8Array results back to main thread

• tsdown 3-build config — ESM (primary), IIFE (browser), Worker (off-thread)
• Package exports — "." (ESM), "./browser" (IIFE), "./worker" (Worker script)
• browser / unpkg / jsdelivr fields in package.json for CDN auto-resolution

• Interactive browser playground at docs/site/playground.html
• 6 built-in examples: Hello World, Styled Workbook, Read & Inspect, Batch Data, JSON to Sheet, Formulas & Dates
• Live WASM status indicator, Ctrl+Enter execution, download integration

• React — hooks-based integration with useEffect WASM init
• Vue 3 — Composition API with onMounted WASM init
• Svelte 5 — $effect rune-based WASM init
• Angular — service-based WASM init with standalone components

• Cloudflare Workers — XLSX generation at the edge
• Deno Deploy — server-side XLSX with Deno-native imports
• Service Worker — offline XLSX generation with custom WASM URL

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Complete 0.1.x hardening series. 419 tests (171 Rust + 248 TypeScript).

• Style roundtrip: gradient fills, diagonal borders, DXF styles, cell named styles
• Formula metadata: array formulas, shared formulas, formulaRef, sharedIndex
• Feature roundtrip: hyperlinks, comments, data validation, conditional formatting, sheet protection, page setup
• Edge cases: empty workbooks, malformed XML, boundary values
• Error handling: corrupted files, invalid inputs, graceful degradation
• Streaming & benchmarks: 100K row read/write, parallel parsing, buffer scaling
• Utilities: cell refs, dates, format codes, CSV/HTML/JSON conversion

• push_entity() — zero-allocation XML entity resolution
• Vec::with_capacity() on all XML parse buffers (11 sites)
• from_utf8().unwrap_or_default() replaces from_utf8_lossy() (6 sites)
• entries.remove() in StreamingReader — moves data instead of cloning
• drain() in collect_preserved() — moves preserved entries
• #[non_exhaustive] on error enum

• Module-scoped CELL_REF_RE regex (hoisted from hot loop)
• isolatedDeclarations: true in tsconfig
• Shared WASM init via __tests__/setup.ts

• Migration guide: SheetJS
• Migration guide: ExcelJS
• Usage examples cookbook
• Release roadmap

• GitHub Actions pinned to stable versions
• Rust toolchain: @stable
• Node.js engine: >=24.0.0

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First public release.

• Full XLSX read/write with Rust WASM core
• Cell styling — fonts, fills, borders, alignment, number formats via StyleBuilder
• Data validation — list, number, date, text length, custom formula
• Conditional formatting — color scales, data bars, icon sets, formula-based rules
• Frozen panes, hyperlinks, comments, sheet protection, page setup
• Rich text with RichTextBuilder
• Named ranges, document properties, workbook views, calc chain
• Streaming reader/writer for large files
• Parallel sheet parsing (rayon)
• Cell reference utilities, date utilities, format utilities
• Sheet conversion utilities (JSON, CSV, HTML, array-of-arrays)
• Browser Blob download support
• 342 tests (170 Rust + 172 TypeScript)

Operation	modern-xlsx	SheetJS CE	Factor
Read 100K	1,155 ms	4,927 ms	4.3x faster
Write 100K	5,048 ms	5,048 ms	1.0x
sheetToJson 10K	54 ms	103 ms	1.9x faster