Report conditions in while and until expressions as well

spec/ameba/rule/lint/literal_in_condition_spec.cr

@@ -60,6 +60,42 @@ module Ameba::Rule::Lint
       subject.catch(s).should_not be_valid
     end
 
+    it "fails if there is a predicate in `while` conditional" do
+      s = Source.new %(
+        while 1
+          :ok
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "fails if there is a `false` predicate in `while` conditional" do
+      s = Source.new %(
+        while false
+          :ok
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "passes if there is a `true` predicate in `while` conditional" do
+      s = Source.new %(
+        while true
+          :ok
+        end
+      )
+      subject.catch(s).should be_valid
+    end
+
+    it "fails if there is a predicate in `until` conditional" do
+      s = Source.new %(
+        until true
+          :foo
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
     describe "range" do
       it "reports range with literals" do
         s = Source.new %(

src/ameba/rule/lint/literal_in_condition.cr

@@ -31,7 +31,7 @@ module Ameba::Rule::Lint
 
     MSG = "Literal value found in conditional"
 
-    def test(source, node : Crystal::If | Crystal::Unless)
+    def test(source, node : Crystal::If | Crystal::Unless | Crystal::Until)
       issue_for node.cond, MSG if literal?(node.cond)
     end
 
@@ -41,5 +41,13 @@ module Ameba::Rule::Lint
 
       issue_for cond, MSG
     end
+
+    def test(source, node : Crystal::While)
+      return unless literal?(cond = node.cond)
+      # allow `while true`
+      return if cond.is_a?(Crystal::BoolLiteral) && cond.value
+
+      issue_for cond, MSG
+    end
   end
 end