Option to output JSON

[brandonchinn178]

It would be great to have a --json or --format json flag to force all output to be json lines

Use-case: we're running goose in a service, and we expect any output from our service to be JSON. We could parse the output + reoutput as JSON or just collect all output and output as a single string, but it'd be nicer to have that output out of the box

Related: #225

[mfridman]

Ye I'd like to see this as well. Should be a fairly straightforward add, just need to define the returned structs.

I might give this a go in the next few days.

[mfridman]

I might give this a go in the next few days year 😅 .

The plan is to make JSON output, for all commands, natively supported in #379.

One thing I'm currently thinking through is the user experience when relying on --json, what should the unhappy path be when there is a partial migration error running goose up (as an example).

happy path:

{
  "migrations": [
    {
      "migration_type": "sql",
      "version": 1,
      "filename": "00001_add_table.sql",
      "duration_ms": 17,
      "direction": "up",
      "empty": false
    },
    {
      "migration_type": "sql",
      "version": 2,
      "filename": "00002_fill_lots_of_data.sql",
      "duration_ms": 889,
      "direction": "up",
      "empty": false
    },
    {
      "migration_type": "sql",
      "version": 3,
      "filename": "00003_create_concurrent_index.sql",
      "duration_ms": 1153,
      "direction": "up",
      "empty": false
    }
  ],
  "total_duration_ms": 2090,
  "message": "successfully ran 3 migrations in 2.09s"
}

unhappy path:

In this particular case, we have 2 valid migrations files and 1 invalid migration file. Running goose up --json will apply the first two, but fail on the third one.

The best we can do (if the goal is to retain JSON output) is to surface a new error field.

{
  "migrations": [
    {
      "migration_type": "sql",
      "version": 1,
      "filename": "00001_add_table.sql",
      "duration_ms": 9,
      "direction": "up",
      "empty": false
    },
    {
      "migration_type": "sql",
      "version": 2,
      "filename": "00002_fill_lots_of_data.sql",
      "duration_ms": 947,
      "direction": "up",
      "empty": false
    },
    {
      "migration_type": "sql",
      "version": 3,
      "filename": "00003_create_concurrent_index.sql",
      "duration_ms": 1,
      "direction": "up",
      "empty": false,
      "error": "ERROR: CREATE INDEX CONCURRENTLY cannot run inside a transaction block (SQLSTATE 25001)"
    }
  ],
  "total_duration_ms": 987,
  "message": "partial migration error: ERROR: CREATE INDEX CONCURRENTLY cannot run inside a transaction block (SQLSTATE 25001)"
}

[MicrowaveTank]

Has there been any recent movement on this? Goose is a nice migration tool and I'm working on writing a Java wrapper for its CLI. The stdout isn't too hard to parse, but JSON output would make the parsing feel significantly less brittle.