When a PutById / PutByValue bytecode operation results in accessing a
nullish object, we now include the name of the property and the object
being accessed in the exception message (if available). This should make
it easier to debug live websites.
For example, the following errors would all previously produce a generic
error message of "ToObject on null or undefined":
> foo = null
> foo.bar = 1
Uncaught exception:
[TypeError] Cannot access property "bar" on null object "foo"
at <unknown>
> foo = { bar: undefined }
> foo.bar.baz = 1
Uncaught exception:
[TypeError] Cannot access property "baz" on undefined object "foo.bar"
at <unknown>
Note we certainly don't capture all possible nullish property write
accesses here. This just covers cases I've seen most on live websites;
we can cover more cases as they arise.
When a GetById / GetByValue bytecode operation results in accessing a
nullish object, we now include the name of the property and the object
being accessed in the exception message (if available). This should make
it easier to debug live websites.
For example, the following errors would all previously produce a generic
error message of "ToObject on null or undefined":
> foo = null
> foo.bar
Uncaught exception:
[TypeError] Cannot access property "bar" on null object "foo"
at <unknown>
> foo = { bar: undefined }
> foo.bar.baz
Uncaught exception:
[TypeError] Cannot access property "baz" on undefined object "foo.bar"
at <unknown>
Note we certainly don't capture all possible nullish property read
accesses here. This just covers cases I've seen most on live websites;
we can cover more cases as they arise.