@bad-cards/theseus NPM

Theseus

Theseus offers fluent state manipulation and management for JavaScript applications, streamlining state changes with clarity and enforceable rules.

Goals

Clarity in State Management: Ensure that state changes are transparent and understandable.
Ease of Compliance: Encourage adherence to best practices with a design that makes it easier to follow rules than to break them.
Smart, Automatic Typing: Leverage intelligent data typing detection to reduce boilerplate and increase efficiency.

Installation

npm install theseus

Quick Start

A brief introduction on how to get started with Theseus. For example:

import { Evolver, AsyncEvolver } from 'theseus-library';

// Example of using Evolver
const myEvolver = Evolver.as<MyDataType>()
    .withParamName('myData')
    .withMutators({...});

// Example of using AsyncEvolver
const myAsyncEvolver = AsyncEvolver.build<MyAsyncDataType>()
    .named('asyncData')
    .withActions({...});

Core Concepts

Evolvers

Evolvers in Theseus enable flexible state evolution in JavaScript applications, suitable for complex or asynchronous state manipulation. They follow a one-to-many relationship, where one Evolver applies many Mutators. Evolvers always use mutable data and return the same data type, ensuring consistency and predictability in state changes.

Evolver: An Evolver manages synchronous state evolution, integrating multiple Mutators for different aspects of state transformation. It uses mutable data as input and returns the same data type, maintaining state integrity.
```
	- **AsyncEvolver**: Asynchronous version of `Evolver`, containing mutators which always return a promise of the Evolver's data type.
```
Mutator: Mutators are functions within an Evolver, each specifying a unique rule for how the state evolves. They define the logic for state changes, ensuring that each modification is controlled and deliberate.

Refineries

Refineries in Theseus offer structured data transformation, following a one-to-many relationship where one Refinery manages many Forges. Refineries always use immutable data as input, and output any other type.

RefineryComplex: A RefineryComplex manages multiple Refineries, each with their own Forges, enabling interconnected data transformation workflows.
Refinery: A Refinery orchestrates data transformation, using multiple Forges to handle complex data processing tasks.
Forge: Each Forge in a Refinery performs a specific data transformation with immutable input, returning data of some other type.

Flags

Flags in Theseus provide an efficient way to manage binary state representations like bitwise flags or toggles, handling flag enumerations, offering methods for manipulation, testing, and querying of flag values.

Examples - To Do Application

ToDoEvolver

Show a real-world example of using Evolver for state management.

import { Evolver } from 'theseus';

// Evolver for managing a single ToDo
const ToDoEvolver = Evolver.as<ToDo>().withParamName("list").withMutators({
    setTitle: ({mutableList}, newTitle: string) => {
        mutableList.title = newTitle;
        return mutableList;
    },
    setPriority: ({mutableList}, newPriority: number) => {
        mutableList.priority = newPriority;
        return mutableList;
    },
    togglePinned: ({mutableList}) => {
        mutableList.pinned = !mutableList.pinned;
        return mutableList;
    },
    setDescription: ({mutableList}, newDescription: string) => {
        mutableList.description = newDescription;
        return mutableList;
    },
    addListItem: ({mutableList}, listItem: ListItem) => {
        mutableList.listItem = mutableList.listItem || [];
        mutableList.listItem.push(listItem);
        return mutableList;
    },
    removeListItem: ({mutableList}, listItemToRemove: ListItem) => {
        mutableList.listItem = mutableList.listItem.filter(listItem => listItem !== listItemToRemove);
        return mutableList;
    },
    moveItemToSection: ({mutableList}, itemIndex: number, sectionIndex: number) => {
        mutableList.itemToSectionIndexMap[itemIndex] = sectionIndex;
        return mutableList;
    }
});

// Evolver for managing a single Section
const SectionEvolver = Evolver.as<Section>().withParamName("section").withMutators({
    setTitle: ({mutableSection}, newTitle: string) => {
        mutableSection.title = newTitle;
        return mutableSection;
    },
    setType: ({mutableSection}, newType: SectionType) => {
        mutableSection.type = newType;
        return mutableSection;
    },
    updateOrder: ({mutableSection}, newOrder: number[]) => {
        // Assuming mutableSection has a property that keeps track of the order of ToDo items
        mutableSection.itemOrder = newOrder;
        return mutableSection;
    },
    // Additional mutators as needed...
});

// Usage example

const todoId = (new URLSearchParams(location.search)).get("list-id");
const todo: ToDo = async fetchToDoById(todoId); // Fetch a list from the server

const updatedToDo = ToDoEvolver.mutate(myToDo)
    .setTitle('New Title')
    .togglePinned()
    .getFinalForm();