Options-defaults design pattern implementation for reliable configuration. It merges objects deeply, overrides arrays and classes (different than Object) and the result remains strongly typed.
2. Usage
3. Features
npm i ts-options-defaults
``ts
import { defaults } from 'ts-options-defaults';
export interface ISomeOptions {
logger?: Partial
}
export class Something {
static defaults = {
logger: console,
};
options: ISomeOptions & typeof Something.defaults;
constructor(options?: ISomeOptions) {
this.options = defaults(Rat.defaults, options);
}
}
`
`ts
import { defaults } from 'ts-options-defaults';
class TestLogger {
constructor(public name = TestLogger) {}
log() {
console.log(Call from ${this.name});
}
}
const someDefaults = {
console,
nested: {
property: 'default',
shouldBeDefault: 'default',
array: ['default1', 'default2'],
},
};
const someOptions = {
nested: {
property: 'overriden',
array: ['overriden1'],
},
array: ['overriden'],
};
const options = defaults(
someDefaults,
someOptions,
{
console: {
log: () => {
console.log(TEST);
},
},
},
{
console: new TestLogger(),
},
);
options.console.log(log); // "Call from TestLogger"debug
options.console.debug(); // "debug"
// options will be:
{
"nested": {
"property": "overriden",
"shouldBeDefault": "default",
"array": [
"overriden1"
]
},
"array": [
"overriden"
]
}
// someDefaults will not be mutated!
`
Beats alternatives - better alternative to {...defaults, ...options} destructing and lodash _.defaults or _.merge`
Secure - immune to prototype pollution attack
Simple - just 40 lines of clean TypeScript code
Strongly typed - result remains strongly typed