Add cookie value 'dotcom_user' to events (#54032)

Author: heiskr

Diff for: src/events/lib/schema.ts

@@ -106,6 +106,10 @@ const context = {
       type: 'boolean',
       description: 'Anonymous -- whether the user has github.com cookies set.',
     },
+    dotcom_user: {
+      type: 'string',
+      description: 'The cookie value of dotcom_user',
+    },
 
     // Device information
     os: {

Diff for: src/events/middleware.ts

@@ -52,7 +52,7 @@ router.post(
 
     // Validate the data matches the corresponding data schema
     const validate = validators[type]
-    if (!validate(req.body)) {
+    if (!validate(body)) {
       // This protects so we don't bother sending the same validation
       // error, per user, more than once (per time interval).
       // This helps if we're bombarded with junk bot traffic. So it
@@ -84,6 +84,10 @@ router.post(
       body.survey_comment_language = await getGuessedLanguage(body.survey_comment)
     }
 
+    // Add dotcom_user to the context if it's available
+    // JSON.stringify removes `undefined` values but not `null`, and we don't want to send `null` to Hydro
+    body.context.dotcom_user = req.cookies?.dotcom_user ? req.cookies.dotcom_user : undefined
+
     await publish({
       schema: hydroNames[type],
       value: omit(body, OMIT_FIELDS),

Diff for: src/events/types.ts

@@ -34,6 +34,7 @@ export type EventProps = {
     path_type: string
     status: number
     is_logged_in: boolean
+    dotcom_user: string
     os: string
     os_version: string
     browser: string