From 6dde0a92ba4caf20a11ea4da97a4d24ba6f5eabb Mon Sep 17 00:00:00 2001
From: Sijawusz Pur Rahnama <sija@sija.pl>
Date: Wed, 19 Feb 2025 02:50:14 +0100
Subject: [PATCH 1/2] Report all literals in `Lint/LiteralInCondition`, except
 for the `case` expression

---
 .../rule/lint/literal_in_condition_spec.cr    | 20 +++++++++++++++++--
 src/ameba/rule/lint/literal_in_condition.cr   | 11 +++++++---
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/spec/ameba/rule/lint/literal_in_condition_spec.cr b/spec/ameba/rule/lint/literal_in_condition_spec.cr
index 5d602f5a2..67d338885 100644
--- a/spec/ameba/rule/lint/literal_in_condition_spec.cr
+++ b/spec/ameba/rule/lint/literal_in_condition_spec.cr
@@ -26,7 +26,23 @@ module Ameba::Rule::Lint
       subject.catch(s).should be_valid
     end
 
-    it "fails if there is a predicate in if conditional" do
+    it "fails if there is a predicate with non-literals" do
+      s = Source.new %(
+        :ok if     [foo, bar]
+        :ok unless [foo, bar]
+
+        while [foo, bar]
+          :ok
+        end
+
+        until [foo, bar]
+          :ok
+        end
+      )
+      subject.catch(s).should_not be_valid
+    end
+
+    it "fails if there is a predicate in `if` conditional" do
       s = Source.new %(
         if "string"
           :ok
@@ -35,7 +51,7 @@ module Ameba::Rule::Lint
       subject.catch(s).should_not be_valid
     end
 
-    it "fails if there is a predicate in unless conditional" do
+    it "fails if there is a predicate in `unless` conditional" do
       s = Source.new %(
         unless true
           :ok
diff --git a/src/ameba/rule/lint/literal_in_condition.cr b/src/ameba/rule/lint/literal_in_condition.cr
index 4678ecba1..150b549ce 100644
--- a/src/ameba/rule/lint/literal_in_condition.cr
+++ b/src/ameba/rule/lint/literal_in_condition.cr
@@ -3,7 +3,7 @@ module Ameba::Rule::Lint
   # in place of a variable or predicate function.
   #
   # This is because a conditional construct with a literal predicate will
-  # always result in the same behaviour at run time, meaning it can be
+  # always result in the same behavior at run time, meaning it can be
   # replaced with either the body of the construct, or deleted entirely.
   #
   # This is considered invalid:
@@ -31,10 +31,15 @@ module Ameba::Rule::Lint
 
     MSG = "Literal value found in conditional"
 
-    def test(source, node : Crystal::If | Crystal::Unless | Crystal::Case)
+    def test(source, node : Crystal::If | Crystal::Unless)
+      issue_for node.cond, MSG if literal?(node.cond)
+    end
+
+    def test(source, node : Crystal::Case)
       return unless cond = node.cond
+      return unless static_literal?(cond)
 
-      issue_for cond, MSG if static_literal?(cond)
+      issue_for cond, MSG
     end
   end
 end

From d5ec13a0a329159b48baf3d11665e0ce726af104 Mon Sep 17 00:00:00 2001
From: Sijawusz Pur Rahnama <sija@sija.pl>
Date: Wed, 19 Feb 2025 02:51:38 +0100
Subject: [PATCH 2/2] Report conditions in `while` and `until` expressions as
 well

---
 .../rule/lint/literal_in_condition_spec.cr    | 36 +++++++++++++++++++
 src/ameba/rule/lint/literal_in_condition.cr   | 10 +++++-
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/spec/ameba/rule/lint/literal_in_condition_spec.cr b/spec/ameba/rule/lint/literal_in_condition_spec.cr
index 67d338885..1388d960f 100644
--- a/spec/ameba/rule/lint/literal_in_condition_spec.cr
+++ b/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 %(
diff --git a/src/ameba/rule/lint/literal_in_condition.cr b/src/ameba/rule/lint/literal_in_condition.cr
index 150b549ce..80c55abf0 100644
--- a/src/ameba/rule/lint/literal_in_condition.cr
+++ b/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