Allow @ sign in @server_default annotation (#5664) (#5673)

* Allow @ sign in @server_default annotation

* Fix lint

* Run make contrib

(cherry picked from commit 469fd6b)

Co-authored-by: Quentin Pradet <quentin.pradet@elastic.co>

Author: github-actions[bot]

compiler/src/model/utils.ts

@@ -877,6 +877,11 @@ function hoistPropertyAnnotations (property: model.Property, jsDocs: JSDoc[]): v
         assert(jsDocs, Array.isArray(value), 'The default value should be an array')
         property.serverDefault = value
       } else {
+        // JSDoc prevents literal @ in values, but the at sign can be escaped
+        if (value.startsWith('\\@')) {
+          value = value.replace('\\@', '@')
+        }
+
         switch (property.type.type.name) {
           case 'boolean':
             assert(jsDocs, value === 'true' || value === 'false', `The default value for ${property.name} should be a boolean`)

docs/modeling-guide.md

@@ -601,6 +601,18 @@ class Foo {
 }
 ```
 
+If you need an `@` sign, you can escape it:
+
+```ts
+class Foo {
+  /**
+   * Field containing event timestamp.
+   * @server_default \@timestamp
+   */
+  timestamp_field?: Field
+}
+```
+
 #### `@doc_id`
 
 An identifier that can be used for generating the doc url in clients.

output/openapi/elasticsearch-openapi.json

@@ -120,7 +120,8 @@ export interface Request extends RequestBase {
      */
     tiebreaker_field?: Field
     /**
-     * Field containing event timestamp. Default "@timestamp"
+     * Field containing event timestamp.
+     * @server_default \@timestamp
      */
     timestamp_field?: Field
     /**

output/openapi/elasticsearch-serverless-openapi.json

@@ -789,7 +789,7 @@ export class DateProcessor extends ProcessorBase {
   locale?: string
   /**
    * The field that will hold the parsed date.
-   * @server_default `@timestamp`
+   * @server_default \@timestamp
    */
   target_field?: Field
   /**