Add refspecs trait for github SCM

Change-Id: Ibdcd5621fa1d030cda26f29cadb3ae4c3c3f3704
Signed-off-by: Anna Tikhonova <anna.m.tikhonova@gmail.com>

jenkins_jobs/modules/project_multibranch.py

@@ -930,6 +930,7 @@ def github_scm(xml_parent, data):
             notifications on pull requests (default false) (Requires the
             :jenkins-plugins:`GitHub Branch Source Plugin
             <disable-github-multibranch-status>`.)
+        * **refspecs** (`list(str)`): Which refspecs to fetch.
         * **submodule** (`dict`)
             * **disable** (`bool`) - By disabling support for submodules you
               can still keep using basic git plugin functionality and just have
@@ -1085,6 +1086,24 @@ def github_scm(xml_parent, data):
     # - use-author
     git_extensions(traits, data)
 
+    if data.get("refspecs"):
+        refspec_trait = XML.SubElement(
+            traits,
+            "jenkins.plugins.git.traits.RefSpecsSCMSourceTrait",
+            {"plugin": "git"},
+        )
+        templates = XML.SubElement(refspec_trait, "templates")
+        refspecs = data.get("refspecs")
+        for refspec in refspecs:
+            e = XML.SubElement(
+                templates,
+                (
+                    "jenkins.plugins.git.traits"
+                    ".RefSpecsSCMSourceTrait_-RefSpecTemplate"
+                ),
+            )
+            XML.SubElement(e, "value").text = refspec
+
     # github-only extensions
     disable_github_status_path_dscore = (
         "com.adobe.jenkins.disable__github__multibranch__status"

tests/multibranch/fixtures/scm_github_full.xml

@@ -103,6 +103,13 @@
             <jenkins.plugins.git.traits.AuthorInChangelogTrait>
               <extension class="hudson.plugins.git.extensions.impl.AuthorInChangelog"/>
             </jenkins.plugins.git.traits.AuthorInChangelogTrait>
+            <jenkins.plugins.git.traits.RefSpecsSCMSourceTrait plugin="git">
+              <templates>
+                <jenkins.plugins.git.traits.RefSpecsSCMSourceTrait_-RefSpecTemplate>
+                  <value>+refs/heads/*:refs/remotes/@{remote}/*</value>
+                </jenkins.plugins.git.traits.RefSpecsSCMSourceTrait_-RefSpecTemplate>
+              </templates>
+            </jenkins.plugins.git.traits.RefSpecsSCMSourceTrait>
             <com.adobe.jenkins.disable__github__multibranch__status.DisableStatusUpdateTrait plugin="disable-github-multibranch-status"/>
           </traits>
         </source>

tests/multibranch/fixtures/scm_github_full.yaml

@@ -66,6 +66,8 @@ scm:
         depth: 3
         do-not-fetch-tags: true
         disable-pr-notifications: true
+        refspecs:
+          - '+refs/heads/*:refs/remotes/@{remote}/*'
         submodule:
             disable: false
             recursive: true