At present, pretty much every method on Debugger.Script is implemented with a mozilla::Variant matcher class on the referent type, branching to handle JavaScript and Web Assembly scripts appropriately. It would be much nicer to split this into Debugger.Script and Debugger.WebAssemblyScript, and let each of them have the methods that they need.

Most methods and accessors on Debugger.Script.prototype throw TypeError when called on a Web Assembly script. Those that actually do something interesting are:

• getPossibleBreakpoints
• getPossibleBreakpointOffsets
• getOffsetMetadata
• setBreakpoint
• clearBreakpoint
• clearAllBreakpoints

The following accessors and methods don't throw an error, but don't return an
especially informative value either:

• startLine (always returns 1)
• lineCount (always returns 0)
• source (returns a synthesized Debugger.Source object)
• format (returns "wasm")