Convert Bytes returned by a View into a frontend string without padding

[lorenzopolidori]

I think my problem might have a simple answer, but I can't find it after some attempts.

I have this simple Reach programme:

export const main = Reach.App(() => {
    const A = Participant('Admin', {
        ...hasConsoleLogger,
        onReady: Fun(true, Null),
        name: Bytes(128),
        url: Bytes(128),
        hash: Bytes(32)
    })

    const ProjectView = View('View', {
        name: Bytes(128),
        url: Bytes(128),
        hash: Bytes(32)
    })

    const Api = API('Api', {
        updateName: Fun([Bytes(128)], Null),
        updateMetadata: Fun([Bytes(128), Bytes(32)], Null),
        stop: Fun([], Bool)
    })

    init()

    A.only(() => {
        const [projectName, metadataUrl, metadataHash] = declassify([interact.name, interact.url, interact.hash])
    })

    A.publish(projectName, metadataUrl, metadataHash)

    A.interact.onReady(getContract())
    A.interact.log('The project contract is ready')

    const [done, name, url, hash] = parallelReduce([false, projectName, metadataUrl, metadataHash])
        .define(() => {
            ProjectView.name.set(name)
            ProjectView.url.set(url)
            ProjectView.hash.set(hash)
        })
        .invariant(balance() == 0)
        .while(!done)
        /**
         * Update project name
         */
        .api(Api.updateName, (newName, k) => {
            k(null)
            return [false, newName, url, hash]
        })
        /**
         * Update project metadata
         */
        .api(Api.updateMetadata, (newUrl, newHash, k) => {
            k(null)
            return [false, name, newUrl, newHash]
        })
        /**
         * Stops this contract
         */
        .api(
            Api.stop,
            () => {
                assume(this == A)
            },
            () => 0,
            k => {
                const isAdmin = this == A
                require(isAdmin)
                k(isAdmin)
                return [true, name, url, hash]
            }
        )
        .timeout(false)

    commit()
    A.interact.log('The project contract is closing down...')
    exit()
})

In my frontend test, I set name, url and hash as strings, e.g. const name = 'project 1'.

However, when I call the view after successful deployment:

const ctc = account.contract(backend, contract.getInfo())
const view = ctc.v.View
const name = await view.name()[1]

name is returned as a string padded with \x00 to the specified size:

'project 1\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'

Is there a Reach stdlib utility function to easily convert that string into a shorter one, without the padding?

[jeapostrophe]

There is no such utility function; just use normal JS

[lorenzopolidori]

That's fine, I can do that. As a suggestion, could we have a stdlib.bytesToString() function do make the conversion transparent for the frontend?

[jeapostrophe]

We actually planning to change Bytes itself by making it ALWAYS return Uint8Array and then introduce a new String that will automatically remove the NUL bytes.