implement test-hjust-text-anchor.R

[caijun]

Using test-hjust-text-anchor.R to test Animint, the testing results are as follows

1. Failure(@test-hjust-text-anchor.R#96): geom_text(hjust=0) => ----------------
   style.value does not match 'start'. Actual value: "middle"
2. Failure(@test-hjust-text-anchor.R#103): geom_text(hjust=1) => -----------------
   style.value does not match 'end'. Actual value: "middle"

[tdhock]

in tests it is best to be as explicit as possible, so I would recommend that grad.desc.viz returns an animint list of ggplots and options, and then you take animint2HTML outside of the grad.desc.viz function, e.g.

viz <- grad.desc.viz(hjust=0)
info <- animint2HTML(viz)

[caijun]

I have implemented get_text_anchor function in animint.js.

https://github.com/caijun/animint/blob/master/inst/htmljs/animint.js#L717-L733

Tests of geom_text(hjust=0) => <text style="text-anchor: start">, geom_text(hjust=1) => <text style="text-anchor: end">, and geom_text(hjust=0.5) => <text style="text-anchor: middle"> tests in test_hjust_text_anchor.R have successfully been passed.

Yes, it's easier to understand the code if putting animint2HTML outside of the grad.desc.viz function. I have updated test-hjust-text-anchor.R.

As for the geom_text(hjust=0.5) => <text style="text-anchor: middle"> test, in my grad.desc.viz, hjust aesthetic is given by a variable name rather than a value.

geom_text(aes(hjust = hjust)

The invalid input of hjust should be checked in get_text_anchor function and give a warning. But I don't know how pass warning from Javascript to R.

[tdhock]

These changes look good. Although it is possible to check for invalid hjust values at rendering time (and maybe report it using console.log), I think it makes more sense to check at compile time and then assume we have valid values at rendering time.

Actually there is already R code that should stop the compiler with an error

https://github.com/tdhock/animint/blob/master/R/animint.R#L174-L188

so please change the test to check for an error (not a warning), as we do with hjust for axis labels

https://github.com/tdhock/animint/blob/master/tests/testthat/test-rotate.R#L90-L97

[caijun]

I check for invalid hjust values inside the saveLayer function of animint compiler.

https://github.com/caijun/animint/blob/master/R/animint.R#L322-L330

The test for invalid hjust values has been changed to check for an error.

https://github.com/caijun/animint/blob/master/tests/testthat/test-hjust-text-anchor.R#L114

All tests of test-hjust-text-anchor.R have been successfully passed, and you can merge this branch.

[tdhock]

Looks good to me. Now just update the package version to 2015.03.23 in DESCRIPTION, and add some info about the bug that you fixed in NEWS. After that I will merge into master.