ENG-2908: Serve IAB TCF CMP stub as fides-stub.js from Privacy Center (#7642)

Author: gilluminate

changelog/7642-serve-iab-tcf-stub.yaml

@@ -0,0 +1,4 @@
+type: Added
+description: Added IAB TCF CMP stub served as /fides-stub.js from Privacy Center
+pr: 7642
+labels: []

clients/fides-js/package.json

@@ -63,6 +63,7 @@
     "uuid": "^9.0.0"
   },
   "devDependencies": {
+    "@iabtechlabtcf/stub": "1.5.21",
     "@rollup/plugin-alias": "^5.0.0",
     "@rollup/plugin-commonjs": "^25.0.7",
     "@rollup/plugin-json": "^6.0.0",

clients/fides-js/rollup.config.mjs

@@ -256,6 +256,48 @@ const previewScript = {
 // Add preview script to build after the main scripts
 rollupOptions.push(previewScript);
 
+/**
+ * Copy the official IAB TCF CMP stub to privacy-center as a static file.
+ * Publishers load this before fides.js so that window.__tcfapi is available
+ * immediately for downstream ad scripts.
+ *
+ * Uses a virtual module as input since there is no source to compile — we
+ * only need rollup to run the copy plugin.
+ */
+const copyStub = {
+  input: "\0virtual-stub",
+  plugins: [
+    {
+      name: "virtual-stub",
+      resolveId(id) {
+        if (id === "\0virtual-stub") return id;
+      },
+      load(id) {
+        if (id === "\0virtual-stub") return "// IAB TCF stub copy-only entry";
+      },
+    },
+    copy({
+      targets: [
+        {
+          src: "../node_modules/@iabtechlabtcf/stub/lib/stub.js",
+          dest: "../privacy-center/public/lib/",
+          rename: "fides-stub.js",
+        },
+      ],
+      verbose: true,
+      hook: "buildStart",
+    }),
+  ],
+  output: [
+    {
+      file: "dist/fides-stub.js",
+      format: "es",
+    },
+  ],
+};
+
+rollupOptions.push(copyStub);
+
 /**
  * In addition to our regular built outputs (like fides.js!) also generate a
  * fides-types.d.ts file from  our documented types for external use.