add fixes to change expected type when inference fails due to it (IDEA-162846)

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightMethodUtil.java

@@ -390,6 +390,7 @@ public class HighlightMethodUtil {
           if (highlightInfo != null) {
             registerMethodCallIntentions(highlightInfo, methodCall, list, resolveHelper);
             registerMethodReturnFixAction(highlightInfo, (MethodCandidateInfo)resolveResult, methodCall);
+            registerTargetTypeFixesBasedOnApplicabilityInference(methodCall, (MethodCandidateInfo)resolveResult, (PsiMethod)resolved, highlightInfo);
           }
         }
       }
@@ -430,6 +431,7 @@ public class HighlightMethodUtil {
           if (highlightInfo != null) {
             registerMethodCallIntentions(highlightInfo, methodCall, list, resolveHelper);
             registerMethodReturnFixAction(highlightInfo, candidateInfo, methodCall);
+            registerTargetTypeFixesBasedOnApplicabilityInference(methodCall, candidateInfo, resolvedMethod, highlightInfo);
           }
         }
         else {
@@ -472,6 +474,36 @@ public class HighlightMethodUtil {
     return highlightInfo;
   }
 
+  private static void registerTargetTypeFixesBasedOnApplicabilityInference(@NotNull PsiMethodCallExpression methodCall,
+                                                                           MethodCandidateInfo resolveResult,
+                                                                           PsiMethod resolved,
+                                                                           HighlightInfo highlightInfo) {
+    PsiElement parent = PsiUtil.skipParenthesizedExprUp(methodCall.getParent());
+    PsiVariable variable = null;
+    if (parent instanceof PsiVariable) {
+      variable = (PsiVariable)parent;
+    }
+    else if (parent instanceof PsiAssignmentExpression) {
+      PsiExpression lExpression = ((PsiAssignmentExpression)parent).getLExpression();
+      if (lExpression instanceof PsiReferenceExpression) {
+        PsiElement resolve = ((PsiReferenceExpression)lExpression).resolve();
+        if (resolve instanceof PsiVariable) {
+          variable = (PsiVariable)resolve;
+        }
+      }
+    }
+
+    if (variable != null) {
+      PsiType rType = methodCall.getType();
+      if (rType != null && !variable.getType().isAssignableFrom(rType)) {
+        PsiType expectedTypeByApplicabilityConstraints = resolveResult.getSubstitutor(false).substitute(resolved.getReturnType());
+        if (expectedTypeByApplicabilityConstraints != null && !expectedTypeByApplicabilityConstraints.equals(rType)) {
+          HighlightUtil.registerChangeVariableTypeFixes(variable, expectedTypeByApplicabilityConstraints, methodCall, highlightInfo);
+        }
+      }
+    }
+  }
+
   /* see also PsiReferenceExpressionImpl.hasValidQualifier() */
   @Nullable
   private static String checkStaticInterfaceMethodCallQualifier(PsiReferenceExpression ref, PsiElement scope, PsiClass containingClass) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/variableType/afterFailedInferenceDueToWrongExpectedType.java

@@ -0,0 +1,10 @@
+// "Change variable 'foo' type to 'java.util.List<java.lang.String>'" "true"
+
+import java.util.Arrays;
+import java.util.List;
+
+class MyClass {
+  void bar() {
+    List<String> foo = Arrays.asList("a");
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/variableType/afterFailedInferenceDueToWrongExpectedTypeAssignment.java

@@ -0,0 +1,11 @@
+// "Change variable 'foo' type to 'java.util.List<java.lang.String>'" "true"
+
+import java.util.Arrays;
+import java.util.List;
+
+class MyClass {
+  void bar() {
+    List<String> foo;
+    foo = (Arrays.asList("a"));
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/variableType/afterFailedInferenceDueToWrongExpectedTypeNotApplicable.java

@@ -0,0 +1,15 @@
+// "Change variable 'foo' type to 'java.lang.String'" "true"
+
+import java.util.List;
+import java.util.Set;
+
+class MyClass {
+  public static void sort(final List<String> list) {
+    String foo = (findStart(list));
+  }
+
+  private static <V> V findStart(List<V> result) {
+    return result.get(0);
+  }
+
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/variableType/beforeFailedInferenceDueToWrongExpectedType.java

@@ -0,0 +1,10 @@
+// "Change variable 'foo' type to 'java.util.List<java.lang.String>'" "true"
+
+import java.util.Arrays;
+import java.util.List;
+
+class MyClass {
+  void bar() {
+    String[] foo = Arrays.asList(<caret>"a");
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/variableType/beforeFailedInferenceDueToWrongExpectedTypeAssignment.java

@@ -0,0 +1,11 @@
+// "Change variable 'foo' type to 'java.util.List<java.lang.String>'" "true"
+
+import java.util.Arrays;
+import java.util.List;
+
+class MyClass {
+  void bar() {
+    String[] foo;
+    foo = (Arrays.asList(<caret>"a"));
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/variableType/beforeFailedInferenceDueToWrongExpectedTypeNotApplicable.java

@@ -0,0 +1,15 @@
+// "Change variable 'foo' type to 'java.lang.String'" "true"
+
+import java.util.List;
+import java.util.Set;
+
+class MyClass {
+  public static void sort(final List<String> list) {
+    Set<String> foo = (findStart(<caret>list));
+  }
+
+  private static <V> V findStart(List<V> result) {
+    return result.get(0);
+  }
+
+}