[WIP] Catch and display path errors

[kbrock]

Depends upon

• Choice rule payload validation #189

2.5 things:

• If a user specifies a bad path in a workflow, display a meaningful message.
• If a user specifies a path that fails a lookup in runtime, display a meaningful message.
• (This is not working with templates - not worse, but not informative/better either)

Invalid path (validation)

    "Test1": {
      "Comment": "Parameter not a path",
      "Type":  "Pass",
      "InputPath": "nonparam",
      "End": true
    }

aws:

Field "InputPath" defined at "State Machine.Test1" is not a JSONPath

Before

Path [nonparam] must start with "$"

After

States.Test1 field "InputPath" value "nonparam" Path [nonparam] must start with "$"

Path not found (runtime)

    "Test2": {
      "Type":  "Pass",
      "InputPath": "$.missing"
      "End": true
    }

aws:

Invalid path '$.missing' : No results for path: $['missing']

Before

{}

After

{
  "Error":"States.RuntimeError",
  "Cause":"States.Test2 field \"InputPath\" value \"$.missing\" references an invalid value"
}

[kbrock]

update:

• rubocop changes

update:

• removed some changes to process_output (code climate changes)

[Fryguy]

This feels like adding a lot of "code" to just present error messages. Is it possible to just not have the wrap_runtime_error as that feels like the method that is adding a lot of this overhead?

I am curious why the PathError itself can't contain the details within, since it is being raised from within the Path itself. Additionally, is every instance of PathError just also an ExecutionError? If so, could it just raise an ExecutionError instead, or, if not, can PathError just be a subclass of ExecutionError?

[kbrock]

@Fryguy The problem is a generically thrown exception will not properly have the context for the error. So either the thing throwing the error needs more information, or we need to add information on the way up.

I'll add the state/path to the Path, so it can throw a better exception.

[Fryguy]

I'm not sure I follow... It looks like the same thing is passed into path that's wrapped outside of it as well

[kbrock]

WIP: I care more about Choice fixes than error display. incorporating these errors on top of #189

[Fryguy]

As Adam asked elsewhere, is States.RuntimeError an actual error?

[agrare]

#189 (review) it isn't listed in the states-language spec but it is in the AWS StepFunctions docs and he fixed it to be States.Runtime to match the docs there

[kbrock]

update:

• rebased onto latest choice payload validation

[miq-bot]

Checked commits kbrock/floe@825efcb~...8c0ee6c with ruby 3.1.5, rubocop 1.56.3, haml-lint 0.51.0, and yamllint
20 files checked, 0 offenses detected
Everything looks fine. 🍰

[miq-bot]

This pull request is not mergeable. Please rebase and repush.

[kbrock]

WIP: keeping up to date locally. waiting for choice to go through before putting too much effort into this. (they all conflict)

Also, my push more information into Path so it throws the fully qualified error instead of partial and having to manipulate the exception on the way up

[miq-bot]

This pull request has been automatically marked as stale because it has not been updated for at least 3 months.

If these changes are still valid, please remove the stale label, make any changes requested by reviewers (if any), and ensure that this issue is being looked at by the assigned/reviewer(s).

[miq-bot]

This pull request has been automatically marked as stale because it has not been updated for at least 3 months.

If these changes are still valid, please remove the stale label, make any changes requested by reviewers (if any), and ensure that this issue is being looked at by the assigned/reviewer(s).

[miq-bot]

This pull request has been automatically marked as stale because it has not been updated for at least 3 months.

If these changes are still valid, please remove the stale label, make any changes requested by reviewers (if any), and ensure that this issue is being looked at by the assigned/reviewer(s).

[kbrock]

WIP: TODO: pull out JSON parsing first. Then focus on path errors. Still unsure about giving path more information so the error is more understandable

[Fryguy]

Suggested change

	value = wrap_runtime_error(field_name, field_path.to_s) { field_path.value(context, input) }
	value = wrap_runtime_error(field_name, field_path.to_s) { field_path.value(context, input) }

[kbrock]

update:

• rebased
• fixed rubocop

WIP: still WIP as I'd like to move JSON.parse out of the initializers before handling the path errors - though can't remember right now why I felt that needed to be done first