IDEA-209951 Inspection to detect when collection is accidentally passed as vararg and will be wrapped into one-element array

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/iterableUsedAsVararg/afterError.java

@@ -0,0 +1,20 @@
+// "Call 'toArray(new String[0])'" "true"
+import java.util.List;
+import java.util.Objects;
+
+class Test {
+  static <T> boolean contains(T needle, T... haystack) {
+    for (final T t : haystack) {
+      if (Objects.equals(t, needle)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  void use(List<String> list, String s) {
+    if (contains(s, list.toArray(new String[0]))) {
+
+    }
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/iterableUsedAsVararg/beforeError.java

@@ -0,0 +1,20 @@
+// "Call 'toArray(new String[0])'" "true"
+import java.util.List;
+import java.util.Objects;
+
+class Test {
+  static <T> boolean contains(T needle, T... haystack) {
+    for (final T t : haystack) {
+      if (Objects.equals(t, needle)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  void use(List<String> list, String s) {
+    if (contains(s, <caret>list)) {
+
+    }
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/iterableUsedAsVararg/beforeOk.java

@@ -0,0 +1,20 @@
+// "Call 'toArray(new String[0])'" "false"
+import java.util.List;
+import java.util.Objects;
+
+class Test {
+  static <T> boolean contains(T needle, T... haystack) {
+    for (final T t : haystack) {
+      if (Objects.equals(t, needle)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  void useOk(List<String> list, List<String> s) {
+    if (contains(s, <caret>list)) {
+
+    }
+  }
+}