Move JSON check to CodeGen rather than as helper function

[bchen1116]

fix #1495

Follow-up on this pr. Moved JSON check to CodeGen function, added additional tests

[codecov]

Codecov Report

Merging #1531 (de3e243) into main (6aac72d) will increase coverage by 0.1%.
The diff coverage is 100.0%.

@@            Coverage Diff            @@
##             main    #1531     +/-   ##
=========================================
+ Coverage   100.0%   100.0%   +0.1%     
=========================================
  Files         230      230             
  Lines       15824    15831      +7     
=========================================
+ Hits        15816    15823      +7     
  Misses          8        8             

Impacted Files	Coverage Δ
evalml/pipelines/utils.py	100.0% <100.0%> (ø)
evalml/tests/pipeline_tests/test_pipelines.py	100.0% <100.0%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6aac72d...de3e243. Read the comment docs.

[dsherry]

@bchen1116 did you mean to put this in Review instead of In Progress? I see there are test failures so unsure if its ready for review

[bchen1116]

@dsherry it's In Progress for me, but I'll fix these tests and get it up for review soon

[jeremyliweishih]

Is this just to address Dylan's comments? If so, LGTM!

[dsherry]

🚢 looks great!

[angela97lin]

Nice, LGTM! 👍