Fix: Apply schema defaults to build output (fixes #182) (#183)

Author: taylortom

lib/AdaptFrameworkBuild.js

@@ -211,6 +211,7 @@ class AdaptFrameworkBuild {
 
     await this.preBuildHook.invoke(this)
 
+    await this.applySchemaDefaults()
     await this.writeContentJson()
 
     logDir('courseDir', this.courseDir)
@@ -425,6 +426,60 @@ class AdaptFrameworkBuild {
     }))
   }
 
+  /**
+   * Applies schema defaults to the in-memory course and config data using
+   * the jsonschema module. Replicates what grunt's schema-defaults task does.
+   *
+   * TODO: replace validateWithDefaults workaround with schema.validate(data, { ignoreErrors: true })
+   * once migrated to adapt-schemas v3.x (see #184)
+   * @return {Promise}
+   */
+  async applySchemaDefaults () {
+    const [jsonschema, contentplugin] = await App.instance.waitForModule('jsonschema', 'contentplugin')
+
+    const enabledPluginSchemas = this.enabledPlugins
+      .reduce((m, p) => [...m, ...contentplugin.getPluginSchemas(p.name)], [])
+    const extensionFilter = s => contentplugin.isPluginSchema(s) ? enabledPluginSchemas.includes(s) : true
+    const getSchema = name => jsonschema.getSchema(name, { useCache: false, extensionFilter })
+
+    /**
+     * Applies defaults via validate(), catching and ignoring validation errors.
+     * The validated+defaulted data is returned from validate() on success, or
+     * extracted from the error on failure (validate clones internally).
+     */
+    const validateWithDefaults = (schema, data) => {
+      try {
+        return schema.validate(data, { useDefaults: true, ignoreRequired: true })
+      } catch (e) {
+        return e.data.data
+      }
+    }
+
+    const [courseSchema, configSchema] = await Promise.all([
+      getSchema('course'),
+      getSchema('config')
+    ])
+    Object.assign(this.courseData.course.data, validateWithDefaults(courseSchema, this.courseData.course.data))
+    Object.assign(this.courseData.config.data, validateWithDefaults(configSchema, this.courseData.config.data))
+
+    for (const type of ['contentObject', 'article', 'block']) {
+      const schemaName = type === 'contentObject' ? 'contentobject' : type
+      const schema = await getSchema(schemaName)
+      for (const item of this.courseData[type].data) {
+        Object.assign(item, validateWithDefaults(schema, item))
+      }
+    }
+
+    const componentSchemas = {}
+    for (const item of this.courseData.component.data) {
+      const schemaName = `${item._component}-component`
+      if (!componentSchemas[schemaName]) {
+        componentSchemas[schemaName] = await getSchema(schemaName)
+      }
+      Object.assign(item, validateWithDefaults(componentSchemas[schemaName], item))
+    }
+  }
+
   /**
    * Outputs all course data to the required JSON files
    * @return {Promise}