PY-19399 Prohibit intention "Convert collection to set" for empty collections

since there is no literal for empty set in Python.

diff --git a/python/src/com/jetbrains/python/codeInsight/intentions/PyBaseConvertCollectionLiteralIntention.java b/python/src/com/jetbrains/python/codeInsight/intentions/PyBaseConvertCollectionLiteralIntention.java
index d6dd06ae2709329b0fc1d99dc8c9fd81684b939a..db243d24b447b3b7fd484b8ab3c5be897c9a932a 100644 (file)
--- a/python/src/com/jetbrains/python/codeInsight/intentions/PyBaseConvertCollectionLiteralIntention.java
+++ b/python/src/com/jetbrains/python/codeInsight/intentions/PyBaseConvertCollectionLiteralIntention.java
@@ -82,7 +82,7 @@ public abstract class PyBaseConvertCollectionLiteralIntention extends BaseIntent
     return isAvailableForCollection(literal);
   }
 
-  protected boolean isAvailableForCollection(PySequenceExpression literal) {
+  protected boolean isAvailableForCollection(@NotNull PySequenceExpression literal) {
     return true;
   }
 

diff --git a/python/src/com/jetbrains/python/codeInsight/intentions/PyConvertLiteralToSetIntention.java b/python/src/com/jetbrains/python/codeInsight/intentions/PyConvertLiteralToSetIntention.java
index 0f21128c657b642d400e8d3c25b685c43f52c17e..5f18663024ad57664cb33e689f48420b35223a87 100644 (file)
--- a/python/src/com/jetbrains/python/codeInsight/intentions/PyConvertLiteralToSetIntention.java
+++ b/python/src/com/jetbrains/python/codeInsight/intentions/PyConvertLiteralToSetIntention.java
@@ -15,9 +15,11 @@
  */
 package com.jetbrains.python.codeInsight.intentions;
 
-import com.intellij.openapi.util.Condition;
 import com.intellij.util.containers.ContainerUtil;
-import com.jetbrains.python.psi.*;
+import com.jetbrains.python.psi.LanguageLevel;
+import com.jetbrains.python.psi.PySequenceExpression;
+import com.jetbrains.python.psi.PySetLiteralExpression;
+import com.jetbrains.python.psi.PyTargetExpression;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -29,16 +31,11 @@ public class PyConvertLiteralToSetIntention extends PyBaseConvertCollectionLiter
   }
 
   @Override
-  protected boolean isAvailableForCollection(PySequenceExpression literal) {
-    return LanguageLevel.forElement(literal).isAtLeast(LanguageLevel.PYTHON27) && !isInTargetPosition(literal);
+  protected boolean isAvailableForCollection(@NotNull PySequenceExpression literal) {
+    return !literal.isEmpty() && LanguageLevel.forElement(literal).isAtLeast(LanguageLevel.PYTHON27) && !isInTargetPosition(literal);
   }
 
-  private static boolean isInTargetPosition(@NotNull final PySequenceExpression sequenceLiteral) {
-    return ContainerUtil.exists(sequenceLiteral.getElements(), new Condition<PyExpression>() {
-      @Override
-      public boolean value(PyExpression expression) {
-        return expression instanceof PyTargetExpression;
-      }
-    });
+  private static boolean isInTargetPosition(@NotNull PySequenceExpression sequenceLiteral) {
+    return ContainerUtil.exists(sequenceLiteral.getElements(), expression -> expression instanceof PyTargetExpression);
   }
 }

diff --git a/python/testData/intentions/PyConvertCollectionLiteralIntentionTest/cannotConvertEmptyListToSet.py b/python/testData/intentions/PyConvertCollectionLiteralIntentionTest/cannotConvertEmptyListToSet.py
new file mode 100644 (file)
index 0000000..646916b
--- /dev/null
+++ b/python/testData/intentions/PyConvertCollectionLiteralIntentionTest/cannotConvertEmptyListToSet.py
@@ -0,0 +1 @@
+[<caret>]
\ No newline at end of file

diff --git a/python/testData/intentions/PyConvertCollectionLiteralIntentionTest/cannotConvertEmptyTupleToSet.py b/python/testData/intentions/PyConvertCollectionLiteralIntentionTest/cannotConvertEmptyTupleToSet.py
new file mode 100644 (file)
index 0000000..bd27bb5
--- /dev/null
+++ b/python/testData/intentions/PyConvertCollectionLiteralIntentionTest/cannotConvertEmptyTupleToSet.py
@@ -0,0 +1 @@
+(<caret>)
\ No newline at end of file

diff --git a/python/testSrc/com/jetbrains/python/intentions/PyConvertCollectionLiteralIntentionTest.java b/python/testSrc/com/jetbrains/python/intentions/PyConvertCollectionLiteralIntentionTest.java
index ba2211fe2b5898ebbdce92aa18d7c1ecdd3304f1..5bbc03d56b42e043cc740d8db56247a1d7417eb9 100644 (file)
--- a/python/testSrc/com/jetbrains/python/intentions/PyConvertCollectionLiteralIntentionTest.java
+++ b/python/testSrc/com/jetbrains/python/intentions/PyConvertCollectionLiteralIntentionTest.java
@@ -143,4 +143,14 @@ public class PyConvertCollectionLiteralIntentionTest extends PyIntentionTestCase
   public void testConvertOneElementTupleWithCommentToList() {
     doIntentionTest(CONVERT_TUPLE_TO_LIST);
   }
+
+  // PY-19399
+  public void testCannotConvertEmptyTupleToSet() {
+    doNegativeTest(CONVERT_TUPLE_TO_SET);
+  }
+  
+  // PY-19399
+  public void testCannotConvertEmptyListToSet() {
+    doNegativeTest(CONVERT_LIST_TO_SET);
+  }
 }