Add RuboCop RSpec support

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## master (unrealeased)
 
+- Add support for RSpec aliases detection when linting specs using `let_it_be`/`before_all` with `rubocop-rspec` 2.0 ([@pirj][])
+
 ## 0.12.2 (2020-09-03)
 
 - Execute Minitest `before_all` in the context of the current test object. ([@palkan][])

config/rubocop-rspec.yml

@@ -0,0 +1,6 @@
+RSpec:
+  Language:
+    Helpers:
+      - let_it_be
+    Hooks:
+      - before_all

docs/README.md

@@ -88,6 +88,16 @@ Supported Ruby versions:
 
 Supported RSpec version (for RSpec features only): >= 3.5.0 (for older RSpec version use TestProf < 0.8.0).
 
+### Linting with RuboCop RSpec
+
+When you lint your RSpec spec files with `rubocop-rspec`, it will fail to properly detect RSpec constructs that TestProf defines, `let_it_be` and `before_all`.
+Make sure to use `rubocop-rspec` 2.0 or newer and add the following to your `.rubocop.yml`:
+
+```yaml
+inherit_gem:
+  test-prof: config/rubocop-rspec.yml
+```
+
 ## Profilers
 
 - [RubyProf Integration](./profilers/ruby_prof.md)