IDEA-181754 Result of 'xyz()' not thrown: do not report on always failing methods

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/bugs/ThrowableNotThrownInspection.java

@@ -15,6 +15,9 @@
  */
 package com.siyeh.ig.bugs;
 
+import com.intellij.codeInspection.dataFlow.ControlFlowAnalyzer;
+import com.intellij.codeInspection.dataFlow.MethodContract;
+import com.intellij.codeInspection.dataFlow.StandardMethodContract;
 import com.intellij.psi.*;
 import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.psi.util.InheritanceUtil;
@@ -28,6 +31,8 @@ import com.siyeh.ig.psiutils.ParenthesesUtils;
 import com.siyeh.ig.psiutils.TypeUtils;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.List;
+
 public class ThrowableNotThrownInspection extends BaseInspection {
 
   @Override
@@ -105,8 +110,12 @@ public class ThrowableNotThrownInspection extends BaseInspection {
           InheritanceUtil.isInheritor(containingClass, CommonClassNames.JAVA_LANG_THROWABLE)) {
         return;
       }
-      if ("propagate".equals(method.getName()) && "com.google.common.base.Throwables".equals(containingClass.getQualifiedName())) {
-        return;
+      List<StandardMethodContract> contracts = ControlFlowAnalyzer.getMethodContracts(method);
+      if (contracts.size() == 1) {
+        StandardMethodContract contract = contracts.get(0);
+        if (contract.isTrivial() && contract.getReturnValue() == MethodContract.ValueConstraint.THROW_EXCEPTION) {
+          return;
+        }
       }
       registerMethodCallError(expression, expression);
     }

plugins/InspectionGadgets/test/com/siyeh/igtest/bugs/throwable_result_of_method_call_ignored/ThrowableResultOfMethodCallIgnored.java

@@ -126,4 +126,21 @@ class Throwables {
         String message = cause.getMessage();
         System.out.println("message = " + message);
     }
+}
+
+class FailTest {
+    static RuntimeException fail() {
+        throw new RuntimeException();
+    }
+
+    void testThrow(int x) {
+        if(x < 0) {
+            throw fail();
+        }
+    }
+    void testNoThrow(int x) {
+        if(x < 0) {
+            fail();
+        }
+    }
 }