Tell SimpleCov to ignore unreachable code

In some cases we know that a case statement is covering all possible
branches, e.g. `case [foo?, bar?]` has four branches (if the predicate
methods return booleans, of course), and `case style` has a know number
of branches, depending on `SupportedStyles` in config/default.yml.

So, when to use `else ... raise ArgumentError`, and when to change the
last `elsif` or `when` into an `else`? I don't know.

.simplecov

@@ -2,7 +2,7 @@
 
 SimpleCov.start do
   enable_coverage :branch
-  minimum_coverage line: 100, branch: 98.44
+  minimum_coverage line: 100, branch: 99.6
   add_filter '/spec/'
   add_filter '/vendor/bundle/'
 end

lib/rubocop/cop/rspec/be_nil.rb

@@ -48,6 +48,10 @@ def on_send(node)
             check_be_style(node)
           when :be_nil
             check_be_nil_style(node)
+          else
+            # :nocov:
+            raise ArgumentError("Unsupported style :#{style}")
+            # :nocov:
           end
         end
 

lib/rubocop/cop/rspec/example_wording.rb

@@ -128,7 +128,7 @@ def text(node)
             node.node_parts.map { |child_node| text(child_node) }.join
           when :str
             node.value
-          when :begin
+          else
             node.source
           end
         end

lib/rubocop/cop/rspec/excessive_docstring_spacing.rb

@@ -100,7 +100,7 @@ def text(node)
             node.node_parts.map { |child_node| text(child_node) }.join
           when :str, :sym
             node.value
-          when :begin
+          else
             node.source
           end
         end

lib/rubocop/cop/rspec/implicit_subject.rb

@@ -97,6 +97,7 @@ def on_send(node)
 
         private
 
+        # rubocop:disable Metrics/MethodLength
         def autocorrect(corrector, node)
           case node.method_name
           when :expect
@@ -107,8 +108,13 @@ def autocorrect(corrector, node)
             corrector.replace(node.location.selector, 'expect(subject).to')
           when :should_not
             corrector.replace(node.location.selector, 'expect(subject).not_to')
+          else
+            # :nocov:
+            raise ArgumentError("Unexpected method name #{node.method_name}")
+            # :nocov:
           end
         end
+        # rubocop:enable Metrics/MethodLength
 
         def message(_node)
           case style
@@ -119,6 +125,7 @@ def message(_node)
           end
         end
 
+        # rubocop:disable Metrics/MethodLength
         def invalid?(node)
           case style
           when :require_implicit
@@ -129,8 +136,13 @@ def invalid?(node)
             implicit_subject_in_non_its_and_non_single_line?(node)
           when :single_statement_only
             implicit_subject_in_non_its_and_non_single_statement?(node)
+          else
+            # :nocov:
+            raise ArgumentError("Unsupported style :#{style}")
+            # :nocov:
           end
         end
+        # rubocop:enable Metrics/MethodLength
 
         def implicit_subject_in_non_its?(node)
           implicit_subject?(node) && !its?(node)

lib/rubocop/cop/rspec/message_spies.rb

@@ -80,6 +80,10 @@ def error_message(receiver)
             MSG_RECEIVE
           when :have_received
             format(MSG_HAVE_RECEIVED, source: receiver.source)
+          else
+            # :nocov:
+            raise ArgumentError("Unsupported style :#{style}")
+            # :nocov:
           end
         end
       end

lib/rubocop/cop/rspec/predicate_matcher.rb

@@ -110,7 +110,7 @@ def true?(to_symbol, matcher)
                      matcher.first_argument.true_type?
                    when :be_truthy, :a_truthy_value
                      true
-                   when :be_falsey, :be_falsy, :a_falsey_value, :a_falsy_value
+                   else # :be_falsey, :be_falsy, :a_falsey_value, :a_falsy_value
                      false
                    end
           to_symbol == :to ? result : !result
@@ -260,7 +260,7 @@ def replacement_matcher(node)
             'be(false)'
           when [false, true]
             'be_truthy'
-          when [false, false]
+          else
             'be_falsey'
           end
         end
@@ -329,6 +329,10 @@ def on_send(node)
             check_inflected(node)
           when :explicit
             check_explicit(node)
+          else
+            # :nocov:
+            raise ArgumentError("Unsupported style :#{style}")
+            # :nocov:
           end
         end