[PowerAssert] Reproduce KT-66208

plugins/power-assert/testData/codegen/cast/InstanceEquals.box.txt

@@ -1,4 +1,35 @@
 Assertion failed
 assert(null is String)
             |
-            false
+            false
+
+Assertion failed
+assert(!(" is " is String))
+       |   |
+       |   true
+       false
+
+Assertion failed
+assert(!(
+       |
+       false
+    " is "
+      |
+      true
+
+            is
+
+            String
+))
+
+Assertion failed
+assert(null/*is*/is/*is*/String)
+       |
+       false
+
+Assertion failed
+assert(!((null is String) is Boolean))
+       |       |
+       |       true
+       |       false
+       false

plugins/power-assert/testData/codegen/cast/InstanceEquals.kt

@@ -1,3 +1,21 @@
 fun box() = expectThrowableMessage {
     assert(null is String)
+} + "\n\n" + expectThrowableMessage {
+    // Test that we don't just search for `is` in the expression.
+    assert(!(" is " is String))
+} + "\n\n" + expectThrowableMessage {
+    // Test multiline case
+    assert(!(
+        " is "
+
+                is
+
+                String
+    ))
+} + "\n\n" + expectThrowableMessage {
+    // Test that we don't assume whitespaces around the operator
+    assert(null/*is*/is/*is*/String)
+} + "\n\n" + expectThrowableMessage {
+    // Test nested `is`
+    assert(!((null is String) is Boolean))
 }

plugins/power-assert/testData/codegen/cast/InstanceNotEquals.box.txt

@@ -1,4 +1,31 @@
 Assertion failed
 assert("Hello, world!" !is String)
                        |
-                       false
+                       false
+
+Assertion failed
+assert(" !is " !is String)
+         |
+         false
+
+Assertion failed
+assert(
+    " !is "
+      |
+      false
+
+            !is
+
+            String
+)
+
+Assertion failed
+assert("Hello, world!"/*!is*/!is/*!is*/String)
+       |
+       false
+
+Assertion failed
+assert(("Hello, world!" !is String) !is Boolean)
+                        |
+                        false
+                        false

plugins/power-assert/testData/codegen/cast/InstanceNotEquals.kt

@@ -1,3 +1,21 @@
 fun box() = expectThrowableMessage {
     assert("Hello, world!" !is String)
+} + "\n\n" + expectThrowableMessage {
+    // Test that we don't just search for `!is` in the expression.
+    assert(" !is " !is String)
+} + "\n\n" + expectThrowableMessage {
+    // Test multiline case
+    assert(
+        " !is "
+
+                !is
+
+                String
+    )
+} + "\n\n" + expectThrowableMessage {
+    // Test that we don't assume whitespaces around the operator
+    assert("Hello, world!"/*!is*/!is/*!is*/String)
+} + "\n\n" + expectThrowableMessage {
+    // Test nested `!is`
+    assert(("Hello, world!" !is String) !is Boolean)
 }