feat: optional parse PDF metadata as JS dates (#44)

codewaseem · johannschopplich · web-flow · commit 0f9a0a3e1b88 · 2025-09-19T17:33:41.000+02:00
* feat: parse dates

* overwrite date properties if parseDate option is true

* perf: use Proxy object

---------

Co-authored-by: Johann Schopplich &lt;mail@johannschopplich.com&gt;
diff --git a/src/meta.ts b/src/meta.ts
@@ -1,14 +1,70 @@
 import type { DocumentInitParameters, PDFDocumentProxy } from 'pdfjs-dist/types/src/display/api'
-import { getDocumentProxy, isPDFDocumentProxy } from './utils'
+import { getDocumentProxy, getResolvedPDFJS, isPDFDocumentProxy } from './utils'
+
+const XMP_DATE_PROPERTIES = [
+  'xmp:createdate',
+  'xmp:modifydate',
+  'xmp:metadatadate',
+  'xap:createdate',
+  'xap:modifydate',
+  'xap:metadatadate',
+]
 
 export async function getMeta(
   data: DocumentInitParameters['data'] | PDFDocumentProxy,
+  options: {
+    parseDates?: boolean
+  } = {},
 ) {
   const pdf = isPDFDocumentProxy(data) ? data : await getDocumentProxy(data)
   const meta = await pdf.getMetadata()
 
+  const info = (meta?.info || {}) as Record<string, any>
+
+  if (options.parseDates) {
+    const { PDFDateString } = await getResolvedPDFJS()
+
+    // Primary date properties from /Info dictionary
+    if (info?.CreationDate) {
+      info.CreationDate = PDFDateString.toDateObject(info?.CreationDate)
+    }
+    if (info?.ModDate) {
+      info.ModDate = PDFDateString.toDateObject(info?.ModDate)
+    }
+
+    // Override metadata getter to parse XMP date properties
+    if (meta.metadata) {
+      meta.metadata = new Proxy(meta.metadata, {
+        get(target, prop) {
+          if (prop === 'get') {
+            return (name: string) => {
+              const value = target.get(name)
+
+              if (XMP_DATE_PROPERTIES.includes(name) && value) {
+                return parseISODateString(value)
+              }
+
+              return value
+            }
+          }
+          return target[prop as keyof typeof target]
+        },
+      })
+    }
+  }
+
   return {
-    info: (meta?.info ?? {}) as Record<string, any>,
-    metadata: ({ ...meta?.metadata }) as Record<string, any>,
+    info,
+    metadata: meta?.metadata || {},
+  }
+}
+
+function parseISODateString(isoDateString: string) {
+  if (!isoDateString)
+    return
+
+  const parsedDate = Date.parse(isoDateString)
+  if (!Number.isNaN(parsedDate)) {
+    return new Date(parsedDate)
   }
 }
diff --git a/test/index.test.ts b/test/index.test.ts
@@ -119,6 +119,37 @@ describe('unpdf', () => {
 
     expect(info.Creator).toMatchInlineSnapshot('"Writer"')
   })
+
+  it('parses PDF dates when parseDates option is enabled', async () => {
+    // Test basic date parsing from /Info dictionary
+    const { info: infoWithDates } = await getMeta(await getPDF(), { parseDates: true })
+
+    expect(infoWithDates.ModDate).toBeUndefined() // ModDate not present in sample.pdf
+    expect(infoWithDates.CreationDate).toBeInstanceOf(Date)
+    expect(infoWithDates.CreationDate.getFullYear()).toBe(2007)
+
+    // Test XMP metadata date parsing
+    const { info: infoLinks, metadata: linksMetadata } = await getMeta(
+      await getDocumentProxy(await getPDF('links.pdf')),
+      { parseDates: true },
+    )
+
+    // Verify /Info dates are parsed
+    expect(infoLinks.CreationDate).toBeInstanceOf(Date)
+    expect(infoLinks.ModDate).toBeInstanceOf(Date)
+    expect(infoLinks.CreationDate.getFullYear()).toBe(2024)
+    expect(infoLinks.ModDate.getFullYear()).toBe(2024)
+
+    // Verify XMP dates are parsed
+    expect(linksMetadata.get('xmp:createdate')).toBeInstanceOf(Date)
+    expect(linksMetadata.get('xmp:modifydate')).toBeInstanceOf(Date)
+    expect(linksMetadata.get('xmp:metadatadate')).toBeInstanceOf(Date)
+    expect(linksMetadata.get('xmp:createdate').getFullYear()).toBe(2024)
+
+    expect(linksMetadata.get('xap:createdate')).toBeNull()
+    expect(linksMetadata.get('xap:modifydate')).toBeNull()
+    expect(linksMetadata.get('xap:metadatadate')).toBeNull()
+  })
 })
 
 async function getPDF(filename = 'sample.pdf') {
