rename refactor

[aviatesk]

UPDATED: moved to #203

---

Purpose

Implement rename refactoring command:

• rename local binding
• rename global bindings (module-based)

Approach

• use MacroTools.jl for easy tokenizing and code replacing
• for module-based global refactoring, CSTParser-based static file detection is used:
  • since our Revise-like module file detection will easily fail with the refactorings, which breaks precompilation cache
• first tries local refactoring, and then move to global refactoring if needed
• rename refactoring on fields is all suppressed, since not every code is statically typed and so I think we would end up with lots of false positive
• global refactoring are designed to work only when it's called on the definition place

Task / Achievements

• local refactor
• module-based global refactor
• graceful messages
  • notice the need of refactoring in the parent module if the refactored binding is imported/overloaded
  • report back error message
  • notice refactored files
  • show context
• handle edge cases
  • suppress keyword refactoring
  • suppress field refactoring
  • suppress global refactoring that are not called at a definition place
  • halt global refactoring if files without write permission detected
  • global refactoring with dot accessor like Atom.isdebugging(), Base.countlines(args...)
  • global refactoring on macro
• test

[aviatesk]

xref: JunoLab/atom-julia-client#641
xref: JunoLab/atom-ink#236

[aviatesk]

woa, travis has been revived ! :)

[codecov]

Codecov Report

Merging #202 into master will decrease coverage by 2.04%.
The diff coverage is 12.19%.

@@            Coverage Diff             @@
##           master     #202      +/-   ##
==========================================
- Coverage   39.52%   37.48%   -2.05%     
==========================================
  Files          36       37       +1     
  Lines        1824     1934     +110     
==========================================
+ Hits          721      725       +4     
- Misses       1103     1209     +106

Impacted Files	Coverage Δ
src/Atom.jl	100% <ø> (ø)	⬆️
src/refactor.jl	0% <0%> (ø)
src/docs.jl	0% <0%> (ø)	⬆️
src/utils.jl	85.54% <37.93%> (-9.82%)	⬇️
src/completions.jl	76.99% <80%> (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 117a5f4...b8802f3. Read the comment docs.

[aviatesk]

I agree the logic here would look messy, so please feel free to ask me if you have anything unsure -- I probably miss some edge cases.

[aviatesk]

Here are some edge cases I've noticed but still I'm not sure about how to handle.

local refactoring

If we have the code like:

function outer()
  val = 10
  function inner(val)
    2 * val
  end
  return inner(val)
end

and we refactor on outer's val, the inner's vals are also refactored, even though we may want to only refactor outers.
This is obviously because the inner function is included in the outer function scope, but I still not found any good way to handle this case with MacroTools's source walk.
As an alternative, this case would be easily solved if we can directly manipulate CSTParser's expressions and then reconstruct the source appropriately. But I'm not sure even if it's possible.

global refactoring

If a module contains code like:

function fun() end

function other()
  fun = 10
end

and we rename fun to fun2, then the binding fun in other will also be renamed to fun2. This is because I intentionally looks just for fun tokens, not for something more complicated like call sites (the code here), since in Julia every binding is an object, and we can have a code like map(fun, itr).
Current behavior can be annoying, but at least doesn't break code. If we just looks for call sites, then we may have false negatives, which would break the code. So imho the current behavior may suffice.

[aviatesk]

Damn, I missed to push to the master ! Will try to revert all the commits.

[aviatesk]

Okay, sorry for the confusing.
283d466 (on master) successfully reverted all the commits in this PR that were mistakenly pushed to master.
And this PR is moved into #203.