refactor: use pdf page buffer for snapshots

package.json

@@ -143,6 +143,6 @@
     "svg"
   ],
   "volta": {
-    "node": "20.8.0"
+    "node": "20.8.1"
   }
 }

src/pdf/swissqrbill.test.ts

@@ -14,9 +14,10 @@ describe("qr-bill", async () => {
     const qrBill = new SwissQRBill(minimalRequired);
 
     qrBill.attachTo(pdf);
-    pdf.end();
 
-    await expect(pdf.snapshot).resolves.toMatchSnapshot();
+    await pdf.writeFile();
+
+    expect(pdf.snapshots).toMatchSnapshot();
   });
 
   it("should render the qr bill in a a4 document with insufficient space on a new page", async () => {
@@ -30,9 +31,10 @@ describe("qr-bill", async () => {
     });
 
     qrBill.attachTo(pdf);
-    pdf.end();
 
-    await expect(pdf.snapshot).resolves.toMatchSnapshot();
+    await pdf.writeFile();
+
+    expect(pdf.snapshots).toMatchSnapshot();
   });
 
   it("should render the qr bill in a a4 document with multiple pages and enough space on the last page", async () => {
@@ -41,9 +43,10 @@ describe("qr-bill", async () => {
 
     pdf.addPage();
     qrBill.attachTo(pdf);
-    pdf.end();
 
-    await expect(pdf.snapshot).resolves.toMatchSnapshot();
+    await pdf.writeFile();
+
+    expect(pdf.snapshots).toMatchSnapshot();
   });
 
   it("should render the qr bill in a a4 document with multiple pages and insufficient space on a new page", async () => {
@@ -58,9 +61,9 @@ describe("qr-bill", async () => {
     });
 
     qrBill.attachTo(pdf);
-    pdf.end();
+    await pdf.writeFile();
 
-    await expect(pdf.snapshot).resolves.toMatchSnapshot();
+    expect(pdf.snapshots).toMatchSnapshot();
   });
 
   it("should render multiple qr bills on the same page if enough space is left and the positions are fixed", async () => {
@@ -72,19 +75,21 @@ describe("qr-bill", async () => {
     qrBill1.attachTo(pdf, 0, 0);
     qrBill2.attachTo(pdf, 0, mm2pt(105));
     qrBill3.attachTo(pdf, 0, mm2pt(210));
-    pdf.end();
 
-    await expect(pdf.snapshot).resolves.toMatchSnapshot();
+    await pdf.writeFile();
+
+    expect(pdf.snapshots).toMatchSnapshot();
   });
 
   it("should render the qr bills freely on a page", async () => {
     const pdf = new TestDocument("qr-bill/freely-placed.pdf", { layout: "landscape", size: "A4" });
     const qrBill = new SwissQRBill(minimalRequired);
 
     qrBill.attachTo(pdf, mm2pt(43.5), mm2pt(52.5));
-    pdf.end();
 
-    await expect(pdf.snapshot).resolves.toMatchSnapshot();
+    await pdf.writeFile();
+
+    expect(pdf.snapshots).toMatchSnapshot();
   });
 
 });