fixed PY-3094 Intention to transform conditional expression into if/else statement

python/src/META-INF/python-plugin-common.xml

@@ -189,6 +189,11 @@
       <category>Python</category>
     </intentionAction>
 
+    <intentionAction>
+      <className>com.jetbrains.python.codeInsight.intentions.PyTransformConditionalExpressionIntention</className>
+      <category>Python</category>
+    </intentionAction>
+
     <stubElementTypeHolder class="com.jetbrains.python.PyElementTypes"/>
     <inspectionToolProvider implementation="com.jetbrains.python.inspections.PythonInspectionToolProvider"/>
 
@@ -432,6 +437,7 @@
     <annotator language="Locale" implementationClass="com.jetbrains.django.localization.validation.LocaleAnnotatingVisitor"/>
     <quoteHandler fileType="Locale" className="com.jetbrains.django.localization.editor.LocaleQuoteHandler"/>
     <problemFileHighlightFilter implementation="com.jetbrains.django.localization.LocaleProblemFileHighlightFilter"/>
+    <!--<fileEditorProvider implementation="com.jetbrains.django.localization.editor.LocaleFileEditorProvider"/>-->
   </extensions>
 
   <extensionPoints>

python/src/com/jetbrains/python/PyBundle.properties

@@ -155,6 +155,9 @@ INTN.convert.variadic.param=Convert from variadic to normal parameter(s)
 # PyConvertTripleQuotedStringIntention
 INTN.triple.quoted.string=Convert triple-quoted string to single-quoted string
 
+# PyTransformConditionalExpressionIntention
+INTN.transform.into.if.else.statement=Transform conditional expression into if/else statement
+
 # Conflict checker
 CONFLICT.name.$0.obscured=Name ''{0}'' obscured by local definitions
 CONFLICT.name.$0.obscured.cannot.convert=Name ''{0}'' obscured. Cannot convert.

python/src/com/jetbrains/python/codeInsight/intentions/PyTransformConditionalExpressionIntention.java

@@ -0,0 +1,65 @@
+package com.jetbrains.python.codeInsight.intentions;
+
+import com.intellij.codeInsight.intention.impl.BaseIntentionAction;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.IncorrectOperationException;
+import com.jetbrains.python.PyBundle;
+import com.jetbrains.python.psi.*;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: catherine
+ * Intention to transform conditional expression into if/else statement
+ * For instance,
+ *
+ * x = a if cond else b
+ *
+ * into:
+ *
+ * if cond:
+ *    x = a
+ * else:
+ *    x = b
+ */
+public class PyTransformConditionalExpressionIntention extends BaseIntentionAction {
+  @NotNull
+  public String getFamilyName() {
+    return PyBundle.message("INTN.transform.into.if.else.statement");
+  }
+
+  @NotNull
+  public String getText() {
+    return PyBundle.message("INTN.transform.into.if.else.statement");
+  }
+
+  public boolean isAvailable(@NotNull Project project, Editor editor, PsiFile file) {
+    PyAssignmentStatement expression =
+      PsiTreeUtil.getParentOfType(file.findElementAt(editor.getCaretModel().getOffset()), PyAssignmentStatement.class);
+    if (expression != null && expression.getAssignedValue() instanceof PyConditionalExpression) {
+      return true;
+    }
+    return false;
+  }
+
+  public void invoke(@NotNull Project project, Editor editor, PsiFile file) throws IncorrectOperationException {
+    PyAssignmentStatement assignmentStatement =
+          PsiTreeUtil.getParentOfType(file.findElementAt(editor.getCaretModel().getOffset()), PyAssignmentStatement.class);
+    assert assignmentStatement != null;
+    PyConditionalExpression expression =
+      (PyConditionalExpression)assignmentStatement.getAssignedValue();
+    assert expression != null;
+    String condition = expression.getCondition().getText();
+    String truePart = expression.getTruePart().getText();
+    String falsePart = expression.getFalsePart().getText();
+    String target = assignmentStatement.getLeftHandSideExpression().getText();
+
+    PyElementGenerator elementGenerator = PyElementGenerator.getInstance(project);
+    String text = "if " + condition + ":\n\t" + target + " = " + truePart + "\nelse:\n\t" + target + " = " + falsePart;
+    PyIfStatement ifStatement = elementGenerator.createFromText(LanguageLevel.forElement(expression), PyIfStatement.class, text);
+    assignmentStatement.replace(ifStatement);
+  }
+
+}

python/testData/intentions/afterTransformConditionalExpression.py

@@ -0,0 +1,4 @@
+if cond:
+    x = a
+else:
+    x = b

python/testData/intentions/beforeTransformConditionalExpression.py

@@ -0,0 +1 @@
+x = a if <caret>cond else b

python/testSrc/com/jetbrains/python/PyIntentionTest.java

@@ -164,4 +164,8 @@ public class PyIntentionTest extends PyLightFixtureTestCase {
   public void testConvertTripleQuotedString() { //PY-2697
     doTest(PyBundle.message("INTN.triple.quoted.string"));
   }
+
+  public void testTransformConditionalExpression() { //PY-3094
+    doTest(PyBundle.message("INTN.transform.into.if.else.statement"));
+  }
 }