feat(permanentid): generate permanent id when missing (#7)

https://coveord.atlassian.net/browse/CDX-302

src/documentBuilder.ts

@@ -1,4 +1,5 @@
 import dayjs = require('dayjs');
+import {createHash} from 'crypto';
 import {CompressionType, Document, Metadata, MetadataValue} from './document';
 import {SecurityIdentityBuilder} from './securityIdentityBuilder';
 
@@ -227,12 +228,18 @@ export class DocumentBuilder {
 
   private validateAndFillMissing() {
     // TODO: validation that cannot be performed on a single property, but requires looking at multiple property at the same time.
-    // For example, if there's no permanentID set, we want to generate one using the document URI.
     // or validate that we don't have both `data` AND `compressedBinaryData`.
     // Could also use https://www.npmjs.com/package/@coveo/bueno to validate schema (useful for pure JS users).
+    if (!this.doc.permanentId) {
+      this.doc.permanentId = this.generatePermanentId();
+    }
     return;
   }
 
+  private generatePermanentId() {
+    return createHash('sha256').update(this.doc.uri).digest('hex');
+  }
+
   private validateDateAndReturnValidDate(d: Date | string | number) {
     const validatedDate = dayjs(d);
     return validatedDate.toISOString();
@@ -243,7 +250,10 @@ export class DocumentBuilder {
     permissionSection: 'allowedPermissions' | 'deniedPermissions'
   ) {
     const identities = securityIdentityBuilder.build();
-      this.doc.permissions![permissionSection] = [].concat(identities);
+    if (Array.isArray(identities)) {
+      this.doc.permissions![permissionSection] = identities;
+    } else {
+      this.doc.permissions![permissionSection] = [identities];
     }
   }
 }