fix: add pdfjs at compatibility polyfill

Agent-Logs-Url: https://github.com/kekingcn/kkFileView/sessions/287f0212-d368-4b59-ae70-0374fb3fe76f

Co-authored-by: klboke <18591662+klboke@users.noreply.github.com>

server/src/test/java/cn/keking/PdfViewerCompatibilityTests.java

@@ -0,0 +1,32 @@
+package cn.keking;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
+public class PdfViewerCompatibilityTests {
+
+    @Test
+    void shouldLoadCompatibilityModuleBeforePdfJs() throws IOException {
+        String viewerHtml = readResource("/static/pdfjs/web/viewer.html");
+
+        assert viewerHtml.contains("<script src=\"compatibility.mjs\" type=\"module\"></script>");
+        assert viewerHtml.indexOf("compatibility.mjs") < viewerHtml.indexOf("../build/pdf.mjs");
+    }
+
+    @Test
+    void shouldLoadCompatibilityModuleInPdfWorker() throws IOException {
+        String workerScript = readResource("/static/pdfjs/build/pdf.worker.mjs");
+
+        assert workerScript.contains("import \"../web/compatibility.mjs\";");
+    }
+
+    private String readResource(String resourcePath) throws IOException {
+        try (InputStream inputStream = getClass().getResourceAsStream(resourcePath)) {
+            assert inputStream != null;
+            return new String(inputStream.readAllBytes(), StandardCharsets.UTF_8);
+        }
+    }
+}