The parser was chomping on commas present after the arrow function expression. eg. [x=>x,2] would parse as [x=>(x,2)] instead of [(x=>x),2].
This is not the case anymore. I've added a small test to prove this.
Adds the ability for a scope (either a function or the entire program)
to be in strict mode. Scopes default to non-strict mode.
There are two ways to determine the strict-ness of the JS engine:
1. In the parser, this can be accessed with the parser_state variable
m_is_strict_mode boolean. If true, the Parser is currently parsing in
strict mode. This is done so that the Parser can generate syntax
errors at parse time, which is required in some cases.
2. With Interpreter.is_strict_mode(). This allows strict mode checking
at runtime as opposed to compile time.
Additionally, in order to test this, a global isStrictMode() function
has been added to the JS ReplObject under the test-mode flag.
A regression was introduced in dc9b4da where the parser would
incorrectly parse the assignment of arrow functions to (non-declaration)
variables. For example, consider:
a = () => {}
Because the parser was aware of default parameters, in
try_parse_arrow_function, the equals sign would be interpreted as a
default argument, leading to incorrect parsing of the overall
expression. Also resulted in some funny behavior
(a = () => {} => {} worked just fine!).
The simple fix is to only look for default parameters if the arrow
function is required to have parenthesis.
The addition of assert functions to Userland/js
was done before we had load(..) implemented. Now
that it exists, it seems like the right move the
test helper functions to pure javascript instead
of poluting js with random global functions.
