Add error description to BleakDBusError in addition to error name

[bojanpotocnik]

Converting BleakDBusError to string now adds detailed description of the
error, which can be very useful for debugging, as more than 12 different
errors are reported under org.bluez.Error.Failed error name.

Instead of

bleak.exc.BleakDBusError: org.bluez.Error.Failed

one now gets

bleak.exc.BleakDBusError: org.bluez.Error.Failed (Operation failed with ATT error: 0x0e = Connection Rejected Due To Security Reasons)

Some details are less useful, as example

bleak.exc.BleakDBusError: org.bluez.Error.AuthenticationFailed

becomes

bleak.exc.BleakDBusError: org.bluez.Error.AuthenticationFailed (Authentication Failed)

But looking at more possible error codes and their details (majority
from BlueZ sources gdbus/object.c and src/gatt-client.c), it becomes
clear that additional description of error can be very useful:

  org.freedesktop.DBus.Error.InvalidArgs
  org.freedesktop.DBus.Error.UnknownProperty

    No such interface '%s'
    No such property '%s'
    Invalid signature for '%s'
    Invalid argument type: '%c'
    Property '%s' is not readable
    Property '%s' is not writable
    No arguments given

  org.bluez.Error.Failed

    `strerror(-err)`
    Connect failed
    Not connected
    Invalid UUID
    Operation failed with ATT error: 0x%02x
    Failed to initiate write
    ... and many more

[dlech]

This is cool. I didn't know that D-Bus included extra info like this.

To keep things simple and to make sure we don't miss anything useful, I wouldn't mind always including the extra info even if it is redundant in some cases.

[dlech]

Thinking about this a bit more, it occurred to me that it might be nice to format this similar to OSError where the machine readable part is in square braces, i.e. f"[{args[0]}] {args[1]}" which would become bleak.exc.BleakDBusError: [org.bluez.Error.Failed] Operation failed with ATT error: 0x0e = Connection Rejected Due To Security Reasons. Thoughts?

[bojanpotocnik]

Good idea.

bleak.exc.BleakDBusError: [org.bluez.Error.AuthenticationFailed] Authentication Failed
bleak.exc.BleakDBusError: [org.bluez.Error.Failed] Operation failed with ATT error: 0x0e (Connection Rejected Due To Security Reasons)

But what about when there is no detail?

bleak.exc.BleakDBusError: [org.bluez.Error.AuthenticationFailed]

or

bleak.exc.BleakDBusError: org.bluez.Error.AuthenticationFailed

🤔 I guess if we are talking about machine readability, consistency shall have priority, so the first one?

[dlech]

consistency shall have priority, so the first one?

I agree with that.

[bojanpotocnik]

Done, the format is now

bleak.exc.BleakDBusError: [name] Details (further parsed details)
bleak.exc.BleakDBusError: [org.bluez.Error.Failed]
bleak.exc.BleakDBusError: [org.bluez.Error.Failed] Authentication Failed
bleak.exc.BleakDBusError: [org.bluez.Error.Failed] Operation failed with ATT error: 0x0e (Connection Rejected Due To Security Reasons)

[dlech]

Thanks for your work on this!