Proposal README
Proposal rendered spec

For testing the tests, the proposal is shipped in v8.

• Tests for new function JSON.isRawJSON:
  • Boilerplate:
    • Function length.
    • Function name.
    • Property descriptor.
    • Function is not a constructor.
  • Can be invoked as a function with success cases:
    • An instance created by a call to JSON.rawJSON.
    • Some objects without an [[IsRawJSON]] internal slot: {}, [].
    • Some non-Objects: null, undefinded, a Boolean, a symbol, a number.
• Tests for new function JSON.rawJSON:
  • Boilerplate:
    • Function length.
    • Function name.
    • Function is not a constructor.
    • Property descriptor.
  • Can be invoked as a function
    • Success cases
      • Number, negative number, string, true, false, null
      • Returned object has the correct shape (null prototype, rawJSON own property)
      • Returned object is frozen
        json-parse-with-source: Sync with stage 4 PR and complete testing plan #4682
    • Failure cases, throwing:
      • SyntaxError in case of:
        • The empty string.
        • A string starting or ending with a tab, a linefeed, a carriage return, or a space.
        • A non-Array object literal: {}.
        • An Array literal: [1].
      • TypeError when trying to extend a rawJSON result object.
        json-parse-with-source: Sync with stage 4 PR and complete testing plan #4682
• Tests for the new abstract operations in the algorithm of JSON.parse, each test should have a callable reviver argument:
  • For paths in CreateJSONParseRecord, only success cases (normal output), a test for each branch:
    • an Array literal
    • an Object literal
    • an Object literal with a repeated key
    • NullLiteral, BooleanLiteral, NumericLiteral, StringLiteral, ArrayLiteral, ObjectLiteral, UnaryExpression
    • a combination of all the above success cases nested
  • For paths in InternalizeJSONProperty, and the interaction with JSON.stringify, test with a reviver that modifies the holder object, as mentioned in tc39 issue 39:
    json-parse-with-source: Sync with stage 4 PR and complete testing plan #4682
    • [array and plain object] overwrite of not-yet-processed entry should result in absence of source for that entry
      • primitive to non-primitive
      • non-primitive to primitive
      • non-primitive to a clone (same data but different identity)
      • primitive to a different primitive
    • [array and plain object] overwrite and restoration of not-yet-processed entry should preserve source for that entry
      • primitive
      • non-primitive
    • [array] splicing out an item should result in absence of source from the affected index forward
      • ...but restoring items at their original index should preserve source
• Test the overall intended functionality with examples from the proposal README and slides (linked in README).
  • Test that reviver function is applied to the source, not the parsed value, by roundtripping:
    • JSON.parse(" 9999999999999999", (key, val) => BigInt(val)) // → 9999999999999999n
    • other?