1 files changed, 49 insertions, 0 deletions
diff --git a/remote/test/puppeteer/packages/puppeteer-core/src/common/ScriptInjector.ts b/remote/test/puppeteer/packages/puppeteer-core/src/common/ScriptInjector.ts
new file mode 100644
index 0000000000..cb0c039530
--- /dev/null
+++ b/remote/test/puppeteer/packages/puppeteer-core/src/common/ScriptInjector.ts
@@ -0,0 +1,49 @@
+import {source as injectedSource} from '../generated/injected.js';
+
+class ScriptInjector {
+  #updated = false;
+  #amendments = new Set<string>();
+
+  // Appends a statement of the form `(PuppeteerUtil) => {...}`.
+  append(statement: string): void {
+    this.#update(() => {
+      this.#amendments.add(statement);
+    });
+  }
+
+  pop(statement: string): void {
+    this.#update(() => {
+      this.#amendments.delete(statement);
+    });
+  }
+
+  inject(inject: (script: string) => void, force = false) {
+    if (this.#updated || force) {
+      inject(this.#get());
+    }
+    this.#updated = false;
+  }
+
+  #update(callback: () => void): void {
+    callback();
+    this.#updated = true;
+  }
+
+  #get(): string {
+    return `(() => {
+      const module = {};
+      ${injectedSource}
+      ${[...this.#amendments]
+        .map(statement => {
+          return `(${statement})(module.exports.default);`;
+        })
+        .join('')}
+      return module.exports.default;
+    })()`;
+  }
+}
+
+/**
+ * @internal
+ */
+export const scriptInjector = new ScriptInjector();