Merge pull request #19674 from Snuffleupagus/core-document-more-async

Introduce more `async` code in the `src/core/document.js` file

src/core/document.js

@@ -251,8 +251,9 @@ class Page {
   /**
    * @returns {Promise<BaseStream>}
    */
-  getContentStream() {
-    return this.pdfManager.ensure(this, "content").then(content => {
+  async getContentStream() {
+    const content = await this.pdfManager.ensure(this, "content");
+
     if (content instanceof BaseStream) {
       return content;
     }
@@ -264,7 +265,6 @@ class Page {
     }
     // Replace non-existent page content with empty content.
     return new NullStream();
-    });
   }
 
   get xfaData() {
@@ -375,7 +375,7 @@ class Page {
     }
   }
 
-  save(handler, task, annotationStorage, changes) {
+  async save(handler, task, annotationStorage, changes) {
     const partialEvaluator = new PartialEvaluator({
       xref: this.xref,
       handler,
@@ -392,7 +392,8 @@ class Page {
 
     // Fetch the page's annotations and save the content
     // in case of interactive form fields.
-    return this._parsedAnnotations.then(function (annotations) {
+    const annotations = await this._parsedAnnotations;
+
     const promises = [];
     for (const annotation of annotations) {
       promises.push(
@@ -407,22 +408,18 @@ class Page {
           })
       );
     }
-
     return Promise.all(promises);
-    });
   }
 
-  loadResources(keys) {
+  async loadResources(keys) {
     // TODO: add async `_getInheritableProperty` and remove this.
-    this.resourcesPromise ||= this.pdfManager.ensure(this, "resources");
+    await (this.resourcesPromise ??= this.pdfManager.ensure(this, "resources"));
 
-    return this.resourcesPromise.then(() => {
     const objectLoader = new ObjectLoader(this.resources, keys, this.xref);
-      return objectLoader.load();
-    });
+    await objectLoader.load();
   }
 
-  getOperatorList({
+  async getOperatorList({
     handler,
     sink,
     task,
@@ -527,7 +524,7 @@ class Page {
     const pageListPromise = Promise.all([
       contentStreamPromise,
       resourcesPromise,
-    ]).then(([contentStream]) => {
+    ]).then(async ([contentStream]) => {
       const opList = new OperatorList(intent, sink);
 
       handler.send("StartRenderPage", {
@@ -539,27 +536,27 @@ class Page {
         cacheKey,
       });
 
-      return partialEvaluator
-        .getOperatorList({
+      await partialEvaluator.getOperatorList({
         stream: contentStream,
         task,
         resources: this.resources,
         operatorList: opList,
-        })
-        .then(() => opList);
+      });
+      return opList;
     });
 
     // Fetch the page's annotations and add their operator lists to the
     // page's operator list to render them.
-    return Promise.all([
+    // eslint-disable-next-line prefer-const
+    let [pageOpList, annotations, newAnnotations] = await Promise.all([
       pageListPromise,
       this._parsedAnnotations,
       newAnnotationsPromise,
-    ]).then(function ([pageOpList, annotations, newAnnotations]) {
+    ]);
+
     if (newAnnotations) {
       // Some annotations can already exist (if it has the refToReplace
-        // property). In this case, we replace the old annotation by the new
-        // one.
+      // property). In this case, we replace the old annotation by the new one.
       annotations = annotations.filter(
         a => !(a.ref && deletedAnnotations.has(a.ref))
       );
@@ -604,12 +601,7 @@ class Page {
       ) {
         opListPromises.push(
           annotation
-              .getOperatorList(
-                partialEvaluator,
-                task,
-                intent,
-                annotationStorage
-              )
+            .getOperatorList(partialEvaluator, task, intent, annotationStorage)
             .catch(function (reason) {
               warn(
                 "getOperatorList - ignoring annotation data during " +
@@ -625,7 +617,7 @@ class Page {
       }
     }
 
-      return Promise.all(opListPromises).then(function (opLists) {
+    const opLists = await Promise.all(opListPromises);
     let form = false,
       canvas = false;
 
@@ -640,8 +632,6 @@ class Page {
       /* separateAnnots = */ { form, canvas }
     );
     return { length: pageOpList.totalLength };
-      });
-    });
   }
 
   async extractTextContent({