Class Inheritance Reporter

[jayqi]

Closes #14

Summary:

• New InheritanceReporter that extracts the inheritance network for S4, Reference, and R6 classes within a given package.
  • Per discussion in Revisiting the directionality of edges (Nov 2018) #131, edge direction points from Child to Parent.
• Changed FunctionReporter to explicitly exclude generator functions for Reference classes for now.
  I'm not sure the best way to represent object construction in FunctionReporter yet.
• Added some S4 and Reference classes to milne for testing.
• Changed all pallete to correct spelling palette.

Viz for pkgnet:

Viz for milne

[bburns632]

@jayqi , I am excited to see results from these two tests:

devtools::install('.')

devtools::install("./inst/milne")
t3 <- InheritanceReporter$new()
t3$set_package(pkg_name = 'milne')
t3$edges
t3$graph_viz 

t4 <- InheritanceReporter$new()
t4$set_package(pkg_name = 'lubridate')
t4$edges
t4$graph_viz 

Here's the lubridate graph.

However, I cannot reference this as a reporter through our high level function CreatePackageReport().

pkgnet::CreatePackageReport('lubridate', pkg_reporters = c(DefaultReporters, InheritanceReporter)) # error
pkgnet::CreatePackageReport('milne', pkg_reporters = c(DefaultReporters, InheritanceReporter)) # error

In both cases, I get the error "At least one of the reporters in the pkg_reporters parameter is not a PackageReporter. See ?AbstractPackageReporter for details." stemming from this test: https://github.com/UptakeOpenSource/pkgnet/blob/master/R/CreatePackageReport.R#L37

Can we enable this reporter to be used in this fashion (a specific call out in CreatePackageReport) before we merge this PR? Then, in a later R, we could automate this with an R6::is.R6() check.

[jayqi]

@bburns632 Ironically, you are getting the errors because you are using both CreatePackageReport and DefaultReporters incorrectly. (Relevant to the discussion of getting rid of set_package in #106.)

The following works for me:

pkgnet::CreatePackageReport('lubridate'
                            , pkg_reporters = c(DefaultReporters()
                                                , InheritanceReporter$new()
                                                ))
pkgnet::CreatePackageReport('milne'
                            , pkg_reporters = c(DefaultReporters()
                                                , InheritanceReporter$new()
                                                ))

The key two things are:

• DefaultReporters is a function and not directly a list of reporters
• Inputs to CreatePackageReport must be initialized reporter objects, not the generators

cc: @jameslamb

[jameslamb]

Looks great, Jay! I added some suggestions for changed. @ me when you want me to review again.

Overall I agreed with the approach and the core of the implementation. My recommendations are mostly about hardening it a bit to avoid subtle errors or pedantic stuff like whitespace.

[jayqi]

@jameslamb I think I have resolved all of your comments.

[jameslamb]

LGTM

[bburns632]

Yes, the irony is delicious here. Clearly, this is not an issue with this reporter, but a UX issue to bring up later regarding using speciality or custom reporters (now that we have a new one!).

All changes look good to me.