@smartlyio/safe-navigation
v5.1.1
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typescript and null safe json object navigation
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safe-navigation
type(script) and null safe navigation in json objects
get .$
Returns the value or undefined if any value on the path to it is undefined
// yarn ts-node examples/getter.ts
import safe from '../index';
import * as assert from 'assert';
interface A {
a?: { b?: string };
}
const o: A = { a: { b: 'x' } };
assert(safe(o).a.b.$ === 'x');
The optional chaining also takes into account union types.
// yarn ts-node examples/unions.ts
import safe from '../index';
import * as assert from 'assert';
type A = { a: number } | { b: string };
const o: A = { a: 1 };
assert(safe(o).a.$ === 1);
set value .$set
Returns a new object with the target set to value if the path to value exists
// yarn ts-node examples/set.ts
import safe from '../index';
import * as assert from 'assert';
interface A {
a?: { b?: string };
}
const o: A = { a: { b: 'old' } };
const newValue: A = safe(o).a.b.$set('new');
assert(safe(newValue).a.b.$ === 'new');
map value .$map
Maps the value at end of the path
// yarn ts-node examples/map.ts
import safe from '../index';
import * as assert from 'assert';
interface A {
a?: { b?: string };
}
const o: A = { a: { b: 'old' } };
const newValue: A = safe(o).a.b.$map((n: any) => n + ' to new');
assert(safe(newValue).a.b.$ === 'old to new');
map with promises .$pmap
Returns a new object with the target mapped using a promise returning map function
// yarn ts-node examples/pmap.ts
import safe from '../index';
import * as assert from 'assert';
interface A {
a?: { b?: string };
}
// eslint-disable-next-line @typescript-eslint/no-floating-promises
(async function () {
const o: A = { a: { b: 'x' } };
const result = await safe(o).a.b.$pmap(async value => 'got ' + value);
assert(safe(o).a.b.$ === 'x');
assert(safe(result).a.b.$ === 'got x');
})();