stride3d/stride · error · ArgumentNullException

fromText

Error message

fromText

What it means

The string-based Deserialize overload throws ArgumentNullException("fromText") when the YAML text passed in is null. This is an up-front argument validation; it does not indicate malformed YAML, only a missing input string.

Solutions

1. Ensure the YAML string is non-null before calling; use string.Empty if an empty document is intentional.
2. Fix the loader that returned null (missing resource, failed read) so it throws instead.
3. Guard with `if (yaml == null)` and raise an application-specific error naming the source.
4. Catch ArgumentNullException to convert it into a domain error.
5. Prefer loading via a stream overload with explicit file-not-found handling.

Example fix

// before
var yaml = LoadResource("config.yaml"); // returns null when missing
var cfg = (Config)serializer.Deserialize(yaml, typeof(Config));
// after
var yaml = LoadResource("config.yaml") ?? throw new FileNotFoundException("config.yaml not found");
var cfg = (Config)serializer.Deserialize(yaml, typeof(Config));

if (string.IsNullOrWhiteSpace(yaml)) throw new ArgumentException("YAML text is null or empty", nameof(yaml));

static bool HasYamlText(string s) => !string.IsNullOrEmpty(s);

try { return serializer.Deserialize(yaml, typeof(Config)); }
catch (ArgumentNullException) { throw new InvalidDataException("YAML text was not loaded"); }

When it happens

Trigger: Calling Deserialize(string fromText, Type expectedType, object existingObject) with fromText == null, e.g. File.ReadAllText returned via a path variable that was null, or a resource loader returning null.

Common situations: Embedded resource not found and loader returns null; config file read helper swallowing errors and returning null; unit tests passing uninitialized fixture strings.

Related errors

• reader
• Multiple identifiable objects with the same id
• Unable to decode asset part reference
• Unable to deserialize reference
• Unable to find class from tag

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/6b030210e3ac2cb2. Report an issue: GitHub.

Appendix: source

Thrown at sources/core/Stride.Core.Yaml/Serialization/Serializer.cs:353

        /// <param name="fromText">The text.</param>
        /// <param name="existingObject">The object to deserialize into. If null (the default) then a new object will be created</param>
        /// <returns>A deserialized object.</returns>
        public object Deserialize(string fromText, object existingObject = null)
        {
            return Deserialize(fromText, null, existingObject);
        }

        /// <summary>
        /// Deserializes an object from the specified string. with an expected specific type.
        /// </summary>
        /// <param name="fromText">From text.</param>
        /// <param name="expectedType">The expected type.</param>
        /// <param name="existingObject">The object to deserialize into. If null (the default) then a new object will be created</param>
        /// <returns>A deserialized object.</returns>
        /// <exception cref="System.ArgumentNullException">stream</exception>
        public object Deserialize(string fromText, Type expectedType, object existingObject = null)
        {
            if (fromText == null) throw new ArgumentNullException(nameof(fromText));
            return Deserialize(new StringReader(fromText), expectedType, existingObject);
        }

        /// <summary>
        /// Deserializes an object from the specified string. with an expected specific type.
        /// </summary>
        /// <param name="fromText">From text.</param>
        /// <param name="expectedType">The expected type.</param>
        /// <param name="existingObject">The object to deserialize into. If null (the default) then a new object will be created</param>
        /// <param name="context">The context used to deserialize this object.</param>
        /// <returns>A deserialized object.</returns>
        /// <exception cref="System.ArgumentNullException">stream</exception>
        public object Deserialize(string fromText, Type expectedType, object existingObject, out SerializerContext context)
        {
            if (fromText == null) throw new ArgumentNullException(nameof(fromText));
            return Deserialize(new StringReader(fromText), expectedType, existingObject, null, out context);
        }

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