Draft: Resolve "[Document Sealing] Implement PDF parser"

Closes #1

__tests__/index.test.ts

@@ -11,8 +11,8 @@ describe("PDF parser", () => {
     );
 
     const parser = new PDFparser(file);
-
     const actual = await parser.getPDFMeta();
+
     expect(actual.pages).toEqual(2);
   });
 
@@ -35,4 +35,16 @@ describe("PDF parser", () => {
       expect(error).toBeInstanceOf(AppError);
     }
   });
+
+  it("should throw error if file type is different then pdf", async () => {
+    const file = fs.readFileSync(path.resolve(__dirname, "./test.txt"));
+
+    try {
+      const parser = new PDFparser(file);
+      const actual = await parser.getPDFMeta();
+    } catch (error) {
+      expect(error).toBeInstanceOf(AppError);
+      expect(error.message).toEqual("Only pdf file type is supported");
+    }
+  });
 });