WebAssembly.runtimeError

The RuntimeError() constructor of the WebAssembly global object creates a new WebAssembly RuntimeError instance — the type that is thrown whenever WebAssembly specifies a trap.

Syntax

new WebAssembly.RuntimeError(message, fileName, lineNumber)

Parameters

message Optional

Human-readable description of the error.

fileName Optional

The name of the file containing the code that caused the exception.

lineNumber Optional

The line number of the code that caused the exception.

Properties

The RuntimeError constructor contains no unique properties of its own, however, it does inherit some methods through the prototype chain.

WebAssembly.RuntimeError.prototype.constructor

Specifies the function that created an instance's prototype.

WebAssembly.RuntimeError.prototype.message

Error message. Although ECMA-262 specifies that URIError should provide its own message property, in SpiderMonkey, it inherits Error.prototype.message.

WebAssembly.RuntimeError.prototype.name

Error name. Inherited from Error.

WebAssembly.RuntimeError.prototype.fileName

Path to file that raised this error. Inherited from Error.

WebAssembly.RuntimeError.prototype.lineNumber

Line number in file that raised this error. Inherited from Error.

WebAssembly.RuntimeError.prototype.columnNumber

Column number in line that raised this error. Inherited from Error.

WebAssembly.RuntimeError.prototype.stack

Stack trace. Inherited from Error.

Methods

The RuntimeError constructor contains no methods of its own, however, it does inherit some methods through the prototype chain.

WebAssembly.RuntimeError.prototype.toSource()

Returns code that could eval to the same error. Inherited from Error.

WebAssembly.RuntimeError.prototype.toString()

Returns a string representing the specified Error object.. Inherited from Error.

Examples

The following snippet creates a new RuntimeError instance, and logs its details to the console:

try {
  throw new WebAssembly.RuntimeError('Hello', 'someFile', 10);
} catch (e) {
  console.log(e instanceof RuntimeError); // true
  console.log(e.message);                 // "Hello"
  console.log(e.name);                    // "RuntimeError"
  console.log(e.fileName);                // "someFile"
  console.log(e.lineNumber);              // 10
  console.log(e.columnNumber);            // 0
  console.log(e.stack);                   // returns the location where the code was run
}

Specifications

Specification	Status	Comment
Unknown The definition of 'WebAssembly constructors' in that specification.	Unknown	Initial WebAssembly draft definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'NativeError' in that specification.	Draft	Definition of standard NativeError types.

Browser compatibility

[1] Experimental support can be enabled in Chrome 51+ and Opera 38+ by going to chrome://flags and enabling the Experimental WebAssembly flag.

[2] Experimental support can be enabled in Firefox 47+ by enabling the javascript.options.wasm flag in about:config.

See also

• WebAssembly landing page.
• WebAssembly concepts
• Using the WebAssembly JavaScript API