Return null if found similar element is the same as the original one

python/src/com/jetbrains/python/pyi/PyiUtil.java

@@ -184,11 +184,13 @@ public class PyiUtil {
           final PyClassLikeType instanceType = classType.toInstance();
           final List<? extends RatedResolveResult> resolveResults = instanceType.resolveMember(name, null, AccessDirection.READ,
                                                                                                PyResolveContext.noImplicits(), false);
-          return takeTopPriorityElement(resolveResults);
+          final PsiElement result = takeTopPriorityElement(resolveResults);
+          return result == element ? null : result;
         }
       }
       else if (originalOwner instanceof PyFile) {
-        return takeTopPriorityElement(((PyFile)originalOwner).multiResolveName(name));
+        final PsiElement result = takeTopPriorityElement(((PyFile)originalOwner).multiResolveName(name));
+        return result == element ? null : result;
       }
     }
     return null;

python/testData/pyi/lineMarkers/AnotherTypeSimilarForFunctionStub/b.py

@@ -0,0 +1 @@
+foo = None

python/testData/pyi/lineMarkers/AnotherTypeSimilarForFunctionStub/b.pyi

@@ -0,0 +1,2 @@
+def foo():
+    pass

python/testData/pyi/lineMarkers/AnotherTypeSimilarForMethodStub/b.py

@@ -0,0 +1,2 @@
+class B:
+    bar = None

python/testData/pyi/lineMarkers/AnotherTypeSimilarForMethodStub/b.pyi

@@ -0,0 +1,3 @@
+class B:
+    def bar(self):
+        pass

python/testData/pyi/lineMarkers/AnotherTypeSimilarForRuntimeFunction/a.py

@@ -0,0 +1,2 @@
+def function():
+    pass

python/testData/pyi/lineMarkers/AnotherTypeSimilarForRuntimeFunction/a.pyi

@@ -0,0 +1 @@
+function = None

python/testData/pyi/lineMarkers/AnotherTypeSimilarForRuntimeMethod/a.py

@@ -0,0 +1,3 @@
+class A:
+    def method(self):
+        pass

python/testData/pyi/lineMarkers/AnotherTypeSimilarForRuntimeMethod/a.pyi

@@ -0,0 +1,2 @@
+class A:
+    method = None

python/testData/pyi/lineMarkers/NoSimilarClassForMethodStub/b.pyi

@@ -0,0 +1,3 @@
+class B:
+    def bar(self):
+        pass

python/testData/pyi/lineMarkers/NoSimilarClassForRuntimeMethod/a.py

@@ -0,0 +1,3 @@
+class A:
+    def method(self):
+        pass

python/testData/pyi/lineMarkers/NoSimilarForFunctionStub/b.pyi

@@ -0,0 +1,2 @@
+def foo():
+    pass

python/testData/pyi/lineMarkers/NoSimilarForMethodStub/b.py

@@ -0,0 +1,2 @@
+class B:
+    pass

python/testData/pyi/lineMarkers/NoSimilarForMethodStub/b.pyi

@@ -0,0 +1,3 @@
+class B:
+    def bar(self):
+        pass

python/testData/pyi/lineMarkers/NoSimilarForRuntimeFunction/a.py

@@ -0,0 +1,2 @@
+def function():
+    pass

python/testData/pyi/lineMarkers/NoSimilarForRuntimeMethod/a.py

@@ -0,0 +1,3 @@
+class A:
+    def method(self):
+        pass

python/testData/pyi/lineMarkers/NoSimilarForRuntimeMethod/a.pyi

@@ -0,0 +1,2 @@
+class A:
+    pass

python/testData/pyi/lineMarkers/NoSimilarModuleForFunctionStub/b.pyi

@@ -0,0 +1,2 @@
+def foo():
+    pass

python/testData/pyi/lineMarkers/NoSimilarModuleForRuntimeFunction/a.py

@@ -0,0 +1,2 @@
+def function():
+    pass

python/testData/pyi/lineMarkers/OverloadsAndImplementationInPyFile/a.py

@@ -0,0 +1,14 @@
+from typing import overload
+
+
+class B:
+    @overload
+    def baz(self, v: str):
+        pass
+
+    @overload
+    def baz(self, v: int):
+        pass
+
+    def baz(self, v):
+        pass

python/testData/pyi/lineMarkers/SimilarForFunctionStub/b.py

@@ -0,0 +1,2 @@
+def foo():
+    pass

python/testData/pyi/lineMarkers/SimilarForFunctionStub/b.pyi

@@ -0,0 +1,2 @@
+def foo():
+    pass

python/testData/pyi/lineMarkers/SimilarForMethodStub/b.py

@@ -0,0 +1,3 @@
+class B:
+    def bar(self):
+        pass

python/testData/pyi/lineMarkers/SimilarForMethodStub/b.pyi

@@ -0,0 +1,3 @@
+class B:
+    def bar(self):
+        pass

python/testData/pyi/lineMarkers/SimilarForRuntimeFunction/a.py

@@ -0,0 +1,2 @@
+def function():
+    pass

python/testData/pyi/lineMarkers/SimilarForRuntimeFunction/a.pyi

@@ -0,0 +1,2 @@
+def function():
+    pass

python/testData/pyi/lineMarkers/SimilarForRuntimeMethod/a.py

@@ -0,0 +1,3 @@
+class A:
+    def method(self):
+        pass

python/testData/pyi/lineMarkers/SimilarForRuntimeMethod/a.pyi

@@ -0,0 +1,3 @@
+class A:
+    def method(self):
+        pass

python/testSrc/com/jetbrains/python/pyi/PyiRelatedItemLineMarkerTest.kt

@@ -0,0 +1,113 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.python.pyi
+
+import com.intellij.codeInsight.daemon.LineMarkerInfo
+import com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerImpl
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiNameIdentifierOwner
+import com.intellij.psi.util.PsiTreeUtil
+import com.jetbrains.python.fixtures.PyTestCase
+import com.jetbrains.python.psi.PyFunction
+
+class PyiRelatedItemLineMarkerTest : PyTestCase() {
+
+  fun testOverloadsAndImplementationInPyFile() {
+    assertNoMarker("baz", false)
+  }
+
+  // runtime -> stub
+
+  fun testNoSimilarClassForRuntimeMethod() {
+    assertNoMarker("method", false)
+  }
+
+  fun testNoSimilarForRuntimeMethod() {
+    assertNoMarker("method", false)
+  }
+
+  fun testSimilarForRuntimeMethod() {
+    assertMarker("method", false)
+  }
+
+  fun testAnotherTypeSimilarForRuntimeMethod() {
+    assertMarker("method", false)
+  }
+
+  fun testNoSimilarModuleForRuntimeFunction() {
+    assertNoMarker("function", false)
+  }
+
+  fun testNoSimilarForRuntimeFunction() {
+    assertNoMarker("function", false)
+  }
+
+  fun testSimilarForRuntimeFunction() {
+    assertMarker("function", false)
+  }
+
+  fun testAnotherTypeSimilarForRuntimeFunction() {
+    assertMarker("function", false)
+  }
+
+  // stub -> runtime
+
+  fun testNoSimilarClassForMethodStub() {
+    assertNoMarker("bar", true)
+  }
+
+  fun testNoSimilarForMethodStub() {
+    assertNoMarker("bar", true)
+  }
+
+  fun testSimilarForMethodStub() {
+    assertMarker("bar", true)
+  }
+
+  fun testAnotherTypeSimilarForMethodStub() {
+    assertMarker("bar", true)
+  }
+
+  fun testNoSimilarModuleForFunctionStub() {
+    assertNoMarker("foo", true)
+  }
+
+  fun testNoSimilarForFunctionStub() {
+    assertNoMarker("foo", true)
+  }
+
+  fun testSimilarForFunctionStub() {
+    assertMarker("foo", true)
+  }
+
+  fun testAnotherTypeSimilarForFunctionStub() {
+    assertMarker("foo", true)
+  }
+
+  override fun getTestDataPath(): String {
+    return super.getTestDataPath() + "/pyi/lineMarkers"
+  }
+
+  private fun assertMarker(elementName: String, pyi: Boolean) {
+    val expectedTooltip = if (pyi) "Stub for item in b.py" else "Has stub item in a.pyi"
+    assertEquals(expectedTooltip, getMarkers(elementName, pyi).singleOrNull()?.lineMarkerTooltip)
+  }
+
+  private fun assertNoMarker(elementName: String, pyi: Boolean) {
+    assertEmpty(getMarkers(elementName, pyi))
+  }
+
+  private fun getMarkers(elementName: String, pyi: Boolean): List<LineMarkerInfo<PsiElement>> {
+    myFixture.copyDirectoryToProject(getTestName(false), "")
+    myFixture.configureByFile(if (pyi) "b.pyi" else "a.py")
+
+    val functions = PsiTreeUtil.findChildrenOfType(myFixture.file, PyFunction::class.java)
+    functions.forEach { assertEquals(elementName, it.name) }
+    assertNotEmpty(functions)
+
+    myFixture.doHighlighting()
+
+    return DaemonCodeAnalyzerImpl
+      .getLineMarkers(myFixture.editor.document, myFixture.project)
+      .filter { PsiTreeUtil.getParentOfType(it.element, PsiNameIdentifierOwner::class.java)?.name == elementName }
+  }
+}