merge.all with single element array

[shawn98ag]

I'm curious why when one calls merge.all() with a single element array, [{'a':1}], this function doesnt just return the value of that first element in the array {'a':1}? The function is instead throwing an error.

In my code, I'm dynamically creating an array of objects that I need to merge together. Occasionally, that array only has one element. To protect against this error I have to add .concat({}) to the array argument increase its length to 2.

[TehShrike]

deepmerge doesn't mutate either argument that is passed in to it, so it's difficult to imagine what would happen if you passed just a single object to it. Would it just be a shallow copy to a new object, like Object.assign?

It would be a breaking change, but I think it would be a bit easier to fix this if we made clone default to true so that there would always be some default behavior you could expect ("copy everything").

As an aside, I'd personally prefer this to the concat I think:

const output = array.length > 1 ? merge.all(array) : array[0]

Or if you want the copy:

const output = array.length > 1 ? merge.all(array) : merge({}, array[0])

[TehShrike]

My current stance: if we do publish a breaking change to make cloning the default (#72), we can feel free to make this change so that merge.all can take any number of inputs.

[TehShrike]

As of version 2.0.0, merge.all takes an array of any size, including 0.