KTIJ-26103 [Analysis API] Ignore implicit dispatch receivers in Reference Shortener

Calls to extension functions imported from objects have implicit
dispatch receivers, but those receivers are not present in the code
and should not be analyzed by the shortener

^KTIJ-26103 Fixed

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/FirUtils.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.analysis.api.fir
 
+import org.jetbrains.kotlin.KtFakeSourceElementKind
 import org.jetbrains.kotlin.analysis.api.annotations.KtAnnotationApplicationInfo
 import org.jetbrains.kotlin.analysis.api.annotations.KtAnnotationApplicationWithArgumentsInfo
 import org.jetbrains.kotlin.analysis.api.annotations.KtNamedAnnotationValue
@@ -17,6 +18,7 @@ import org.jetbrains.kotlin.fir.diagnostics.ConeDiagnostic
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
 import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.expressions.FirResolvedQualifier
 import org.jetbrains.kotlin.fir.expressions.arguments
 import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
@@ -94,3 +96,21 @@ internal fun FirAnnotation.toKtAnnotationInfo(
     isCallWithArguments = this is FirAnnotationCall && arguments.isNotEmpty(),
     index = index,
 )
+
+/**
+ * Implicit dispatch receiver is present when an extension function declared in object
+ * is imported somewhere else and used without directly referencing the object instance
+ * itself:
+ *
+ * ```kt
+ * import Foo.bar
+ *
+ * object Foo { fun String.bar() {} }
+ *
+ * fun usage() {
+ *   "hello".bar() // this call has implicit 'Foo' dispatch receiver
+ * }
+ * ```
+ */
+internal val FirResolvedQualifier.isImplicitDispatchReceiver: Boolean
+    get() = source?.kind == KtFakeSourceElementKind.ImplicitReceiver

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirImportOptimizer.kt

@@ -5,11 +5,11 @@
 
 package org.jetbrains.kotlin.analysis.api.fir.components
 
-import org.jetbrains.kotlin.KtFakeSourceElementKind
 import org.jetbrains.kotlin.KtRealSourceElementKind
 import org.jetbrains.kotlin.analysis.api.components.KtImportOptimizer
 import org.jetbrains.kotlin.analysis.api.components.KtImportOptimizerResult
 import org.jetbrains.kotlin.analysis.api.fir.getCandidateSymbols
+import org.jetbrains.kotlin.analysis.api.fir.isImplicitDispatchReceiver
 import org.jetbrains.kotlin.analysis.api.fir.utils.FirBodyReanalyzingVisitorVoid
 import org.jetbrains.kotlin.analysis.api.fir.utils.computeImportableName
 import org.jetbrains.kotlin.analysis.api.lifetime.KtLifetimeToken
@@ -274,7 +274,7 @@ internal class KtFirImportOptimizer(
                 val dispatchReceiver = dispatchReceiver
                 if (
                     dispatchReceiver !is FirResolvedQualifier ||
-                    dispatchReceiver.source?.kind != KtFakeSourceElementKind.ImplicitReceiver
+                    !dispatchReceiver.isImplicitDispatchReceiver
                 ) {
                     return null
                 }

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirReferenceShortener.kt

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.analysis.api.components.ShortenCommand
 import org.jetbrains.kotlin.analysis.api.components.ShortenOption
 import org.jetbrains.kotlin.analysis.api.fir.KtFirAnalysisSession
 import org.jetbrains.kotlin.analysis.api.fir.components.ElementsToShortenCollector.PartialOrderOfScope.Companion.toPartialOrder
+import org.jetbrains.kotlin.analysis.api.fir.isImplicitDispatchReceiver
 import org.jetbrains.kotlin.analysis.api.fir.utils.FirBodyReanalyzingVisitorVoid
 import org.jetbrains.kotlin.analysis.api.fir.utils.computeImportableName
 import org.jetbrains.kotlin.analysis.api.lifetime.KtLifetimeToken
@@ -427,6 +428,8 @@ private class ElementsToShortenCollector(
     }
 
     private fun processTypeQualifier(resolvedQualifier: FirResolvedQualifier) {
+        if (resolvedQualifier.isImplicitDispatchReceiver) return
+
         val wholeClassQualifier = resolvedQualifier.classId ?: return
         val qualifierPsi = resolvedQualifier.psi ?: return
         if (!qualifierPsi.textRange.intersects(selection)) return

analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/references/FirIdeNormalAnalysisSourceModuleReferenceShortenerTestGenerated.java

@@ -232,6 +232,12 @@ public class FirIdeNormalAnalysisSourceModuleReferenceShortenerTestGenerated ext
         runTest("analysis/analysis-api/testData/components/referenceShortener/referenceShortener/enumEntryInitUsesCompanion2.kt");
     }
 
+    @Test
+    @TestMetadata("extensionFromObject.kt")
+    public void testExtensionFromObject() throws Exception {
+        runTest("analysis/analysis-api/testData/components/referenceShortener/referenceShortener/extensionFromObject.kt");
+    }
+
     @Test
     @TestMetadata("multipleImport.kt")
     public void testMultipleImport() throws Exception {

analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/references/FirStandaloneNormalAnalysisSourceModuleReferenceShortenerTestGenerated.java

@@ -232,6 +232,12 @@ public class FirStandaloneNormalAnalysisSourceModuleReferenceShortenerTestGenera
         runTest("analysis/analysis-api/testData/components/referenceShortener/referenceShortener/enumEntryInitUsesCompanion2.kt");
     }
 
+    @Test
+    @TestMetadata("extensionFromObject.kt")
+    public void testExtensionFromObject() throws Exception {
+        runTest("analysis/analysis-api/testData/components/referenceShortener/referenceShortener/extensionFromObject.kt");
+    }
+
     @Test
     @TestMetadata("multipleImport.kt")
     public void testMultipleImport() throws Exception {

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/extensionFromObject.kt

@@ -0,0 +1,15 @@
+// FILE: main.kt
+package test
+
+import dependency.Bar.extFun
+
+fun usage(str: String) {
+    <expr>str.extFun()</expr>
+}
+
+// FILE: dependency.kt
+package dependency
+
+object Bar {
+    fun String.extFun() {}
+}

analysis/analysis-api/testData/components/referenceShortener/referenceShortener/extensionFromObject.txt

@@ -0,0 +1,5 @@
+Before shortening: str.extFun()
+with DO_NOT_SHORTEN:
+with SHORTEN_IF_ALREADY_IMPORTED:
+with SHORTEN_AND_IMPORT:
+with SHORTEN_AND_STAR_IMPORT: