Developer Roadmap: API Clarity and Renderer Stability

This document is the implementation plan for keeping easytable simple for beginners while making internals safer for long-term maintenance.

Current State

easytable() currently does three jobs at once:

1. Parse and transform model results.
2. Render to output-specific objects (flextable or LaTeX string).
3. Optionally write files (export.word, export.csv).

This is convenient, but can be unclear for new users and harder to maintain.

API Rework Plan (Phased)

Phase 1: Keep behavior, improve clarity (current target)

1. Keep easytable() as main user entry point.
2. Improve parameter validation and friendly errors.
3. Document side effects (export.word, export.csv) explicitly.

Phase 2: Introduce explicit workflow functions

Add clearly separated helpers:

1. easytable_build():
   • takes models
   • returns backend-agnostic table spec (display strings + style map)
2. easytable_render():
   • takes spec
   • returns renderer object (flextable, LaTeX)
3. easytable_export():
   • takes rendered object/spec
   • writes files

easytable() remains a convenience wrapper that calls the three steps.

Phase 3: Deprecation policy and migration

1. Keep wrapper stable for beginners.
2. Mark low-level transitions with soft deprecation warnings.
3. Provide migration examples in release notes.

Beginner Navigation Plan

Beginner path should always be:

1. Fit models.
2. Call easytable(...).
3. Optionally add one argument at a time (highlight, control.var, output, exports).

Avoid requiring beginners to understand renderer internals or object classes.

Renderer Adapter Contract

To reduce drift between Word/HTML and LaTeX:

1. Core transformation must own row semantics:
   • coefficient vs model-stat rows
   • control indicator placement
2. Core must own finalized display strings:
   • estimate + stars + (SE) line breaks
3. Renderers must only map style tokens to backend syntax.

External Dependency Change Strategy (example: flextable)

When dependencies evolve:

1. Pin a compatibility floor in DESCRIPTION.
2. Maintain adapter-focused tests in tests/testthat.
3. Avoid deep reliance on undocumented object internals.
4. Keep fallback behavior documented (for missing optional packages).

Compatibility Checklist for Releases

Before each release:

1. Run core tests with devtools::test().
2. Run constrained profile:
   • EASYTABLE_SKIP_WORD_TESTS=true Rscript -e "devtools::test()"
3. Spot-check parity on key invariants:
   • two-line coefficient cells
   • zebra only on coefficient rows
   • one coefficient/stat divider

Design Reference

For design language and contributor guardrails, see DESIGN_PHILOSOPHY.md in the repository root.