ts-mixer

library6.0.4jsnpmunverified

ts-mixer is a lightweight TypeScript library designed to provide robust mixin functionality, addressing common pitfalls found in other mixin implementations. It enables developers to compose classes through a multiple-inheritance-like mechanism, supporting complex scenarios such as mixing classes that extend other classes, abstract classes (TypeScript >= 4.2), and generic classes (with specific caveats). The current stable version is 6.0.4. The project appears to follow a release cadence driven by feature development and bug fixes, as indicated by its conventional commits usage. Key differentiators include its ability to support static, protected, and private properties, as well as a more resilient approach to constructor complexities and decorator usage compared to simple function-returning-class solutions. It offers different mixing strategies, including ES6 proxies and hard copies, providing flexibility for various use cases.

type-stubs

npm install ts-mixer

github ↗package ↗

INSTALL

IMPORT

SIG · TS-MIXER

ts-mixer

type-stubsjavascriptv6.0.4

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Mixin

✓ import { Mixin } from 'ts-mixer';

✗ const Mixin = require('ts-mixer').Mixin;

Primary export for combining classes. Use named import for ESM. CommonJS environments should use `require` for interoperability, though the library is primarily designed for modern TypeScript/ESM.

mix

✓ import { mix } from 'ts-mixer';

✗ import mix from 'ts-mixer';

Used specifically for mixing generic classes and leverages declaration merging. It's a named export, not a default.

hasMixin

✓ import { hasMixin } from 'ts-mixer';

✗ someInstance instanceof SomeMixin;

Replacement for `instanceof` checks with ts-mixer mixins. Requires ES6 `Map` or a polyfill.

Demonstrates basic class mixing with `ts-mixer` to combine functionalities from multiple base classes into a new derived class.

import { Mixin } from 'ts-mixer'; class Foo { protected makeFoo() { return 'foo'; } } class Bar { protected makeBar() { return 'bar'; } } class FooBar extends Mixin(Foo, Bar) { public makeFooBar() { return this.makeFoo() + this.makeBar(); } } const fooBar = new FooBar(); console.log(fooBar.makeFooBar());

Debug

Known issues

gotchaDirect `instanceof` checks will not work correctly with classes mixed using `ts-mixer`. The library provides a `hasMixin` function as a replacement.

fix

Use `hasMixin(instance, MixinClass)` instead of `instance instanceof MixinClass`.

affects: >=1.0.0

gotchaWhen mixing generic classes, a more cumbersome notation using the `mix` function and TypeScript's declaration merging is required due to TypeScript limitations.

fix

Refer to the 'Mixing Generic Classes' section in the documentation for the correct `mix` function usage pattern.

affects: >=1.0.0

gotchaApplying decorators to mixed classes also requires a specific, more verbose notation. Standard decorator application might not work as expected.

fix

Consult the 'Mixing with Decorators' section in the `ts-mixer` documentation for the correct usage pattern.

affects: >=1.0.0

gotchaES6 constructors cannot be called without `new`, which prevents `ts-mixer` from reliably passing the proper `this` context to base class constructors. This can affect how constructor logic behaves.

fix

Review the 'Dealing with Constructors' section in the documentation for workarounds and understanding potential impacts on your constructor logic.

affects: >=1.0.0

gotchaCertain features like `@decorator` and `hasMixin` rely on ES6 `Map`. If targeting environments older than ES6, you must provide a polyfill for `Map`.

fix

Ensure `Map` is available in your runtime environment, either natively (ES6+) or through a polyfill.

affects: >=1.0.0

Errors

Common errors & fixes

Base class expressions cannot reference class type parameters.

Attempting to mix generic classes using the standard `Mixin` function or without proper declaration merging.

fix

Use the `mix` function provided by `ts-mixer` in conjunction with TypeScript's declaration merging to properly handle generic class mixing.

TypeError: Right-hand side of 'instanceof' is not an object

Trying to use `instanceof` with a class that was created using `ts-mixer`, which modifies the prototype chain in a way incompatible with native `instanceof`.

fix

Replace `instanceof` checks with `ts-mixer`'s `hasMixin(instance, MixinClass)` utility function.

Upgrade

Version history

6.0.4latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

36 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/tannerntannern/ts-mixer ↗

packagehttps://www.npmjs.com/package/ts-mixer ↗