Now with

• SES lockdown Hermes compat tracking issue #1891

done, here are the non-blocking improvements to improve: SES <--> Hermes <--> React Native compatibility

• whitelistIntrinsics(intrinsics, markVirtualizedNativeFunction);
  • feat(ses): improve Hermes check on function caller and arguments #2722
• a SES-specific lint rule, like the we have for @endo/polymorphic*, so that we get a lint error if we use this inside an arrow function, since evidently that will break the Hermes version.
• add a lint rule that warn on async generator usages that Hermes requires special handling (getAsyncGeneratorFunctionInstance) and silence the lint warning in the EvalError fallback case (which has the special handling)
• fix new Compartment() fails on removeUnpermittedIntrinsics at Tolerating undeletable intrinsics.%CompartmentPrototype%.importNow.prototype === undefined: Uncaught TypeError: property is not configurable
  • add Compartment to Hermes smoke test (snippet)
• add v0.13.0 for RN0.75.x to endo CI (no npm, github only)

  • The previous main distribution mechanism - hermes-engine.npm and hermes-engine-cli.npm - has been deprecated. At least for now, we don't have plans to restart it, since it appears that all use cases are served by RN. It also appears that - shockingly (at least to me) - NPM is really really bad at efficiently distributing binaries for different platforms, which is why RN chose a different mechanism for distributing our binaries - Maven. Short-hand methods don't have prototype / construct facebook/hermes#1371 (comment)

• add Hermes "for RN0.76.x" to endo CI (metamask-mobile RN upgrade version)
  • since neither npm nor github distributions exist here, our next best option is to rely on hermes tags .tar.gz's
  • OR npm i react-native@0.76.6 then use node_modules/react-native/sdks/hermesc/osx-bin
  • for custom release branches we must more laboriously build and run hermes
• add Static Hermes to endo CI - build and run it with cmake git ninja
• expand Hermes smoke test suite - 1 evalTaming unsafe-eval (done) 2 evalTaming no-eval
• replace immutableArrayBufferPonyfier Hermes transform with [conditional sync import](feat(immutable-arraybuffer): sliceToImmutable Hermes ponyfill and shim #2785 (comment))
  • fix(immutable-arraybuffer): unify shim to work on more platforms #2855

Other

• // hardenIntrinsics(); // React Native runtime only, app fails to boot (consider e2e test in CI)
  • feat: SES lockdown v1.0.0 (Android Hermes) MetaMask/metamask-mobile#8161 lines
  • feat: @lavamoat/react-native-lockdown LavaMoat/LavaMoat#1438
• hardenIntrinsics() twice emits ses_already_locked_down #2760
• Detect if ses is being transformed #662