React-native-fetch-blob: base64() doese not work

[gonglong]

I want to download an image and convert its content into base64 string.

Here is what I did:

RNFetchBlob
.config({
fileCache : false,
appendExt : imageExtension,
})
.fetch('GET', this.props.imageUrl, {
//some headers ..
})
.then((res) => {
// here the data would be something like {-10: '', -25: null}
const data = res.base64();
})

curiously, sometime later, the data would be changed into something like {-10: '"", -25: "quite long base64 string"}. I guess something done in native thread and changed the data. Anyway , i cannot get the base64 string. Is there anything I am wrong ?

iOS11
RN 0.48

Thanks

[gonglong]

I changed the way and it works as expect. But it would be better if base64() works

let imagePath = null;
RNFetchBlob
.config({
fileCache : true,
appendExt : imageExtension,
})
.fetch('GET', this.props.imageUrl, {
//some headers ..
})
.then((res) => {
imagePath = res.path();
// changes to use readFile
return res.readFile('base64');
}).then((base64ImageData)=>{
// I can use the base64 data now
// just for removing template file in case
return RNFetchBlob.fs.unlink(imagePath);
})

[rochapablo]

I tried, but I'm getting

[Error: RNFetchBlob request error: url == nullnull]

[romreed]

same error