fix(lambda-at-edge): fail build when "public/static" folder exists as this conflicts with static/* cache behavior (#709)

Author: dphang

packages/libs/lambda-at-edge/src/build.ts

@@ -623,6 +623,13 @@ class Builder {
         return copyIfExists(source, destination);
       });
 
+    // Check if public/static exists and fail build since this conflicts with static/* behavior.
+    if (await fse.pathExists(path.join(nextStaticDir, "public", "static"))) {
+      throw new Error(
+        "You cannot have assets in the directory [public/static] as they conflict with the static/* CloudFront cache behavior. Please move these assets into another directory."
+      );
+    }
+
     const buildPublicOrStaticDirectory = async (
       directory: "public" | "static"
     ) => {

packages/libs/lambda-at-edge/tests/build/build.test.ts

@@ -341,6 +341,31 @@ describe("Builder Tests", () => {
     });
   });
 
+  describe("Build edge cases", () => {
+    let builder: Builder;
+
+    beforeEach(async () => {
+      const mockExeca = execa as jest.Mock;
+      mockExeca.mockResolvedValueOnce();
+
+      fseRemoveSpy = jest.spyOn(fse, "remove").mockImplementation(() => {
+        return;
+      });
+      fseEmptyDirSpy = jest.spyOn(fse, "emptyDir");
+    });
+
+    it("fails build when there is a public/static directory that conflicts with static/* behavior", async () => {
+      const fixturePath = join(
+        __dirname,
+        "./simple-app-fixture-public-static-error"
+      );
+      builder = new Builder(fixturePath, outputDir, {});
+      await expect(builder.build()).rejects.toThrow(
+        "You cannot have assets in the directory [public/static] as they conflict with the static/* CloudFront cache behavior. Please move these assets into another directory."
+      );
+    });
+  });
+
   describe("Custom handler", () => {
     let fseRemoveSpy: jest.SpyInstance;
     let fseEmptyDirSpy: jest.SpyInstance;

packages/libs/lambda-at-edge/tests/build/simple-app-fixture-public-static-error/.next/BUILD_ID

@@ -0,0 +1 @@
+test-build-id

packages/libs/lambda-at-edge/tests/build/simple-app-fixture-public-static-error/.next/cache/placeholder.txt

@@ -0,0 +1 @@
+Having a cache/ folder allows to test the cleanup of .next/ except for cache/ for faster builds

packages/libs/lambda-at-edge/tests/build/simple-app-fixture-public-static-error/.next/prerender-manifest.json

@@ -0,0 +1,15 @@
+{
+  "version": 2,
+  "routes": {
+    "/": {
+      "initialRevalidateSeconds": false,
+      "srcRoute": null,
+      "dataRoute": "/_next/data/zsWqBqLjpgRmswfQomanp/index.json"
+    },
+    "/contact": {
+      "initialRevalidateSeconds": false,
+      "srcRoute": null,
+      "dataRoute": "/_next/data/zsWqBqLjpgRmswfQomanp/contact.json"
+    }
+  }
+}

packages/libs/lambda-at-edge/tests/build/simple-app-fixture-public-static-error/.next/routes-manifest.json

@@ -0,0 +1 @@
+{"version":1,"pages404":true,"basePath":"","redirects":[],"rewrites":[],"headers":[],"dynamicRoutes":[]}

packages/libs/lambda-at-edge/tests/build/simple-app-fixture-public-static-error/.next/serverless/pages-manifest.json

@@ -0,0 +1,3 @@
+{
+  "/": "pages/index.js"
+}

packages/libs/lambda-at-edge/tests/build/simple-app-fixture-public-static-error/.next/serverless/pages/index.html

@@ -0,0 +1 @@
+module.exports = { target: "serverless" };