# OpenSpec Change: enterprise-compress-svg

- **Change ID**: enterprise-compress-svg
- **Package**: `@suaveplan/compress-svg`
- **Category**: universal
- **Target path**: `universal/compression/compress-svg`
- **Status**: PROPOSED
- **Date**: 2026-04-24
- **Reference spec**: `/mnt/s/web/suaveplan/enterprise/compress-svg.md`

---

## Summary

Deliver `@suaveplan/compress-svg` on the genesis branch from scratch at enterprise quality. The package provides SVG optimisation and minification: whitespace removal, redundant attribute stripping, path data precision reduction, element collapsing, ID mangling, viewBox normalisation, inline style to attribute conversion, and SVGO-compatible plugin pipeline. Pure TypeScript, runs in Bun/Node/browser, operates on SVG string input/output.

---

## Current-state audit (genesis)

The package does not exist on genesis yet — this is a fresh build. No prior source, no test results, no coverage data. The main-branch package had 99.31% coverage.

---

## Available workspace deps on genesis

| Package | Role |
|---|---|
| `@suaveplan/error` (`workspace:^`) | Base class for `SvgCompressError`; `SVG_COMPRESS.*` codes |
| `@suaveplan/types` (`workspace:^`) | `LoggerLike` |
| `zod` (`catalog:forms`) | Zod schemas for all public option types |
| `@opentelemetry/api` (`catalog:observability`) | Spans + counters |

Dev deps: `vitest`, `@vitest/coverage-istanbul`, `fast-check`, `mitata` (all `catalog:testing`).

---

## Public API

### Core types

```ts
class SvgCompressError extends SuaveplanError

interface SvgPlugin {
  name: string
  apply(node: SvgNode, options: SvgPluginOptions): SvgNode | null
}

interface SvgNode {
  type: 'element' | 'text' | 'comment' | 'cdata' | 'doctype'
  name?: string
  attributes?: Record<string, string>
  children?: SvgNode[]
  value?: string
}

interface CompressOptions {
  plugins?: SvgPlugin[]          // default: standard plugin set
  floatPrecision?: number        // decimal places for path coords; default: 3
  transformPrecision?: number    // default: 5
  multipass?: boolean            // default: true; run until stable
  removeComments?: boolean       // default: true
  removeMetadata?: boolean       // default: true
  removeDoctype?: boolean        // default: true
  collapseGroups?: boolean       // default: true
  mergeStyles?: boolean          // default: true
  mangleIds?: boolean            // default: false
}

interface CompressResult {
  data: string                   // optimised SVG string
  originalSize: number           // bytes
  compressedSize: number         // bytes
  ratio: number                  // compressedSize / originalSize
  passCount: number              // multipass iterations used
}

function compressSvg(svg: string, options?: CompressOptions): CompressResult
function parseSvg(svg: string): SvgNode
function serializeSvg(node: SvgNode): string

// Built-in plugins (each independently importable)
const removeComments: SvgPlugin
const removeMetadata: SvgPlugin
const removeDoctype: SvgPlugin
const collapseGroups: SvgPlugin
const cleanupAttrs: SvgPlugin
const convertColors: SvgPlugin
const convertPathData: SvgPlugin
const convertTransforms: SvgPlugin
const mergeStyles: SvgPlugin
const inlineStyles: SvgPlugin
const removeUnusedDefs: SvgPlugin
const mangleIds: SvgPlugin
```

### Presets

```ts
const PRESET_DEFAULT: SvgPlugin[]    // removeComments + metadata + doctype + collapseGroups + cleanupAttrs + convertPathData
const PRESET_SAFE: SvgPlugin[]       // PRESET_DEFAULT minus id-mangling and transform conversion
const PRESET_AGGRESSIVE: SvgPlugin[] // all plugins enabled
```

### Error codes

```ts
type SvgCompressErrorCode =
  | 'SVG_COMPRESS_PARSE_FAILED'
  | 'SVG_COMPRESS_INVALID_SVG'
  | 'SVG_COMPRESS_PLUGIN_FAILED'

const SVG_COMPRESS_ERROR_METADATA: Readonly<Record<SvgCompressErrorCode, CodeMetadata>>
function registerSvgCompressErrorCodes(): void
```

### Zod schemas

```ts
CompressOptionsSchema
CompressResultSchema
```

---

## New additions for genesis

1. **Streaming-safe parser** — lightweight push-parser (no DOMParser dependency) operating on string; SAX-like for large SVGs.
2. **Plugin pipeline** — each plugin receives and returns an `SvgNode` tree; returning `null` removes the node. Plugins compose cleanly via standard array.
3. **Multipass loop** — runs plugins until the serialised output reaches a stable size (or `multipass: false`).
4. **OTel instrumentation** — span `svg.compress`, counter `svg_compress_total`, histogram `svg_compress_duration_ms` + `svg_compress_ratio`.
5. **Property-based tests** — compression idempotency (compress twice = same output), `parseSvg` ↔ `serializeSvg` round-trip, ratio always ≤ 1 for any valid SVG.
6. **Benchmark suite** — `compressSvg` on 10 kB SVG icon, 100 kB complex illustration, 1 MB map SVG.

---

## File layout

```text
universal/compression/compress-svg/
  package.json
  tsconfig.json
  vitest.config.ts
  src/
    index.ts
    error-codes.ts
    constants/
      index.ts
    types/
      common.ts
      common.md
    core/
      compress-svg/
        compress-svg.ts
        compress-svg.md
        compress-svg.types.ts
        compress-svg.test.ts
        index.ts
    parser/
      svg-parser/
        svg-parser.ts
        svg-parser.md
        svg-parser.test.ts
        index.ts
    plugins/
      remove-comments/
        remove-comments.ts
        remove-comments.md
        remove-comments.test.ts
        index.ts
      remove-metadata/
        remove-metadata.ts
        remove-metadata.md
        remove-metadata.test.ts
        index.ts
      collapse-groups/
        collapse-groups.ts
        collapse-groups.md
        collapse-groups.test.ts
        index.ts
      cleanup-attrs/
        cleanup-attrs.ts
        cleanup-attrs.md
        cleanup-attrs.test.ts
        index.ts
      convert-path-data/
        convert-path-data.ts
        convert-path-data.md
        convert-path-data.test.ts
        index.ts
      convert-transforms/
        convert-transforms.ts
        convert-transforms.md
        convert-transforms.test.ts
        index.ts
      mangle-ids/
        mangle-ids.ts
        mangle-ids.md
        mangle-ids.test.ts
        index.ts
    presets/
      index.ts
    __benchmarks__/
      compress-svg.bench.ts
  tests/
    integration.test.ts
    property.test.ts
```

---

## Impact

**Downstream**: build pipeline tools, `@suaveplan/packer`, any SVG-heavy asset pipelines.
**Breaking changes**: none — fresh build.
**Prerequisites**: `@suaveplan/error`, `@suaveplan/types` published to Verdaccio.