[Fix #12146] Fix a false positive for Lint/FloatComparison

changelog/fix_a_false_positive_for_float_comparision_with_zero_nonzero.md

@@ -0,0 +1 @@
+* [#12146](https://github.com/rubocop/rubocop/issues/12146): Fix a false positive for `Lint/FloatComparison` when comparing against zero. ([@earlopain][])

lib/rubocop/cop/lint/float_comparison.rb

@@ -18,6 +18,10 @@ module Lint
       #   # good - using BigDecimal
       #   x.to_d == 0.1.to_d
       #
+      #  # good - comparing against zero
+      #   x == 0.0
+      #   x != 0.0
+      #
       #   # good
       #   (x - 0.1).abs < Float::EPSILON
       #
@@ -39,6 +43,8 @@ class FloatComparison < Base
 
         def on_send(node)
           lhs, _method, rhs = *node
+          return if literal_zero?(lhs) || literal_zero?(rhs)
+
           add_offense(node) if float?(lhs) || float?(rhs)
         end
 
@@ -59,6 +65,10 @@ def float?(node)
           end
         end
 
+        def literal_zero?(node)
+          node&.numeric_type? && node.value.zero?
+        end
+
         # rubocop:disable Metrics/PerceivedComplexity
         def check_send(node)
           if node.arithmetic_operation?

spec/rubocop/cop/lint/float_comparison_spec.rb

@@ -67,4 +67,16 @@
       (x - 0.1) < epsilon
     RUBY
   end
+
+  it 'does not register an offense when comparing against zero' do
+    expect_no_offenses(<<~RUBY)
+      x == 0.0
+      x.to_f == 0
+      x.to_f.abs == 0.0
+      x != 0.0
+      x.to_f != 0
+      x.to_f.zero?
+      x.to_f.nonzero?
+    RUBY
+  end
 end