Originally I fixed https://github.com/ruby/syntax_suggest/pull/177 by making the process of comment removal indentation aware. The next commit is the more general fix and means we don't need to carry that additional logic/overhead.
Also: Update syntax via linter
While #177 is reported as being caused by a comment, the underlying behavior is a problem due to the newline that we generated (from a comment). The prior commit fixed that problem by preserving whitespace before the comment. That guarantees that a block will form there from the frontier before it will be expanded there via a "neighbors" method. Since empty lines are valid ruby code, it will be hidden and be safe.
## Problem setup
This failure mode is not fixed by the prior commit, because the indentation is 0. To provide good results, we must make the algorithm less greedy. One heuristic/signal to follow is developer added newlines. If a developer puts a newline between code, it's more likely they're unrelated. For example:
```
port = rand(1000...9999)
stub_request(:any, "localhost:#{port}")
query = Cutlass::FunctionQuery.new(
port: port
).call
expect(WebMock).to have_requested(:post, "localhost:#{port}").
with(body: "{}")
```
This code is split into three chunks by the developer. Each are likely (but not guaranteed) to be intended to stand on their own (in terms of syntax). This behavior is good for scanning neighbors (same indent or higher) within a method, but bad for parsing neighbors across methods.
## Problem
Code is expanded to capture all neighbors, and then it decreases indent level which allows it to capture surrounding scope (think moving from within the method to also capturing the `def/end` definition. Once the indentation level has been increased, we go back to scanning neighbors, but now neighbors also contain keywords.
For example:
```
1 def bark
2
3 end
4
5 def sit
6 end
```
In this case if lines 4, 5, and 6 are in a block when it tries to expand neighbors it will expand up. If it stops after line 2 or 3 it may cause problems since there's a valid kw/end pair, but the block will be checked without it.
TLDR; It's good to stop scanning code after hitting a newline when you're in a method...it causes a problem scanning code between methods when everything inside of one of the methods is an empty line.
In this case it grabs the end on line 3 and since the problem was an extra end, the program now compiles correctly. It incorrectly assumes that the block it captured was causing the problem.
## Extra bit of context
One other technical detail is that after we've decided to stop scanning code for a new neighbor block expansion, we look around the block and grab any empty newlines. Basically adding empty newlines before of after a code block do not affect the parsing of that block.
## The fix
Since we know that this problem only happens when there's a newline inside of a method and we know this particular failure mode is due to having an invalid block (capturing an extra end, but not it's keyword) we have all the metadata we need to detect this scenario and correct it.
We know that the next line above our block must be code or empty (since we grabbed extra newlines). Same for code below it. We can count all the keywords and ends in the block. If they are balanced, it's likely (but not guaranteed) we formed the block correctly. If they're imbalanced, look above or below (depending on the nature of the imbalance), check to see if adding that line would balance the count.
This concept of balance and "leaning" comes from work in https://github.com/ruby/syntax_suggest/pull/152 and has proven useful, but not been formally introduced into the main branch.
## Outcome
Adding this extra check introduced no regressions and fixed the test case. It might be possible there's a mirror or similar problem that we're not handling. That will come out in time. It might also be possible that this causes a worse case in some code not under test. That too would come out in time.
One other possible concern to adding logic in this area (which is a hot codepath), is performance. This extra count check will be performed for every block. In general the two most helpful performance strategies I've found are reducing total number of blocks (therefore reducing overall N internal iterations) and making better matches (the parser to determine if a close block is valid or not is a major bottleneck. If we can split valid code into valid blocks, then it's only evaluated by the parser once, where as invalid code must be continuously re-checked by the parser until it becomes valid, or is determined to be the cause of the core problem.
This extra logic should very rarely result in a change, but when it does it should tend to produce slightly larger blocks (by one line) and more accurate blocks.
Informally it seems to have no impact on performance:
``
This branch:
DEBUG_DISPLAY=1 bundle exec rspec spec/ --format=failures 3.01s user 1.62s system 113% cpu 4.076 total
```
```
On main:
DEBUG_DISPLAY=1 bundle exec rspec spec/ --format=failures 3.02s user 1.64s system 113% cpu 4.098 total
```
https://github.com/ruby/syntax_suggest/commit/13739c6946
When removing comments I previously replaced them with a newline. This loses some context and may affect the order of the indent search which in turn affects the final result. By preserving whitespace in front of the comment, we preserve the "natural" indentation order of the line while also allowing the parser/lexer to see and join naturally consecutive (method chain) lines.
close https://github.com/ruby/syntax_suggest/pull/177
When `tmp/alias` already exists, I'm now getting phantom folders in the directory pointing at older aliases which is distracting/confusing. By checking and removing that alias before symlinking we can prevent this strange behavior (possibly caused by newer Mac OS?).
While working on locking multiple platforms by default, I got an
infinite resolution loop in one of our resolver specs.
The culprit ended up being that when dealing with lockfile specs with
incomplete dependencies (spec appears in lockfile, but its dependencies
don't), those specs were not being properly expired and that tripped up
resolution.
The issue for some reason only manifests when dealing with multiple
lockfile platforms, that's why it only manifested when working on
locking multiple platforms by default.
https://github.com/rubygems/rubygems/commit/4ca72913bb
[Bug #19580]
The real-world scenario motivating this change is libxml2's pthread
code which uses `pthread_key_create` to set up a destructor that is
called at thread exit to free thread-local storage.
There is a small window of time -- after ruby_vm_destruct but before
the process exits -- in which a pthread may exit and the destructor is
called, leading to a segfault.
Please note that this window of time may be relatively large if
`atexit` is being used.
* Test existing behavior
Typing Ctrl-D ends editing but typing <Del> does not.
Also renamed a test that is not testing ed_delete_next_char but
key_delete.
* Check if line empty first in em_delete
By distributivity of AND over OR, we can factor out this condition. This
will make the next commit simpler.
* Use em_delete in key_delete
When the editing mode is emacs, use `em_delete` in `key_delete`. We need
to add a condition though to `em_delete`, because it implements both
`delete-char` and `end-of-file`. We only want the `end-of-file` behavior
is the key is really Ctrl-D.
This matches the behavior of the <Del> key with readline, i.e. deleting
the next character if there is one, but not moving the cursor, while not
finishing the editing if there are no characters.
Remove !USE_RVARGC code
[Feature #19579]
The Variable Width Allocation feature was turned on by default in Ruby
3.2. Since then, we haven't received bug reports or backports to the
non-Variable Width Allocation code paths, so we assume that nobody is
using it. We also don't plan on maintaining the non-Variable Width
Allocation code, so we are going to remove it.