Style/SpaceBeforeBlockBraces doesn't run when Style/BlockDelimiters is enabled

[DexterTheDragon]

When using the Style/SpaceBeforeBlockBraces cop if the Style/BlockDelimiters is also enabled then the Style/SpaceBeforeBlockBraces cop is not run. The code (space_before_block_braces.rb#L15-L22) implies that this is intentional saying that if you use braces for a multi-line block then you will get a warning to replace it with do...end in which case the space before the brace doesn't matter. But this is only true when using the Style/BlockDelimiters EnforcedStyle setting of line_count_based, which prohibits mutli-line blocks using braces.

But if you use the EnforcedStyle setting of either semantic or braces_for_chaining, both of which allow multi-line blocks to use braces is some cases, then you expect to get a warning from Style/SpaceBeforeBlockBraces and don't.

---

Steps to reproduce the problem

test.rb

foo.map{ |a|
  a.bar.to_s
}

test.yml

Style/BlockDelimiters:  
  Enabled: true
  EnforcedStyle: semantic

Style/SpaceBeforeBlockBraces:          
  Enabled: true

$ rubocop --config test.yml --only Style/SpaceBeforeBlockBraces test.rb

Expected behavior

Offenses:

test.rb:1:8: C: Space missing to the left of {.
foo.map{ |a|
       ^

1 file inspected, 1 offense detected

Actual behavior

1 file inspected, no offenses detected

RuboCop version

$ rubocop -V
0.42.0 (using Parser 2.3.1.2, running on ruby 2.3.1 x86_64-linux)