{"record":{"id":"93487b9460a8ae36","repo":"dotnet/reactive","slug":"source2","errorCode":null,"errorMessage":"source2","messagePattern":"source2","errorType":"validation","errorClass":"ArgumentNullException","httpStatus":null,"severity":"error","filePath":"Rx.NET/Source/src/System.Reactive/Linq/Observable.Multiple.Zip.cs","lineNumber":858,"sourceCode":"        /// <param name=\"source9\">Ninth observable source.</param>\n        /// <param name=\"source10\">Tenth observable source.</param>\n        /// <param name=\"source11\">Eleventh observable source.</param>\n        /// <param name=\"source12\">Twelfth observable source.</param>\n        /// <param name=\"source13\">Thirteenth observable source.</param>\n        /// <param name=\"source14\">Fourteenth observable source.</param>\n        /// <param name=\"resultSelector\">Function to invoke for each series of elements at corresponding indexes in the sources.</param>\n        /// <returns>An observable sequence containing the result of combining elements of the sources using the specified result selector function.</returns>\n        /// <exception cref=\"ArgumentNullException\"><paramref name=\"source1\"/> or <paramref name=\"source2\"/> or <paramref name=\"source3\"/> or <paramref name=\"source4\"/> or <paramref name=\"source5\"/> or <paramref name=\"source6\"/> or <paramref name=\"source7\"/> or <paramref name=\"source8\"/> or <paramref name=\"source9\"/> or <paramref name=\"source10\"/> or <paramref name=\"source11\"/> or <paramref name=\"source12\"/> or <paramref name=\"source13\"/> or <paramref name=\"source14\"/> or <paramref name=\"resultSelector\"/> is null.</exception>\n        public static IObservable<TResult> Zip<TSource1, TSource2, TSource3, TSource4, TSource5, TSource6, TSource7, TSource8, TSource9, TSource10, TSource11, TSource12, TSource13, TSource14, TResult>(this IObservable<TSource1> source1, IObservable<TSource2> source2, IObservable<TSource3> source3, IObservable<TSource4> source4, IObservable<TSource5> source5, IObservable<TSource6> source6, IObservable<TSource7> source7, IObservable<TSource8> source8, IObservable<TSource9> source9, IObservable<TSource10> source10, IObservable<TSource11> source11, IObservable<TSource12> source12, IObservable<TSource13> source13, IObservable<TSource14> source14, Func<TSource1, TSource2, TSource3, TSource4, TSource5, TSource6, TSource7, TSource8, TSource9, TSource10, TSource11, TSource12, TSource13, TSource14, TResult> resultSelector)\n        {\n            if (source1 == null)\n            {\n                throw new ArgumentNullException(nameof(source1));\n            }\n\n            if (source2 == null)\n            {\n                throw new ArgumentNullException(nameof(source2));\n            }\n\n            if (source3 == null)\n            {\n                throw new ArgumentNullException(nameof(source3));\n            }\n\n            if (source4 == null)\n            {\n                throw new ArgumentNullException(nameof(source4));\n            }\n\n            if (source5 == null)\n            {\n                throw new ArgumentNullException(nameof(source5));\n            }\n\n            if (source6 == null)","sourceCodeStart":840,"sourceCodeEnd":876,"githubUrl":"https://github.com/dotnet/reactive/blob/94b5d5ab912789f5abe9a72138a25bbd716fe59c/Rx.NET/Source/src/System.Reactive/Linq/Observable.Multiple.Zip.cs#L840-L876","documentation":"In the 14-source Zip overload, the second sequence (source2) is validated to be non-null at line 858, right after source1. Zipping cannot proceed if any of the 14 input streams is null, so Rx throws ArgumentNullException with parameter name 'source2' at call time.","triggerScenarios":"Calling the 14-argument Observable.Zip with null in the second position while source1 and the rest are valid observables.","commonSituations":"A null returned from a service/stream factory for the second feed, a misordered argument list in the long 15-parameter call, or an optional stream passed as null instead of Observable.Empty.","solutions":["Replace the null in the second argument position with Observable.Empty<TSource2>().","Fix the upstream producer that returned null for source2.","Add explicit null checks for each source before calling Zip.","Re-verify the argument ordering of all 14 sources in the call."],"exampleFix":"// before\nvar zipped = Observable.Zip(s1, null, s3, ..., s14, selector);\n// after\nvar zipped = Observable.Zip(s1, s2 ?? Observable.Empty<TSource2>(), s3, ..., s14, selector);","handlingStrategy":"validation","validationCode":"if (source2 == null) throw new ArgumentNullException(nameof(source2));","typeGuard":"static IObservable<T> NonNull<T>(IObservable<T> s) => s ?? Observable.Empty<T>();","tryCatchPattern":"try { var zipped = Observable.Zip(source1, source2, ...); } catch (ArgumentNullException ex) when (ex.ParamName == \"source2\") { /* substitute default source or abort */ }","preventionTips":["Validate each argument in order before calling multi-source Zip.","Prefer Observable.Empty<T>() over null for optional streams.","Keep long Zip call sites behind a checked helper to catch nulls once."],"tags":["rx","null-argument","argument-validation"],"backgroundTag":"null-argument","analyzedSha":"94b5d5ab912789f5abe9a72138a25bbd716fe59c","analyzedAt":"2026-09-15T02:26:24.759Z","contentChangedAt":"2026-09-15T02:26:24.759Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}