fix(javascript): bind Next page admission to source context

src/domain/javascript/javascriptRoutePaths.ts

@@ -1,3 +1,42 @@
+import { z } from "zod";
+import { digestSchema } from "../digests.js";
+
+const packageIdentitySchema = z.strictObject({
+  path: z.string().min(1),
+  sha256: digestSchema,
+  container_sha256: digestSchema,
+});
+export const nextAppSourceContextSchema = z.discriminatedUnion("kind", [
+  z.strictObject({
+    kind: z.literal("app-directory"),
+    directory: z.string().min(1),
+    package: packageIdentitySchema,
+  }),
+  z.strictObject({
+    kind: z.literal("compiled-directory"),
+    directory: z.string().min(1),
+    package: packageIdentitySchema,
+  }),
+  z.strictObject({
+    kind: z.literal("outside-app-directory"),
+    package: packageIdentitySchema,
+  }),
+  z.strictObject({
+    kind: z.literal("unknown"),
+    reason: z.string(),
+    package: packageIdentitySchema.nullable(),
+  }),
+]);
+export type NextAppSourceContext = z.infer<typeof nextAppSourceContextSchema>;
+export type NextAppRouteContext =
+  | { readonly kind: "source-path"; readonly source: NextAppSourceContext }
+  | { readonly kind: "script-url" }
+  | {
+      readonly kind: "source-literal";
+      readonly runtime: "next" | "unknown";
+    }
+  | { readonly kind: "source-reference" };
+
 /** URL route syntax, independent of filesystem path normalization. */
 export const routePath = (
   value: string,
@@ -19,27 +58,71 @@ export type NextAppRoutePath =
 /** Classify a page filename without treating missing routing context as absence. */
 export const classifyNextAppRoutePath = (
   raw: string,
+  context: NextAppRouteContext,
 ): NextAppRoutePath | undefined => {
-  if (raw.includes("\\")) return;
+  if (raw.includes("\\") || context.kind === "source-reference") return;
   let value = raw;
-  if (raw.includes("://")) {
+  if (
+    context.kind === "script-url" ||
+    (context.kind === "source-literal" && raw.includes("://"))
+  ) {
     try {
       value = new URL(raw).pathname;
     } catch {
       return;
     }
   }
-  // A deployment prefix may itself contain an `app` segment. Only the chunk
-  // path following Next's asset boundary can describe an App Router module.
-  const assetRoot = value.indexOf("/_next/");
-  if (assetRoot >= 0) value = value.slice(assetRoot + "/_next/".length);
-  const match =
-    /(?:^|\/)app\/(?:(.*?)\/)?page(?:-([^/?#]+)\.js|\.(?:[cm]?jsx?|tsx?)|)(?:[?#].*)?$/u.exec(
-      value,
+  // Ownership selects the routing root before page-segment conversion.
+  let relative: string | undefined;
+  let chunk = false;
+  if (context.kind === "source-path") {
+    if (context.source.kind === "outside-app-directory") return;
+    if (
+      context.source.kind === "app-directory" ||
+      context.source.kind === "compiled-directory"
+    ) {
+      const prefix = `${context.source.directory}/`;
+      if (!value.startsWith(prefix)) return;
+      relative = value.slice(prefix.length);
+      chunk = context.source.kind === "compiled-directory";
+    }
+  } else if (context.kind === "script-url" || context.runtime === "next") {
+    const boundary = "/_next/static/chunks/app/";
+    const assetRoot = value.indexOf(boundary);
+    const localChunk = ["static/chunks/app/", ".next/static/chunks/app/"].find(
+      (prefix) => value.startsWith(prefix),
     );
-  if (!match) return;
-  if (match[2] !== undefined && !/(?:^|\/)static\/chunks\/app\//u.test(value))
+    if (assetRoot >= 0) {
+      relative = value.slice(assetRoot + boundary.length);
+      chunk = true;
+    } else if (context.kind === "source-literal" && localChunk !== undefined) {
+      relative = value.slice(localChunk.length);
+      chunk = true;
+    } else if (context.kind === "source-literal") {
+      const prefix = value.startsWith("src/app/") ? "src/app/" : "app/";
+      if (value.startsWith(prefix)) relative = value.slice(prefix.length);
+    }
+  }
+  if (relative === undefined) {
+    if (
+      /(?:^|\/)app\/(?:.*\/)?page(?:\.[cm]?[jt]sx?|-[^/?#]+\.js|)(?:[?#].*)?$/u.test(
+        value,
+      )
+    )
+      return {
+        kind: "unknown",
+        reason:
+          context.kind === "source-path" && context.source.kind === "unknown"
+            ? context.source.reason
+            : "The page-shaped path has no established Next App Router root or runtime context.",
+      };
     return;
+  }
+  const match =
+    /^(?:(.*?)\/)?page(?:-([^/?#]+)\.js|\.(?:[cm]?jsx?|tsx?)|)(?:[?#].*)?$/u.exec(
+      relative,
+    );
+  if (match === null || (match[2] !== undefined && !chunk)) return;
   const sourceSegments = (match[1] ?? "").split("/");
   // A private folder excludes the whole page, including intercepted ancestors.
   // Keep filesystem segment spelling: only Next's explicit %5F escape is