[FIR-TEST] Add test for KT-39075

compiler/fir/analysis-tests/testData/resolve/inference/coercionToUnitWithEarlyReturn.kt

+// ISSUE: KT-39075
+
+class A {
+    fun unit() {}
+}
+
+fun foo(x: () -> Unit) {}
+
+fun main(x: A?) {
+
+    val lambda = l@{
+        if (x?.hashCode() == 0) return@l
+
+        x?.unit()
+    }
+
+    // lambda has a type (() -> Unit?)
+    foo(lambda)
+}
\ No newline at end of file

compiler/fir/analysis-tests/testData/resolve/inference/coercionToUnitWithEarlyReturn.txt

+FILE: coercionToUnitWithEarlyReturn.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun unit(): R|kotlin/Unit| {
+        }
+
+    }
+    public final fun foo(x: R|() -> kotlin/Unit|): R|kotlin/Unit| {
+    }
+    public final fun main(x: R|A?|): R|kotlin/Unit| {
+        lval lambda: R|() -> kotlin/Unit| = l@fun <anonymous>(): R|kotlin/Unit| {
+            when () {
+                ==(R|<local>/x|?.{ $subj$.R|kotlin/Any.hashCode|() }, Int(0)) ->  {
+                    ^@l Unit
+                }
+            }
+
+            ^ R|<local>/x|?.{ $subj$.R|/A.unit|() }
+        }
+
+        R|/foo|(R|<local>/lambda|)
+    }

compiler/fir/analysis-tests/tests/org/jetbrains/kotlin/fir/FirDiagnosticsTestGenerated.java

@@ -1469,6 +1469,11 @@ public class FirDiagnosticsTestGenerated extends AbstractFirDiagnosticsTest {
             runTest("compiler/fir/analysis-tests/testData/resolve/inference/capturedTypeForJavaTypeParameter.kt");
         }
 
+        @TestMetadata("coercionToUnitWithEarlyReturn.kt")
+        public void testCoercionToUnitWithEarlyReturn() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/inference/coercionToUnitWithEarlyReturn.kt");
+        }
+
         @TestMetadata("definitelyNotNullIntersectionType.kt")
         public void testDefinitelyNotNullIntersectionType() throws Exception {
             runTest("compiler/fir/analysis-tests/testData/resolve/inference/definitelyNotNullIntersectionType.kt");

compiler/fir/analysis-tests/tests/org/jetbrains/kotlin/fir/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -1469,6 +1469,11 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             runTest("compiler/fir/analysis-tests/testData/resolve/inference/capturedTypeForJavaTypeParameter.kt");
         }
 
+        @TestMetadata("coercionToUnitWithEarlyReturn.kt")
+        public void testCoercionToUnitWithEarlyReturn() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/inference/coercionToUnitWithEarlyReturn.kt");
+        }
+
         @TestMetadata("definitelyNotNullIntersectionType.kt")
         public void testDefinitelyNotNullIntersectionType() throws Exception {
             runTest("compiler/fir/analysis-tests/testData/resolve/inference/definitelyNotNullIntersectionType.kt");