Prepack Versions Save

• Fix referentialization of optimized functions
• Fix serialization issues for nested optimized functions
• Model aliasing effects for array loop operators
• Fix dependency issues with cyclic prototype dependencies
• Fix problem where a bind call can use a variable before its definition
• Speed up visitor by skipping redundant generator scopes

• Bugfixes
• User-level stack overflows no longer crash prepack
• Website shows warnings when Prepack produces diagnostics

• Fixed bugs that could cause generated code to throw
• Improved evaluation of abstract conditionals
• Added CLI options --warnaserror, --diagnosticaserror, --nodiagnostic
• Added full support for React.Children.map mock

Highlights: Make simplification more robust when complexity limits are reached reduces loop iteration counter to 6 before bailing out We weren’t using the correct initializerAstNodeName in two places Tease apart expressions vs. statements for operation descriptors Simplify equality expressions where types are known Refactor AbstractObjectValue to use evaluateWithAbstractConditional Allow invalid render return values in the React reconciler update Babel 7 to stable release Speed up simplifier by using an implication cache per path branch Add basic support for throws in React

Fixes #2419 #2386 #2439 #2447 #2432 #2437 #2442

• Fix havoced binding not in optimized function
• Allow arrays with widened numeric properties to update index properties
• Fix nested for statement bailout with nested for-in
• Don’t record modified bindings for immutable bindings when havocing

Fixes #2151 #2222 #2279 #2393 #2399 #2404 #2411 #2414 #2415 Added a fuzz testing tool Added test cases Turn crash in JSON.stringify into a diagnostic Adds a arrayNestedOptimizedFunctionsEnabled flag to enable nested optimized functions derived from Array.prototype methods (like map) and Array.from Refactor assignment on partial or possibly deleted property Rewrote the joining logic to always do a full join at every join point Removed last remnants of delayUnsupportedRequires

- Many bug fixes
- Progress in support for nested optimized functions
- Fixing source map support
- Improved support for abstract behavior in switch statements
- Reduced memory usage of Prepack

• Bugfixes, refactors
• extended use of simplification to prepack more code
• improved shape modeling
• Added ability to materialize objects without havocing
• new --reproUnconditionally and --reproOnFatal options in Prepack
  • creates zip file with all files needed to debug the failure
  • creates repro.sh script that can open Nuclide debugger, pre-populating the original arguments causing the failure

• Enhanced dead code elimination for optimized functions
• Much of the buildNode and inline Babel logic has been moved to a dedicated ResidualOperationSerializer class
• Provide a way to temporarily disable effects tracking
• Simplified forked completion constructors
• React components can have their props modelled via __optimizeReactComponentTree

• Support modeling of shapes of optimized function arguments
• fix test262 to fail CircleCI test if not enough tests pass
• upgrades Prepack to use Babel 7.0.0-beta.53
• Nuclide compatibility fix