Modernizes supergroup for Vue.js applications by providing reactive composables with full TypeScript support and generic type inference, while preserving the legacy lodash mixin API.

Architecture

New Composables (src/composables/ - TypeScript)

• useGrouping - Core reactive grouping with auto-update on data changes
• useGroupList - List operations (lookup, tree navigation, D3 conversion)
• useGroupValue - Value operations (paths, aggregates, siblings)
• useGroupSelection - Non-mutating state management

TypeScript Features

• Full generic type inference - return types automatically match input data types
• Compile-time type checking for dimension field names
• Complete .d.ts type definitions exported
• 175 lines of comprehensive type definitions in src/types.ts

Module Strategy

• TypeScript source in src/ compiled to ES modules in dist/
• Legacy supergroup.cjs for CommonJS compatibility
• Dual exports in package.json support both seamlessly
• Type definitions included for full IDE support

Usage

// Vue 3 composables with TypeScript (new)
import { ref } from 'vue';
import { useGrouping, useGroupSelection } from 'supergroup/composables';

interface Employee {
  name: string;
  department: string;
  salary: number;
}

const data = ref<Employee[]>([...]);

// Generic type inference - fully typed to Employee!
const { grouped, lookup, leafNodes } = useGrouping(data, ['department', 'name']);
const selection = useGroupSelection(grouped);

// Type-safe - TypeScript validates field names at compile time
const dept = lookup('Engineering'); // Type: GroupValue<Employee> | undefined

// Legacy API (unchanged)
const _ = require('supergroup');
const groups = _.supergroup(data, ['category', 'subcategory']);

Backward Compatibility

• All 30 existing tests pass unchanged
• Legacy API completely untouched
• No breaking changes
• JavaScript users can use the library without TypeScript

Testing

• 43/43 tests passing (30 legacy + 13 new)
• TypeScript compilation: ✅ No errors
• CodeQL: 0 vulnerabilities
• Reactivity verified across all composables
• Type definitions validated

Documentation

• COMPOSABLES.md - Full API reference with TypeScript examples
• examples/VueComponent.vue - Working example
• README.md - Updated with TypeScript usage examples
• Complete type exports for all public APIs

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.