Preserve whitespace in text nodes

[cwhitehouse]

Description

Pass the text from a text node directly to the JSON created via to_h instead of stripping out whitespace only strings.

Reason/Reference

Text nodes that just contain whitespace have a valid use case, such as separating out two text nodes with marks. This currently prevents you from having a space between two link nodes, for example.

Example

The message...

I would like a banana milkshake

Should have four JSON text nodes that look like...

...
{ type: "text", text: "I would like a " },
{ type: "text", text: "banana", marks: [LINK MARKS] },
{ type: "text", text: " " },
{ type: "text", text: "milkshake", marks: [LINK MARKS] }
...

...but the current implementation returns...

...
{ type: "text", text: "I would like a " },
{ type: "text", text: "banana", marks: [LINK MARKS] },
{ type: "text", text: "" },
{ type: "text", text: "milkshake", marks: [LINK MARKS] }
...

... which would mean if we pass the JSON to an editor we would get:

I would like a bananamilkshake

... instead of what we expected.

[chadwilken]

IIRC I did the presence || "" bit because text was nil sometimes and TipTap JS wouldn't render the document stating that text can't be null. It turns out that text can't be an empty string either so my fix didn't actually work. I'm actually surprised that this is removing your " " string since that isn't empty?.

[chadwilken]

Ah but it is blank? I guess so that is why it's falling back to this. I think your fix should be fine.

[cwhitehouse]

We could also do text || "" to split the difference — though I guess it doesn't matter if empty strings are also problematic — but yeah presence is being too aggressive here

[chadwilken]

Yea that's a nice middle ground I think.

[chadwilken]

@cwhitehouse can you fix the standard lint errors?