tests/vectors: add github_forgesource_branch

tests/vectors.yaml

@@ -32,6 +32,20 @@ _anchors:
     - repo
     - scm
     - forge
+  zeroidx_branch: &zeroidx_branch
+    - branch
+    - distprefix
+    - _forgeversionsuffix
+    - forgesource
+    - forgesetupargs
+    - archivename
+    - archiveext
+    - archiveurl
+    - topdir
+    - extractdir
+    - repo
+    - scm
+    - forge
 
 cases:
   - id: smoke
@@ -119,6 +133,24 @@ cases:
       forge: github
     zero_indexed: *zeroidx_commit
 
+  - id: github_forgesource_branch
+    defines:
+      forgeurl: "https://github.com/ansible/ansible"
+      branch: main
+    expected:
+      forgesource: "%{forgeurl}/archive/main/ansible-main.tar.gz"
+      forgesetupargs: "-n ansible-main"
+      archivename: "ansible-main"
+      archiveext: "tar.gz"
+      archiveurl: "%{forgesource}"
+      topdir: "ansible-main"
+      extractdir: "ansible-main"
+      repo: ansible
+      scm: git
+      distprefix: ".gitmain"
+      forge: github
+    zero_indexed: *zeroidx_branch
+
     # Different semantics are used when a date is specified
   - id: github_forgesource_commit_with_date
     defines: