test: check actual output generated from printToPDF (#21949)

spec-main/api-web-contents-spec.ts

@@ -9,6 +9,7 @@ import { emittedOnce } from './events-helpers'
 import { closeAllWindows } from './window-helpers'
 import { ifdescribe, ifit } from './spec-helpers'
 
+const pdfjs = require('pdfjs-dist')
 const fixturesPath = path.resolve(__dirname, '..', 'spec', 'fixtures')
 const features = process.electronBinding('features')
 
@@ -1447,6 +1448,29 @@ describe('webContents module', () => {
       expect(data).to.be.an.instanceof(Buffer).that.is.not.empty()
     })
 
+    it('respects custom settings', async () => {
+      w.loadFile(path.join(__dirname, 'fixtures', 'api', 'print-to-pdf.html'))
+      await emittedOnce(w.webContents, 'did-finish-load')
+
+      const data = await w.webContents.printToPDF({
+        pageRanges: {
+          from: 0,
+          to: 2
+        },
+        landscape: true
+      })
+
+      const doc = await pdfjs.getDocument(data).promise
+
+      // Check that correct # of pages are rendered.
+      expect(doc.numPages).to.equal(3)
+
+      // Check that PDF is generated in landscape mode.
+      const firstPage = await doc.getPage(1)
+      const { width, height } = firstPage.getViewport({ scale: 100 })
+      expect(width).to.be.greaterThan(height)
+    })
+
     it('does not crash when called multiple times', async () => {
       const promises = []
       for (let i = 0; i < 2; i++) {