ipfs --encoding=json ls not returning JSON

[dokterbob]

Version information:

go-ipfs version: 0.4.23-6ce9a35
Repo version: 7
System version: amd64/darwin
Golang version: go1.13.7

Description:

The output of ipfs --encoding=json ls is expected to return JSON, as with other commands. Instead, the output is the same as without the encoding parameter.

Example:

$ ipfs ls /ipfs/QmQy8FTQCdJGtNHg92pc4B6F4cjnuSdrFx9gdRmkrE1rVF
QmWyDJmrr6cRwEpTF2VGhWDi4uytrDHT8S5BptVdkbhjpv 6060 README.md

$ ipfs --encoding=json ls /ipfs/QmQy8FTQCdJGtNHg92pc4B6F4cjnuSdrFx9gdRmkrE1rVF
QmWyDJmrr6cRwEpTF2VGhWDi4uytrDHT8S5BptVdkbhjpv 6060 README.md

Expected output similar to HTTP API call:

curl "http://localhost:5001/api/v0/ls?arg=/ipfs/QmQy8FTQCdJGtNHg92pc4B6F4cjnuSdrFx9gdRmkrE1rVF" | jq
{
  "Objects": [
    {
      "Hash": "/ipfs/QmQy8FTQCdJGtNHg92pc4B6F4cjnuSdrFx9gdRmkrE1rVF",
      "Links": [
        {
          "Name": "README.md",
          "Hash": "QmWyDJmrr6cRwEpTF2VGhWDi4uytrDHT8S5BptVdkbhjpv",
          "Size": 6060,
          "Type": 2,
          "Target": ""
        }
      ]
    }
  ]
}

[hsanjuan]

Linking to a similar one #5594. I wonder if this an easy fix or there is more to it though.

[Stebalien]

I believe the solution is to detect that (a) the output is text and (b) the target is a terminal in PostRun. Then, just forward results instead of rendering them.

[Stebalien]

Even better, introduce a Terminal PostRun type and only run it under those conditions.

[hsanjuan]

But @Stebalien , why do we have to detect anything, if I'm explicitally asking for --enc=json, shouldn't it just use the json encoder with that option?

It sounds like it should still use text when the target is not a terminal, but it should use whatever the --enc= flag says.

[Stebalien]

The problem is that we're abusing PostRun. It's designed to post-process results on the client (read results from the response, re-emit them to the next response emitter). Take a look at the ping command.

However, we're using it to write to the console. We should be using the text encoder but:

1. The text encoder is invoked once per event. This makes it hard to initialize/finalize the output.
2. The text encoder will be run on the server if the user makes a curl request. That's usually not what we want.

That's why I'm saying we should consider having some kind of Terminal post-run command. Or maybe a new encoder? Or even an entirely new Display function ipfs/go-ipfs-cmds#115?