[FIR] Report PROPERTY_WITH_NO_TYPE_NO_INITIALIZER for all properties

Currently, PROPERTY_WITH_NO_TYPE_NO_INITIALIZER is reported for local
variables, but not reported for member or top-level properties. Add a
check to the common `checkPropertyInitializer` for when a property
type cannot be determined from the getter.

This also corrects a K1 versus K2 inconsistency, where K2 would allow
blocks from getters to determine property type instead of only allowing
expression bodies.

^KT-59935 Fixed
^KT-60117 Fixed
^KT-60123 Fixed

analysis/low-level-api-fir/testData/inBlockModification/memberGetterWithoutTypeWithBody.txt

@@ -1,9 +1,9 @@
 BEFORE MODIFICATION:
-public final [ResolvedTo(BODY_RESOLVE)] val x: R|kotlin/Int|
+public final [ResolvedTo(BODY_RESOLVE)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=A] get(): R|kotlin/Int| {
+    public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=A] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
         ^ R|/doSmth|(String(str))
     }
 
 AFTER MODIFICATION:
-public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: R|kotlin/Int|
+public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(ANNOTATION_ARGUMENTS)] [ContainingClassKey=A] get(): R|kotlin/Int| { LAZY_BLOCK }
+    public [ResolvedTo(ANNOTATION_ARGUMENTS)] [ContainingClassKey=A] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> { LAZY_BLOCK }

analysis/low-level-api-fir/testData/inBlockModification/memberGetterWithoutTypeWithBodyScript.txt

@@ -1,9 +1,9 @@
 BEFORE MODIFICATION:
-public final [ResolvedTo(BODY_RESOLVE)] val x: R|kotlin/Int|
+public final [ResolvedTo(BODY_RESOLVE)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=A] get(): R|kotlin/Int| {
+    public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=A] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
         ^ R|/doSmth|(String(str))
     }
 
 AFTER MODIFICATION:
-public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: R|kotlin/Int|
+public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(ANNOTATION_ARGUMENTS)] [ContainingClassKey=A] get(): R|kotlin/Int| { LAZY_BLOCK }
+    public [ResolvedTo(ANNOTATION_ARGUMENTS)] [ContainingClassKey=A] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> { LAZY_BLOCK }

analysis/low-level-api-fir/testData/inBlockModification/topLevelGetterWithoutTypeWithBody.txt

@@ -1,9 +1,9 @@
 BEFORE MODIFICATION:
-public final [ResolvedTo(BODY_RESOLVE)] val x: R|kotlin/Int|
+public final [ResolvedTo(BODY_RESOLVE)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(BODY_RESOLVE)] get(): R|kotlin/Int| {
+    public [ResolvedTo(BODY_RESOLVE)] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
         ^ R|/doSmth|(String(str))
     }
 
 AFTER MODIFICATION:
-public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: R|kotlin/Int|
+public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(ANNOTATION_ARGUMENTS)] get(): R|kotlin/Int| { LAZY_BLOCK }
+    public [ResolvedTo(ANNOTATION_ARGUMENTS)] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> { LAZY_BLOCK }

analysis/low-level-api-fir/testData/inBlockModification/topLevelGetterWithoutTypeWithBodyScript.txt

@@ -1,9 +1,9 @@
 BEFORE MODIFICATION:
-public final [ResolvedTo(BODY_RESOLVE)] val x: R|kotlin/Int|
+public final [ResolvedTo(BODY_RESOLVE)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(BODY_RESOLVE)] get(): R|kotlin/Int| {
+    public [ResolvedTo(BODY_RESOLVE)] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
         ^ R|/doSmth|(String(str))
     }
 
 AFTER MODIFICATION:
-public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: R|kotlin/Int|
+public final [ResolvedTo(ANNOTATION_ARGUMENTS)] val x: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-    public [ResolvedTo(ANNOTATION_ARGUMENTS)] get(): R|kotlin/Int| { LAZY_BLOCK }
+    public [ResolvedTo(ANNOTATION_ARGUMENTS)] get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> { LAZY_BLOCK }

compiler/fir/analysis-tests/testData/resolve/propertyGetterWithoutType.fir.txt

@@ -1,6 +1,6 @@
 FILE: propertyGetterWithoutType.kt
-    public final val prop: <ERROR TYPE REF: empty body>
+    public final val prop: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-        public get(): <ERROR TYPE REF: empty body> {
+        public get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
             local final fun smth(s: R|kotlin/String|): R|kotlin/Int| {
                 ^smth Int(1)
             }

compiler/fir/analysis-tests/testData/resolve/propertyGetterWithoutType.kt

@@ -1,5 +1,5 @@
 // ISSUE: KT-59649
-val prop
+<!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>val prop<!>
     get() {
         fun smth(s: String) = 1
         return smth("awd")

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/untypedPropertyWithBackingFieldUsage.fir.txt

@@ -1,6 +1,6 @@
 FILE: untypedPropertyWithBackingFieldUsage.kt
-    public final val simpleNoTypeBlock: <ERROR TYPE REF: Unresolved name: field>
+    public final val simpleNoTypeBlock: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
-        public get(): <ERROR TYPE REF: Unresolved name: field> {
+        public get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
             ^ <Unresolved name: field>#
         }
     public final val simpleNoTypeExpression: <ERROR TYPE REF: Unresolved name: field>
@@ -15,9 +15,9 @@ FILE: untypedPropertyWithBackingFieldUsage.kt
         public get(): R|kotlin/Int| {
             ^ F|/simpleTypeExpression|
         }
-    public final val withFieldNoTypeBlock: R|kotlin/Int|
+    public final val withFieldNoTypeBlock: <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate>
         private <explicit backing field>: R|kotlin/Double| = Double(3.14)
-        public get(): R|kotlin/Int| {
+        public get(): <ERROR TYPE REF: Cannot infer variable type without initializer / getter / delegate> {
             ^ <Unresolved name: field>#.R|kotlin/text/toInt|()
         }
     public final val withFieldNoTypeExpression: R|kotlin/Int|

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/untypedPropertyWithBackingFieldUsage.kt

@@ -1,4 +1,4 @@
-val simpleNoTypeBlock
+<!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>val simpleNoTypeBlock<!>
     get() {
         return <!UNRESOLVED_REFERENCE!>field<!>
     }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelPropertiesChecker.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.fir.resolve.dfa.cfg.NormalPath
 import org.jetbrains.kotlin.fir.resolve.dfa.controlFlowGraph
 import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeLocalVariableNoTypeOrInitializer
 import org.jetbrains.kotlin.fir.types.FirErrorTypeRef
+import org.jetbrains.kotlin.fir.types.FirTypeRef
 import org.jetbrains.kotlin.lexer.KtTokens
 
 // See old FE's [DeclarationsChecker]
@@ -85,7 +86,7 @@ internal fun checkPropertyInitializer(
         val returnTypeRef = property.returnTypeRef
         if (property.initializer == null &&
             property.delegate == null &&
-            returnTypeRef is FirErrorTypeRef && returnTypeRef.diagnostic is ConeLocalVariableNoTypeOrInitializer
+            returnTypeRef.noExplicitType()
         ) {
             property.source?.let {
                 reporter.reportOn(it, FirErrors.PROPERTY_WITH_NO_TYPE_NO_INITIALIZER, context)
@@ -171,7 +172,14 @@ internal fun checkPropertyInitializer(
                         )
                     }
                 }
+            } else if (
+                property.returnTypeRef.noExplicitType() &&
+                !property.hasExplicitBackingField &&
+                (property.getter is FirDefaultPropertyAccessor || (property.getter?.hasBody == true && property.getter?.returnTypeRef?.noExplicitType() == true))
+            ) {
+                reporter.reportOn(propertySource, FirErrors.PROPERTY_WITH_NO_TYPE_NO_INITIALIZER, context)
             }
+
             if (property.isLateInit) {
                 if (isExpect) {
                     reporter.reportOn(propertySource, FirErrors.EXPECTED_LATEINIT_PROPERTY, context)
@@ -187,6 +195,10 @@ internal fun checkPropertyInitializer(
     }
 }
 
+private fun FirTypeRef.noExplicitType(): Boolean {
+    return this is FirErrorTypeRef && diagnostic is ConeLocalVariableNoTypeOrInitializer
+}
+
 private fun reportMustBeInitialized(
     property: FirProperty,
     isDefinitelyAssigned: Boolean,

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirDeclarationsResolveTransformer.kt

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.fir.declarations.utils.isLocal
 import org.jetbrains.kotlin.fir.diagnostics.ConeSimpleDiagnostic
 import org.jetbrains.kotlin.fir.diagnostics.DiagnosticKind
 import org.jetbrains.kotlin.fir.expressions.*
+import org.jetbrains.kotlin.fir.expressions.impl.FirSingleExpressionBlock
 import org.jetbrains.kotlin.fir.references.FirResolvedErrorReference
 import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
 import org.jetbrains.kotlin.fir.resolve.*
@@ -1211,7 +1212,7 @@ open class FirDeclarationsResolveTransformer(
                     val unwrappedInitializer = initializer.unwrapSmartcastExpression()
                     unwrappedInitializer.resolvedType.toFirResolvedTypeRef()
                 }
-                variable.getter != null && variable.getter !is FirDefaultPropertyAccessor -> variable.getter?.returnTypeRef
+                variable.getter?.body is FirSingleExpressionBlock -> variable.getter?.returnTypeRef
                 else -> null
             }
 

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/blockBodyGetter.fir.kt

@@ -1,3 +0,0 @@
-val x get() {
-    return 1
-}

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/blockBodyGetter.kt

@@ -1,3 +1,7 @@
+// FIR_IDENTICAL
+
 <!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>val x<!> get() {
     return 1
 }
+
+val y get() = 1

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/blockBodyGetter.txt

@@ -1,3 +1,5 @@
 package
 
 public val x: [Error type: Return type for property x cannot be resolved]
+public val y: kotlin.Int
+

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/primaryConstructorParameter.fir.kt

@@ -15,9 +15,11 @@ class C(p: Any, val v: Any) {
     // NB here we can use both 'T' (property type parameter) and 'p' (primary constructor parameter)
     val <T> List<T>.test3 by delegateFactory<T>(p)
 
-    val test4 get() { return <!UNRESOLVED_REFERENCE!>p<!> }
+    <!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>val test4<!> get() { return <!UNRESOLVED_REFERENCE!>p<!> }
 
-    var test5
+    <!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>var test5<!>
         get() { return <!UNRESOLVED_REFERENCE!>p<!> }
         set(nv) { <!UNRESOLVED_REFERENCE!>p<!>.let {} }
+
+    <!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>lateinit var test6<!>
 }

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/primaryConstructorParameter.kt

@@ -20,4 +20,6 @@ class C(p: Any, val v: Any) {
     <!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>var test5<!>
         get() { return <!UNRESOLVED_REFERENCE!>p<!> }
         set(nv) { <!UNRESOLVED_REFERENCE!>p<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>let<!> {} }
+
+    <!PROPERTY_WITH_NO_TYPE_NO_INITIALIZER!>lateinit var test6<!>
 }

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/primaryConstructorParameter.txt

@@ -8,6 +8,7 @@ public final class C {
     public final val test2: kotlin.Any
     public final val test4: [Error type: Return type for property test4 cannot be resolved]
     public final var test5: [Error type: Return type for property test5 cannot be resolved]
+    public final lateinit var test6: [Error type: Return type for property test6 cannot be resolved]
     public final val v: kotlin.Any
     public final val </*0*/ T> kotlin.collections.List<T>.test3: kotlin.String
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean