Typed Path


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---

Overview

This small utility helps to extract type information from a TypeScript class, interface or type to use it in your code.

Example:

``js
import {typedPath} from 'typed-path';

type TestType = {
a: {
testFunc: () => {result: string};
b: {
arrayOfArrays: string[][];
c: {
d: number;
};
}[];
};
};

console.log(typedPath().a.b[5].c.d.$rawPath);
/*
Outputs
["a", "b", 5, "c", "d"]

*/
`
Please see other path access methods and how to add custom path access methods below.

The utility might also be used to add type protection to such methods as _.get, _.map, _.set, R.pluck from libraries like lodash, ramda.

It is recommended, though, to use optional chaining instead.


---

Features

$3

With typed-path, typescript can check paths and warns you about errors.

![](http://res.cloudinary.com/daren64mz/image/upload/v1487457505/tp-refactoring_p4byr3.gif)

$3


#### Default
##### .$path
@m-abboud
Also, you can get access to the path string using $path special field.

Like this:
`js
console.log(tp().a.b.c.d.$path); // this will output "a.b.c.d"
`

##### .$raw
@dcbrwn
If you need a raw path, which is of type string[] - you can get it using $raw special field.
*Deprecated, since it transforms symbols and numbers to strings, which might be not an expected behavior (the method name is "raw").
Please use .$rawPath*
`js
console.log(tp().a.b.c.d.$raw); // this will output ["a", "b", "c", "d"]
`

##### .$rawPath
If you need a raw path, which is of type (string | number | Symbol)[] - you can get it using $rawPath special field.
`js
console.log(tp().a.b[5].c.d.$rawPath); // this will output ["a", "b", 5, "c", "d"]
`

The $rawPath is something that you might want to use with the following methods from
Ramda, to add type safety on the path:
- R.assocPath,
- R.dissocPath,
- R.hasPath,
- R.path,
- R.pathEq,
- R.pathOr,
- R.paths,
- R.lensPath

Example: https://codesandbox.io/s/typed-path-ramda-assoc-path-x3qby?file=/src/index.ts

#### Additional handlers
@nick-lvov-dev

You can extend path handlers functionality using additional handlers:

`js
const testAdditionalHandlers = {
$url: (path: TypedPathKey[]) => path.join('/')
}

console.log(tp(testAdditionalHandlers).a.b.c.$url); // this will output "a/b/c"
`

The additional handlers are also chainable:

`js
const testAdditionalHandlers = {
$abs: (path: TypedPathKey[]) => typedPath(testAdditionalHandlers, ['', ...path]),
$url: (path: TypedPathKey[]) => path.join('/'),
$length: (path: TypedPathKey[]) => path.length
}

console.log(tp(testAdditionalHandlers).a.b.c.$abs.$url); // this will output "/a/b/c"
`

---

$3

Also, typed-path` allows typescript to suggest field names for you.


License

Copyright (c) 2021 Oleksandr Beshchuk <bs.alex.mail@gmail.com>
Licensed under the Apache License.