fix(author): only override subclass undefined props

db/model/Gdoc/GdocAuthor.ts

@@ -9,6 +9,7 @@ import {
     DEFAULT_GDOC_FEATURED_IMAGE,
     OwidGdocBaseInterface,
     excludeNullish,
+    defaults,
 } from "@ourworldindata/utils"
 import { GdocBase } from "./GdocBase.js"
 import { htmlToEnrichedTextBlock } from "./htmlToEnriched.js"
@@ -26,9 +27,29 @@ export class GdocAuthor extends GdocBase implements OwidGdocAuthorInterface {
     }
 
     static create(obj: OwidGdocBaseInterface): GdocAuthor {
-        const gdoc = new GdocAuthor()
-        Object.assign(gdoc, obj)
-        return gdoc
+        const author = new GdocAuthor()
+
+        // We need to prevent obj methods from overriding GdocAuthor methods.
+        // This happens when createGdocAndInsertIntoDb() passes a GdocBase
+        // instance to loadGdocFromGdocBase(), instead of a simple object. In
+        // this case, simply assigning obj to gdoc would override GdocAuthor
+        // methods with GdocBase methods, in particular the
+        // _enrichedSubclassContent. When creating a new author,
+        // _enrichedSubclassContent would run from the base GdocBase class
+        // instead of the GdocAuthor subclass, and the socials block would not
+        // be shaped as an ArchieML block, thus throwing an error.
+        // Object.assign(gdoc, omitBy(obj, isFunction))
+
+        // However this approach still lets the parent class override properties
+        // of the subclass, which can be conceptually surprising.
+
+        // So instead, we choose to only override the properties and methods
+        // that are not defined in the subclass. Note that methods are also
+        // technically overriden if not defined on the subclass, although we can
+        // ignore it as this is redundant with inheritance mechanisms.
+        defaults(author, obj)
+
+        return author
     }
     protected typeSpecificFilenames(): string[] {
         return excludeNullish([this.content["featured-image"]])

packages/@ourworldindata/utils/src/Util.ts

@@ -7,6 +7,7 @@ import {
     compact,
     countBy,
     debounce,
+    defaults,
     difference,
     drop,
     dropRightWhile,
@@ -79,6 +80,7 @@ export {
     compact,
     countBy,
     debounce,
+    defaults,
     difference,
     drop,
     dropRightWhile,

packages/@ourworldindata/utils/src/index.ts

@@ -150,6 +150,7 @@ export {
     compact,
     countBy,
     debounce,
+    defaults,
     difference,
     drop,
     dropRightWhile,