feat: add preferStatic to ISC (#1648)

src/runtimes/node/in_source_config/index.ts

@@ -131,7 +131,12 @@ export const parseSource = (
       result.methods = normalizeMethods(configExport.method, functionName)
     }
 
-    result.routes = getRoutes(configExport.path, functionName, result.methods ?? [])
+    result.routes = getRoutes({
+      functionName,
+      methods: result.methods ?? [],
+      path: configExport.path,
+      preferStatic: configExport.preferStatic === true,
+    })
 
     return result
   }

src/utils/routes.ts

@@ -4,7 +4,10 @@ import { FunctionBundlingUserError } from './error.js'
 import { nonNullable } from './non_nullable.js'
 import { ExtendedURLPattern } from './urlpattern.js'
 
-export type Route = { pattern: string; methods: string[] } & ({ literal: string } | { expression: string })
+export type Route = { pattern: string; methods: string[]; prefer_static?: boolean } & (
+  | { literal: string }
+  | { expression: string }
+)
 
 // Based on https://developer.mozilla.org/en-US/docs/Web/API/URL_Pattern_API.
 const isExpression = (part: string) =>
@@ -18,11 +21,18 @@ const isPathLiteral = (path: string) => {
   return parts.every((part) => !isExpression(part))
 }
 
+interface GetRouteOption {
+  functionName: string
+  methods: string[]
+  path: unknown
+  preferStatic: boolean
+}
+
 /**
  * Takes an element from a `path` declaration and returns a Route element that
  * represents it.
  */
-const getRoute = (path: unknown, functionName: string, methods: string[]): Route | undefined => {
+const getRoute = ({ functionName, methods, path, preferStatic }: GetRouteOption): Route | undefined => {
   if (typeof path !== 'string') {
     throw new FunctionBundlingUserError(`'path' property must be a string, found '${JSON.stringify(path)}'`, {
       functionName,
@@ -38,7 +48,7 @@ const getRoute = (path: unknown, functionName: string, methods: string[]): Route
   }
 
   if (isPathLiteral(path)) {
-    return { pattern: path, literal: path, methods }
+    return { pattern: path, literal: path, methods, prefer_static: preferStatic || undefined }
   }
 
   try {
@@ -53,7 +63,7 @@ const getRoute = (path: unknown, functionName: string, methods: string[]): Route
     // for both `/foo` and `/foo/`.
     const normalizedRegex = `^${regex}\\/?$`
 
-    return { pattern: path, expression: normalizedRegex, methods }
+    return { pattern: path, expression: normalizedRegex, methods, prefer_static: preferStatic || undefined }
   } catch {
     throw new FunctionBundlingUserError(`'${path}' is not a valid path according to the URLPattern specification`, {
       functionName,
@@ -62,17 +72,38 @@ const getRoute = (path: unknown, functionName: string, methods: string[]): Route
   }
 }
 
+interface GetRoutesOptions {
+  functionName: string
+  methods: string[]
+  path: unknown
+  preferStatic?: boolean
+}
+
 /**
  * Takes a `path` declaration, normalizes it into an array, and processes the
  * individual elements to obtain an array of `Route` expressions.
  */
-export const getRoutes = (input: unknown, functionName: string, methods: string[]): Route[] => {
-  if (!input) {
+export const getRoutes = ({
+  functionName,
+  methods,
+  path: pathOrPaths,
+  preferStatic = false,
+}: GetRoutesOptions): Route[] => {
+  if (!pathOrPaths) {
     return []
   }
 
-  const paths = [...new Set(Array.isArray(input) ? input : [input])]
-  const routes = paths.map((path) => getRoute(path, functionName, methods ?? [])).filter(nonNullable)
+  const paths = [...new Set(Array.isArray(pathOrPaths) ? pathOrPaths : [pathOrPaths])]
+  const routes = paths
+    .map((path) =>
+      getRoute({
+        functionName,
+        methods,
+        path,
+        preferStatic,
+      }),
+    )
+    .filter(nonNullable)
 
   return routes
 }

tests/unit/runtimes/node/in_source_config.test.ts

@@ -593,4 +593,68 @@ describe('V2 API', () => {
       expect(routes).toEqual([{ pattern: '/products', literal: '/products', methods: [] }])
     })
   })
+
+  describe('`preferStatic` property', () => {
+    test('Sets a `prefer_static` property on a single route', () => {
+      const source = `export default async () => {
+        return new Response("Hello!")
+      }
+  
+      export const config = {
+        path: "/products",
+        preferStatic: true
+      }`
+
+      const { routes } = parseSource(source, options)
+
+      expect(routes).toEqual([{ pattern: '/products', literal: '/products', methods: [], prefer_static: true }])
+    })
+
+    test('Sets a `prefer_static` property on all routes', () => {
+      const source = `export default async () => {
+        return new Response("Hello!")
+      }
+  
+      export const config = {
+        path: ["/items", "/products"],
+        preferStatic: true
+      }`
+
+      const { routes } = parseSource(source, options)
+
+      expect(routes).toEqual([
+        { pattern: '/items', literal: '/items', methods: [], prefer_static: true },
+        { pattern: '/products', literal: '/products', methods: [], prefer_static: true },
+      ])
+    })
+
+    test('Does not set a `prefer_static` property if `preferStatic` is not a boolean', () => {
+      const source = `export default async () => {
+        return new Response("Hello!")
+      }
+  
+      export const config = {
+        path: "/products",
+        preferStatic: "yep"
+      }`
+
+      const { routes } = parseSource(source, options)
+
+      expect(routes).toEqual([{ pattern: '/products', literal: '/products', methods: [] }])
+    })
+
+    test('Does not set a `prefer_static` property if `preferStatic` is not set', () => {
+      const source = `export default async () => {
+        return new Response("Hello!")
+      }
+  
+      export const config = {
+        path: "/products"
+      }`
+
+      const { routes } = parseSource(source, options)
+
+      expect(routes).toEqual([{ pattern: '/products', literal: '/products', methods: [] }])
+    })
+  })
 })