IDEA-133514 (Malformed format string inspection doesn't seem to understand Java 8's java.time classes)

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

@@ -260,7 +260,8 @@ class FormatDecode {
       return PsiType.LONG.equals(type) ||
              CommonClassNames.JAVA_LANG_LONG.equals(text) ||
              InheritanceUtil.isInheritor(type, CommonClassNames.JAVA_UTIL_DATE) ||
-             InheritanceUtil.isInheritor(type, CommonClassNames.JAVA_UTIL_CALENDAR);
+             InheritanceUtil.isInheritor(type, CommonClassNames.JAVA_UTIL_CALENDAR) ||
+             InheritanceUtil.isInheritor(type, "java.time.temporal.TemporalAccessor");
     }
   }
 

plugins/InspectionGadgets/test/com/siyeh/igtest/bugs/malformed_format_string/MalformedFormatString.java

@@ -89,5 +89,6 @@ public class MalformedFormatString {
     void goodStrings() {
         String.format("%-B", true); // left justify flag
         String.format("%,d", 34567890);
+        System.out.printf("%tF %n", java.time.ZonedDateTime.now()); // java.time.temporal.TemporalAccessor, new in Java 8
     }
 }

plugins/InspectionGadgets/testsrc/com/siyeh/ig/bugs/MalformedFormatStringInspectionTest.java

@@ -18,4 +18,52 @@ public class MalformedFormatStringInspectionTest extends LightInspectionTestCase
     inspection.methodNames.add("d");
     return inspection;
   }
+
+  @Override
+  protected String[] getEnvironmentClasses() {
+    return new String[] {
+      "package java.time.temporal;\n" +
+      "public interface TemporalAccessor {\n" +
+      "    boolean isSupported(TemporalField field);\n" +
+      "    default ValueRange range(TemporalField field) {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "    default int get(TemporalField field) {\n" +
+      "        return 0;\n" +
+      "    }\n" +
+      "    long getLong(TemporalField field);\n" +
+      "    default <R> R query(TemporalQuery<R> query) {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "}",
+
+      "package java.time.temporal;\n" +
+      "public interface Temporal extends TemporalAccessor {\n" +
+      "    boolean isSupported(TemporalUnit unit);\n" +
+      "    default Temporal with(TemporalAdjuster adjuster) {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "    Temporal with(TemporalField field, long newValue);\n" +
+      "    default Temporal plus(TemporalAmount amount) {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "    Temporal plus(long amountToAdd, TemporalUnit unit);\n" +
+      "    default Temporal minus(TemporalAmount amount) {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "    default Temporal minus(long amountToSubtract, TemporalUnit unit) {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "    long until(Temporal endExclusive, TemporalUnit unit);\n" +
+      "}",
+
+      "package java.time;\n" +
+      "import java.time.temporal.Temporal;\n" +
+      "public abstract class ZonedDateTime implements Temporal {\n" +
+      "    public static ZonedDateTime now() {\n" +
+      "        return null;\n" +
+      "    }\n" +
+      "}"
+    };
+  }
 }