next.js

c3e6680b - perf(build): optimize buildAppStaticPaths performance and add helper function (#81386)

perf(build): optimize buildAppStaticPaths performance and add helper function (#81386) ### What? Optimizes the `buildAppStaticPaths` function performance and extracts a helper function `calculateFallbackMode` to reduce code duplication. ### Why? The `buildAppStaticPaths` function had several performance bottlenecks: 1. **Repeated regex pattern compilation**: Route parameter patterns were being compiled inside the loop for every route, causing unnecessary overhead 2. **Inefficient root parameter lookups**: Using `Array.includes()` for root parameter checks resulted in O(n) lookups for each parameter 3. **Duplicated fallback mode logic**: The same fallback mode calculation was repeated in multiple places, making the code harder to maintain and prone to inconsistencies These inefficiencies became more apparent when processing large numbers of routes with complex parameter structures. ### How? **Performance optimizations:** - Pre-compile regex patterns for route parameters outside the loop and store them in a Map for O(1) lookups - Convert `rootParamKeys` to a Set for O(1) lookup time instead of O(n) array searches - Optimize the fallback parameter collection loop to break early and avoid redundant iterations **Code organization:** - Extract `calculateFallbackMode` helper function to eliminate code duplication - Add comprehensive tests for the new helper function to ensure correctness - Simplify the main loop logic by using the pre-compiled patterns and optimized data structures