Add TCJA preset

[hdoupe]

This PR adds the TCJA preset. Due to the number of parameters involved in creating this preset, I went through considerable lengths to make sure I put everything together correctly. I included the preset creation and testing scripts so that others can check my work.

1. I manually translated the TCJA_Reconciliation.json file to a dictionary that can be programmatically posted to TaxBrain. I programmatically posted this file to the test app. I then compared the results from this method with the results from uploading TCJA_Reconciliation.json via the file input interface.
2. I used TaxBrain GUI input parsing functions to convert this dictionary to a Tax-Calculator styled dictionary and the TCJA_Reconciliation.json file into a Tax-Calculator styled dictionary. I then compared parameters and parameter values to make sure that the file and the dictionary are equivalent.

You can check the file post here: http://ospc-taxes7.herokuapp.com/taxbrain/1507/
You can check the programmatic post here: http://ospc-taxes7.herokuapp.com/taxbrain/1510/
[EDIT] Production post is here: https://www.ospc.org/taxbrain/edit/30126/?start_year=2018

[hdoupe]

PR #792 passes with changes from #790. See:

(aei_dropq) HDoupe-MacBook-Pro:PolicyBrain henrydoupe$ git pull origin reverse_character
From https://github.com/hdoupe/PolicyBrain
 * branch            reverse_character -> FETCH_HEAD
Auto-merging templates/taxbrain/input_form.html
Merge made by the 'recursive' strategy.
 templates/taxbrain/input_form.html         |  1 +
 webapp/apps/taxbrain/forms.py              |  5 +++--
 webapp/apps/taxbrain/helpers.py            | 36 +++++++++++++++++++++++++++++++++---
 webapp/apps/taxbrain/models.py             |  2 +-
 webapp/apps/taxbrain/tests/test_helpers.py | 15 ++++++++++++---
 webapp/apps/taxbrain/tests/test_views.py   | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 webapp/apps/taxbrain/views.py              |  3 ++-
 webapp/apps/test_assets/test_reform.py     | 11 ++++++++---
 8 files changed, 114 insertions(+), 16 deletions(-)
(aei_dropq) HDoupe-MacBook-Pro:PolicyBrain henrydoupe$ py.test webapp/apps/test_assets/test_tcja.py -s -v
======================================================= test session starts =======================================================
platform darwin -- Python 2.7.14, pytest-3.3.0, py-1.5.2, pluggy-0.6.0 -- /anaconda/envs/aei_dropq/bin/python
cachedir: .cache
Django settings: webapp.settings (from ini file)
rootdir: /Users/henrydoupe/Documents/PolicyBrain, inifile: pytest.ini
plugins: django-3.1.2, hypothesis-3.38.5, celery-4.1.0
collected 1 item                                                                                                                  

webapp/apps/test_assets/test_tcja.py::test_tcja_construction _AMT_em
_ID_AllTaxes_c
_STD
_CTC_ps
_PT_brk6
_PT_brk5
_PT_brk4
_PT_brk3
_PT_brk2
_PT_brk1
_AMT_em_ps
_II_brk6
_II_brk5
_II_brk4
_II_brk1
_II_brk3
_II_brk2
_AMT_em
_ID_AllTaxes_c
_STD
_CTC_ps
_PT_brk6
_PT_brk5
_PT_brk4
_PT_brk3
_PT_brk2
_PT_brk1
_AMT_em_ps
_II_brk6
_II_brk5
_II_brk4
_II_brk1
_II_brk3
_II_brk2
PASSED                                                         [100%]

==================================================== 1 passed in 5.18 seconds =====================================================

[GoFroggyRun]

The reform conversion looks pretty cool. I'm not sure, however, whether we want to have a preset for TCJA reconciliation now that tax-calculator is working on making TCJA reconciliation the current law (see #1803). Once that is done (which I think will happen very soon), wouldn't we have to remove this preset after all? On the other hand, a preset link for the current current law would seem more helpful after #1803 is merged into tax-calculator.

@hdoupe @MattHJensen what's your thoughts on this?

[martinholmer]

@hdoupe, You need to work against the TCJA_Reconciliation.json file in Tax-Calculator pull request 1803, which is a corrected version of the one on the master branch as discussed in 1803.

[hdoupe]

Thanks @GoFroggyRun.

I'm not sure, however, whether we want to have a preset for TCJA reconciliation now that tax-calculator is working on making TCJA reconciliation the current law (see #1803).

I saw that. When I put this together, I was under the impression that there would be a delay before the current_law_policy.json file was ready. Further, I was responding to the request in #787.

Once that is done (which I think will happen very soon), wouldn't we have to remove this preset after all? On the other hand, a preset link for the current current law would seem more helpful after #1803 is merged into tax-calculator.

I agree with this.

@martinholmer Thanks for pointing this out. The only change that I need to make is the _ID_Medical_frt parameter, correct?

[martinholmer]

@hdoupe asked about corrections to TCJA_Reconciliation.json file:

Thanks for pointing this out. The only change that I need to make is the _ID_Medical_frt parameter, correct?

Right. The start year is actually 2017 (not 2018). That's the only change.

[hdoupe]

@martinholmer said:

Right. The start year is actually 2017 (not 2018). That's the only change.

Do you mean that the reform start year is 2017? Or, just the start year for _ID_Medical_frt is 2017?

[martinholmer]

@hdoupe asked:

Do you mean that the reform start year is 2017? Or, just the start year for _ID_Medical_frt is 2017?

From Tax-Calculator pull request 1803 we have this change in the taxcalc/reforms/TCJA_Reconciliation.json file:

        "_ID_Medical_frt":
 -            {"2018": [0.075],
 +            {"2017": [0.075],
               "2019": [0.1]},

[hdoupe]

@martinholmer Thanks for clarifying. Please, let me know if this looks better.

[martinholmer]

@hdoupe said:

Please, let me know if this looks better.

Seems correct.