Create blob backed up by filesystem

[jimmywarting]

haven't been any discussion about how to go about solving this so i have made a first attempt/design at creating a blob backed up by filesystem.

Think this could be useful for ppl who need to to work with FormData for example

const blobFrom = require('fetch-blob/from.js')
const fd = new FormData()
const blob = blobFrom('./wallpaper.png')
fd.append('portrait', blob, 'wallpaper.png')

This don't add to the bundle size unless you implicit import/require "fetch-blob/from.js"

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i first thought about doing something like blob = Blob.from(path) but that would make it different from the spec and adds to the bundle cost

[codecov]

Codecov Report

Merging #55 into master will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master       #55   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         2    +1     
  Lines          176       231   +55     
  Branches        32        36    +4     
=========================================
+ Hits           176       231   +55     

Impacted Files	Coverage Δ
from.js	100.00% <100.00%> (ø)

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[Richienb]

Shouldn't from.js be included in the files array in package.json?

[jimmywarting]

have added from.js to files array now

can't find anything else that needs to be done

[jimmywarting]

just tried it out as a real developer

tried to install it: works ok
tried using it: works ok

like it better then native fs 🙂

import blobFrom from 'fetch-blob/from.js' 

const text = await blobFrom('package.json').text()
const arrayBuffer = await blobFrom('package.json').text()
const stream = blobFrom('package.json').stream()
const chunk = await blobFrom('package.json').slice(5, 10).text()