@alanscodelog/utils
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    Function walk

    • Recursively walks through an object or array (and also technically null too if you force it).

      walk(obj, (val, keypathArr) => { ... })

      Save can used to save the return of the callback (if no callback is given it just returns the value), and deep clone objects.

      const deepClone = walk(obj, undefined, {save:true})

      As well as more complicated operations that can preserve certain keys (such as in the case of Error instances or other such objects.)

      const seen = {}

      walk(obj, (val, keypath, stage) => {
      	if (stage === "before") {
      		const key = keypath.join(".")]
      		if (val instanceof ObjectWeWantToPreserve) { // e.g. Error
      			seen[key] = val
      				// return dummy empty value to avoid looping over the value
      			// note this needs to return []/{}/null
      			return {}
      		}
      	}
      	if (stage === "after")
      		if (seen[key]) {
      			return seen[key]
      		}
      	}
      )
      }, {before: true, after: true, save: true})

      In the above scenerio, if not using save and we just want to modify the object directly, we could do {before:true} and use a Map<keypathAsString, val> to keep a list of keys to modify. Then after (to avoid interfering with the walk) we loop through those keys in reverse (to get deepest keys first, to avoid conflicts) then mutate those keypaths using {@link set}.

      Type Parameters

      • TSave extends boolean = false
      • TRes extends any = TSave extends true ? any : undefined

      Parameters

      • obj: any
      • Optionalwalker: (el: any, keyPath: string[], stage?: "before" | "after") => any
      • opts: { after?: boolean; before?: boolean; save?: TSave } = {}
        • Optionalafter?: boolean

          If true, run walker on the value after attempting to loop through it's keys. If save is true, this can be used to modify the final value.

        • Optionalbefore?: boolean

          If true, run walker on the value before attempting to loop through it's keys. If save is true, this can be used to modify the object that will be looped over.

        • Optionalsave?: TSave

          If true, will "save" the result of the walker, allowing it to be used for deep map/cloning of objects. By "save" we mean, the return value of the walker will be assigned to the property (if it does not return undefined) and walk will return the modified clone. Using save will change the return type to any since otherwise it is impossible to type. You can use the second type parameter to set it manually.

      Returns TRes

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