Feature to specify 'evaluateOnNewDocument' to run script before page …

…scripts (#269) Co-authored-by: Rasmus Sørensen <[email protected]>
Studiosity · Nov 26, 2024 · d8ea42e · d8ea42e
1 parent 8a359b1
commit d8ea42e
Show file tree

Hide file tree

Showing 3 changed files with 30 additions and 0 deletions.
diff --git a/README.md b/README.md
@@ -174,6 +174,12 @@ by passing it to the `execute_script` option.
 Grover.new(<some url>, execute_script: 'document.getElementsByTagName("footer")[0].innerText = "Hey"').to_pdf
 ```
 
+You can also evaluate JavaScript on the page before any of its scripts is run, by passing it a string to the `evaluate_on_new_document` option. See https://github.com/puppeteer/puppeteer/blob/main/docs/api/puppeteer.page.evaluateonnewdocument.md
+
+```javascript
+Grover.new(<some url>, evaluate_on_new_document: 'window.someConfig = "some value"').to_pdf
+```
+
 #### Basic authentication
 For requesting a page with basic authentication, `username` and `password` options can be provided. Note that this
 only really makes sense if you're calling Grover directly (and not via middleware).

diff --git a/lib/grover/js/processor.cjs b/lib/grover/js/processor.cjs
@@ -184,6 +184,12 @@ const _processPage = (async (convertAction, uriOrHtml, options) => {
       await page.setGeolocation(geolocation);
     }
 
+    // If specified, add script to evaluate before the page loads
+    const evaluateOnNewDocument = options.evaluateOnNewDocument; delete options.evaluateOnNewDocument;
+    if (evaluateOnNewDocument !== undefined) {
+      await page.evaluateOnNewDocument(evaluateOnNewDocument);
+    }
+
     const raiseOnRequestFailure = options.raiseOnRequestFailure; delete options.raiseOnRequestFailure;
     if (raiseOnRequestFailure) {
       page.on('requestfinished', (request) => {

diff --git a/spec/grover/processor_spec.rb b/spec/grover/processor_spec.rb
@@ -584,6 +584,24 @@
         end
       end
 
+      context 'when evaluateOnNewDocument option is specified' do
+        let(:url_or_html) do
+          <<-HTML
+            <html>
+              <body>
+                Evaluate on new doc <span id="test">did not run</span>
+                <script type="text/javascript">
+                  document.getElementById("test").innerHTML = window.preEvalContent;
+                </script>
+              </body>
+            </html>
+          HTML
+        end
+        let(:options) { { 'evaluateOnNewDocument' => 'window.preEvalContent = "ran!"' } }
+
+        it { expect(pdf_text_content).to eq 'Evaluate on new doc ran!' }
+      end
+
       context 'when evaluate option is specified' do
         let(:url_or_html) { '<html><body></body></html>' }
         let(:options) { basic_header_footer_options.merge('executeScript' => script) }