From 3e14d4f80f99360d45923f0f6170c71e0b0b26b2 Mon Sep 17 00:00:00 2001
From: Johnnei <jtiesinga@gmail.com>
Date: Mon, 16 Jan 2023 21:58:05 +0700
Subject: [PATCH] Allow unit results in if statement if they're captured by a
 function

Fixes #229
---
 .../inspections/empty/EmptyIfBlock.scala      |  2 ++
 .../inspections/empty/EmptyIfBlockTest.scala  | 24 ++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/main/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlock.scala b/src/main/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlock.scala
index 14907a21..8f259454 100644
--- a/src/main/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlock.scala
+++ b/src/main/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlock.scala
@@ -23,6 +23,8 @@ class EmptyIfBlock
 
           override def inspect(tree: Tree): Unit = {
             tree match {
+              // Function directly contains if, an empty block would generate Unit (or Any) output type
+              case Function(_, If(_, Literal(Constant(())), _)) => // skip tree
               case If(_, Literal(Constant(())), _) =>
                 context.warn(tree.pos, self, tree.toString.take(500))
               case _ => continue(tree)
diff --git a/src/test/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlockTest.scala b/src/test/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlockTest.scala
index c02b4eda..e3757b71 100644
--- a/src/test/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlockTest.scala
+++ b/src/test/scala/com/sksamuel/scapegoat/inspections/empty/EmptyIfBlockTest.scala
@@ -10,7 +10,8 @@ class EmptyIfBlockTest extends InspectionTest {
   "empty if block" - {
     "should report warning" in {
 
-      val code = """object Test {
+      val code =
+        """object Test {
 
                       if (true) {
                       }
@@ -28,5 +29,26 @@ class EmptyIfBlockTest extends InspectionTest {
       compileCodeSnippet(code)
       compiler.scapegoat.feedback.warnings.size shouldBe 2
     }
+
+    "should not report warning" - {
+      "the if-block is the return value" in {
+        val code =
+          """
+            |import scala.concurrent.Future
+            |import scala.concurrent.ExecutionContext.Implicits.global
+            |object Test {
+            |  Future("test").map(value => {
+            |   if (value.contains("foo")) {
+            |     ()
+            |   } else {
+            |     throw new IllegalStateException("Bar!")
+            |   }
+            |  })
+            |}""".stripMargin
+
+        compileCodeSnippet(code)
+        compiler.scapegoat.feedback.warnings.size shouldBe 0
+      }
+    }
   }
 }