From d6f1954e71e034cc8a278500a663e5ebaf7aafa9 Mon Sep 17 00:00:00 2001
From: Victoria Petrakovich <victoria.petrakovich@jetbrains.com>
Date: Thu, 11 Jun 2026 13:43:07 +0200
Subject: [PATCH] [kotlin] KTIJ-38940 Add/fix K2_ERRORs

(cherry picked from commit 1b4d68597cff30e589b2ba3e674f46c852b313f1)

IJ-CR-214534

GitOrigin-RevId: 1f6ba685d5f3627e42c66c6d1a364140b0cd362b
---
 .../inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt    | 2 +-
 .../safeCastWithReturn/castNeverSucceeds.kt.after               | 2 +-
 .../movePropertyToConstructor/annotationWithUseSite.kt          | 1 +
 .../movePropertyToConstructor/annotationWithUseSite.kt.after    | 1 +
 .../quickfix/expressions/removeUselessIsCheckButFalse.kt        | 1 +
 .../quickfix/expressions/removeUselessIsCheckButFalse.kt.after  | 1 +
 .../quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt  | 1 +
 .../expressions/removeUselessIsCheckInWhenButFalse.kt.after     | 1 +
 .../expressions/removeUselessIsCheckInWhenMultipleConditions.kt | 1 +
 .../removeUselessIsCheckInWhenMultipleConditions.kt.after       | 1 +
 .../removeUselessIsCheckInWhenMultipleConditionsFirst.kt        | 1 +
 .../removeUselessIsCheckInWhenMultipleConditionsFirst.kt.after  | 1 +
 .../expressions/removeUselessIsCheckInWhenNegateButTrue.kt      | 1 +
 .../removeUselessIsCheckInWhenNegateButTrue.kt.after            | 1 +
 .../quickfix/expressions/removeUselessIsCheckNegateButTrue.kt   | 1 +
 .../expressions/removeUselessIsCheckNegateButTrue.kt.after      | 1 +
 16 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt b/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt
index a4581d5a6ba8..d3dcbb8c5a20 100644
--- a/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt
+++ b/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt
@@ -1,5 +1,5 @@
 // AFTER_ERROR: Incompatible types: String and Int
-// K2_AFTER_ERROR:
+// K2_AFTER_ERROR: Check for instance is always 'true'.
 fun test(x: Int) {
     <caret>x as? String //comment1
             ?: return
diff --git a/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt.after b/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt.after
index 44e64b11734c..71e486859b81 100644
--- a/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt.after
+++ b/plugins/kotlin/code-insight/inspections-k2/tests/testData/inspectionsLocal/safeCastWithReturn/castNeverSucceeds.kt.after
@@ -1,5 +1,5 @@
 // AFTER_ERROR: Incompatible types: String and Int
-// K2_AFTER_ERROR:
+// K2_AFTER_ERROR: Check for instance is always 'true'.
 fun test(x: Int) {
     if (x !is String //comment1
     ) return
diff --git a/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt b/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt
index c5416db290a2..fc663d02d443 100644
--- a/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt
+++ b/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt
@@ -1,3 +1,4 @@
+// K2_AFTER_ERROR: This annotation is not repeatable.
 annotation class Annotation1(val a: Int = 0)
 annotation class Annotation2(val a: Int = 0)
 annotation class Annotation3(val a: Int = 0)
diff --git a/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt.after b/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt.after
index 6155eb144ccc..aae81421365c 100644
--- a/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt.after
+++ b/plugins/kotlin/idea/tests/testData/intentions/movePropertyToConstructor/annotationWithUseSite.kt.after
@@ -1,3 +1,4 @@
+// K2_AFTER_ERROR: This annotation is not repeatable.
 annotation class Annotation1(val a: Int = 0)
 annotation class Annotation2(val a: Int = 0)
 annotation class Annotation3(val a: Int = 0)
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt
index 371bbaa5b838..8c2613e325aa 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 fun foo(a: String) {
     if (<caret>a is Int) {
 
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt.after b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt.after
index e765d3abf040..a2300d69a526 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt.after
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckButFalse.kt.after
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 fun foo(a: String) {
     if (<caret>false) {
 
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt
index 643075d7ba3a..17d0b4a84d61 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 
 interface Base
 interface Derived: Base
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt.after b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt.after
index abe9fa10dfc1..0a41b73bf1c1 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt.after
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenButFalse.kt.after
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 
 interface Base
 interface Derived: Base
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt
index c2e5999a928c..222b85b994d5 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 open class A
 class B: A()
 class C: A()
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt.after b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt.after
index ac18314c8540..11da529003f0 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt.after
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditions.kt.after
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 open class A
 class B: A()
 class C: A()
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt
index 37c9bef4f7e5..38b21f16c981 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 open class A
 class B: A()
 class C: A()
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt.after b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt.after
index ac18314c8540..11da529003f0 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt.after
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenMultipleConditionsFirst.kt.after
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'false'.
 open class A
 class B: A()
 class C: A()
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt
index 94a55e9fb58d..6c9e86eda5ba 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'true'.
 
 interface Base
 interface Derived: Base
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt.after b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt.after
index 3b168b758c3b..06f1a383708f 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt.after
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckInWhenNegateButTrue.kt.after
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'true'.
 
 interface Base
 interface Derived: Base
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt
index f590ee601a1b..53b2f571e3df 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'true'.
 fun foo(a: String) {
     if (<caret>a !is Int) {
 
diff --git a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt.after b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt.after
index e01a12fcef1e..bdd358b6cc0d 100644
--- a/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt.after
+++ b/plugins/kotlin/idea/tests/testData/quickfix/expressions/removeUselessIsCheckNegateButTrue.kt.after
@@ -1,4 +1,5 @@
 // "Remove redundant 'is' check" "true"
+// K2_ERROR: Check for instance is always 'true'.
 fun foo(a: String) {
     if (<caret>true) {