Fix WebpackModuleRuntime fallback and add React Activity support#296
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- Fix WebpackModuleRuntime.getExports() crash when module not found in __webpack_module_cache__ (e.g. browser MCP injecting empty cache). Null-safe access gated behind `safeWebpackModuleExports` flag. - Convert ModuleRuntime from eager IIFE to lazy getModuleRuntime() so GlobalFlags are respected. `preferMetaModuleRuntime` flag controls whether Meta's __debug runtime is checked before webpack's cache. - Add REACT_ACTIVITY_TYPE (0xeae8) to IReactConsts, fix broken SymbolFor call, and register in visitor vtable to suppress "optimized visitors missing entry for Symbol(react.activity)" warnings. - Upgrade react-testapp to React 19 canary with real <Activity> component test and Vite __debug exclusion.
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Apr 20, 2026
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| const ModuleRuntime: ModuleRuntimeBase = (() => { | ||
| let _moduleRuntime: ModuleRuntimeBase | null = null; | ||
| function getModuleRuntime(): ModuleRuntimeBase { |
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do you expect this function to return different values on different invocations? For example, it may fail to get a _moduleRuntime for a while and then it starts working?
If the answer is no, then the previous pattern is better since it replaces the unnecessary check and is slightly faster.
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I don't expect it to change, I wanted to be able to check the global flag just for added safety - which isn't set if this is invoked immediately. When we remove the flags I can revert back. If you think this flag isn't totally necessary I could just swap the order to prefer meta modules, and keep the same pattern without a flag.
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Fix WebpackModuleRuntime.getExports() crash when module not found in webpack_module_cache (e.g. browser MCP injecting empty cache). Null-safe access gated behind
safeWebpackModuleExportsflag.Convert ModuleRuntime from eager IIFE to lazy getModuleRuntime() so GlobalFlags are respected.
preferMetaModuleRuntimeflag controls whether Meta's __debug runtime is checked before webpack's cache.Add REACT_ACTIVITY_TYPE (0xeae8) to IReactConsts, fix broken SymbolFor call, and register in visitor vtable to suppress "optimized visitors missing entry for Symbol(react.activity)" warnings.
Upgrade react-testapp to React 19 canary with real component test and Vite __debug exclusion.