inspect: print individual AggregateError.errors

[LiviaMedeiros]

What is the problem this feature will solve?

> (() => {
throw new AggregateError([
  new TypeError('blep'),
  new RangeError('blop')
], 'gwak');
})();
Uncaught AggregateError: gwak
    at REPL6:2:7

When AggregateError is uncaught or inspected by util.inspect(), its errors property is ignored, so all individual errors are being swallowed. We can't get information about what exactly happened, where it happened, even how many errors there were.

What is the feature you are proposing to solve the problem?

Printing all .errors with their respective stacktraces, either adding it to AggregateError info or replacing it.

What alternatives have you considered?

Abbreviated output, something like AggregateError[ TypeError, TypeError, EvalError ]. This still doesn't provide enough info: each aggregated error is an uncaught exception/rejection, and debug info should provide as much details as possible about them.

[SimenB]

Would it be possible to make this nested/recurse?

(()=>{throw new AggregateError([new AggregateError([new TypeError('blep'), new RangeError('blop')], 'inner')],'gwak')})()
Uncaught AggregateError: gwak
    at REPL2:1:13 {
  [errors]: [
    AggregateError: inner
        at REPL2:1:33
        at REPL2:1:120
        at Script.runInThisContext (node:vm:129:12)
        at REPLServer.defaultEval (node:repl:572:29)
        at bound (node:domain:433:15)
        at REPLServer.runBound [as eval] (node:domain:444:12)
        at REPLServer.onLine (node:repl:902:10)
        at REPLServer.emit (node:events:525:35)
        at REPLServer.emit (node:domain:489:12)
        at REPLServer.Interface._onLine (node:readline:491:10) {
      [errors]: [Array]
    }
  ]
}

Notice [errors]: [Array]

[LiviaMedeiros]

This is recursive, but the depth is limited by default.

> [[[123]]]
[ [ [ 123 ] ] ]

> [[[[123]]]]
[ [ [ [Array] ] ] ]

Inspecting explicitly:

> try {
(()=>{throw new AggregateError([new AggregateError([new TypeError('blep'), new RangeError('blop')], 'inner')],'gwak')})()
} catch(e) { console.log(util.inspect(e)) }

AggregateError: gwak
    at REPL34:1:19
    at REPL34:1:126
    at Script.runInThisContext (node:vm:129:12)
    at REPLServer.defaultEval (node:repl:572:29)
    at bound (node:domain:433:15)
    at REPLServer.runBound [as eval] (node:domain:444:12)
    at REPLServer.onLine (node:repl:902:10)
    at REPLServer.emit (node:events:525:35)
    at REPLServer.emit (node:domain:489:12)
    at [_onLine] [as _onLine] (node:internal/readline/interface:425:12) {
  [errors]: [
    AggregateError: inner
        at REPL34:1:39
        at REPL34:1:126
        at Script.runInThisContext (node:vm:129:12)
        at REPLServer.defaultEval (node:repl:572:29)
        at bound (node:domain:433:15)
        at REPLServer.runBound [as eval] (node:domain:444:12)
        at REPLServer.onLine (node:repl:902:10)
        at REPLServer.emit (node:events:525:35)
        at REPLServer.emit (node:domain:489:12)
        at [_onLine] [as _onLine] (node:internal/readline/interface:425:12) {
      [errors]: [Array]
    }
  ]
}

Inspecting with depth: 9:

> try {
(()=>{throw new AggregateError([new AggregateError([new TypeError('blep'), new RangeError('blop')], 'inner')],'gwak')})()
} catch(e) { console.log(util.inspect(e, { depth: 9 })) }

AggregateError: gwak
    at REPL37:1:19
    at REPL37:1:126
    at Script.runInThisContext (node:vm:129:12)
    at REPLServer.defaultEval (node:repl:572:29)
    at bound (node:domain:433:15)
    at REPLServer.runBound [as eval] (node:domain:444:12)
    at REPLServer.onLine (node:repl:902:10)
    at REPLServer.emit (node:events:525:35)
    at REPLServer.emit (node:domain:489:12)
    at [_onLine] [as _onLine] (node:internal/readline/interface:425:12) {
  [errors]: [
    AggregateError: inner
        at REPL37:1:39
        at REPL37:1:126
        at Script.runInThisContext (node:vm:129:12)
        at REPLServer.defaultEval (node:repl:572:29)
        at bound (node:domain:433:15)
        at REPLServer.runBound [as eval] (node:domain:444:12)
        at REPLServer.onLine (node:repl:902:10)
        at REPLServer.emit (node:events:525:35)
        at REPLServer.emit (node:domain:489:12)
        at [_onLine] [as _onLine] (node:internal/readline/interface:425:12) {
      [errors]: [
        TypeError: blep
            at REPL37:1:59
            at REPL37:1:126
            at Script.runInThisContext (node:vm:129:12)
            at REPLServer.defaultEval (node:repl:572:29)
            at bound (node:domain:433:15)
            at REPLServer.runBound [as eval] (node:domain:444:12)
            at REPLServer.onLine (node:repl:902:10)
            at REPLServer.emit (node:events:525:35)
            at REPLServer.emit (node:domain:489:12)
            at [_onLine] [as _onLine] (node:internal/readline/interface:425:12),
        RangeError: blop
            at REPL37:1:82
            at REPL37:1:126
            at Script.runInThisContext (node:vm:129:12)
            at REPLServer.defaultEval (node:repl:572:29)
            at bound (node:domain:433:15)
            at REPLServer.runBound [as eval] (node:domain:444:12)
            at REPLServer.onLine (node:repl:902:10)
            at REPLServer.emit (node:events:525:35)
            at REPLServer.emit (node:domain:489:12)
            at [_onLine] [as _onLine] (node:internal/readline/interface:425:12)
      ]
    }
  ]
}

[SimenB]

Right, my point was more if it could work by default for console.log etc without the depth argument?