support main branch by checking for default branch

grosser · Jul 2, 2024 · b2e50b7 · b2e50b7
1 parent 1d69626
commit b2e50b7
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Showing 2 changed files with 31 additions and 5 deletions.
diff --git a/lib/git/whence.rb b/lib/git/whence.rb
@@ -4,6 +4,7 @@
 module Git::Whence
   module CLI
     SQUASH_REGEX = /\(#(\d+)\)$/
+    DEFAULT_BRANCHES = ["main", "master"]
 
     class << self
       def run(argv)
@@ -66,8 +67,8 @@ def origin
       def find_merge(commit)
         merge_commit, merge = (
           find_merge_simple(commit, "HEAD") ||
-          find_merge_simple(commit, "master") ||
-          find_merge_fuzzy(commit, "master")
+          find_merge_simple(commit, default_branch) ||
+          find_merge_fuzzy(commit, default_branch)
         )
 
         if merge && merge_include_commit?(merge, merge_commit)
@@ -83,11 +84,29 @@ def merge_include_commit?(merge, commit)
       end
 
       def find_merge_fuzzy(commit, branch)
-        if similar = find_similar(commit, branch)
+        if (similar = find_similar(commit, branch))
           find_merge_simple(similar, branch)
         end
       end
 
+      def default_branch
+        @default_branch ||= remote_default_branch || local_default_branch
+      end
+
+      def remote_default_branch
+        remotes = sh("git remote").split("\n")
+        return nil if remotes.empty?
+        preferred = (remotes.include?("origin") ? "origin" : remotes.first)
+        folder = ".git/refs/remotes/#{preferred}"
+        (Dir["#{folder}/*"].map { |f| f.sub("#{folder}/", "") } & DEFAULT_BRANCHES).sort.first
+      end
+
+      # guess default branch by last changed commonly used default branch or current branch
+      def local_default_branch
+        branches = sh("git branch --sort=-committerdate").split("\n").map { |br| br.split(" ").last }
+        (branches & DEFAULT_BRANCHES).first || sh("git symbolic-ref HEAD").strip.sub("refs/heads/", "")
+      end
+
       def find_squash_merge(commit)
         commit if sh("git show -s --format='%s' #{commit}") =~ SQUASH_REGEX
       end
@@ -98,7 +117,7 @@ def find_similar(commit, branch)
         time = time.to_i
         same = sh("git log #{branch} --pretty=format:'%H %an %s' --before #{time + month} --after #{time - month}")
         found = same.split("\n").map { |x| x.split(" ", 2) }.detect { |_, message| message == search }
-        found && found.first
+        found&.first
       end
 
       def find_merge_simple(commit, branch)

diff --git a/test/git/whence_test.rb b/test/git/whence_test.rb
@@ -102,6 +102,13 @@
         whence(commit).must_equal "#{merge[0...7]} Merge branch 'foobar'\n"
       end
 
+      it "finds on non-default branch" do
+        init_git
+        sh("git co -b main")
+        merge, commit = add_merge
+        whence(commit).must_equal "#{merge[0...7]} Merge branch 'foobar'\n"
+      end
+
       it "fails with a mainline commit" do
         init_git
         3.times { |i| sh("echo #{i} > xxx && git commit -am 'xxx#{i}'") }
@@ -172,7 +179,7 @@ def init_git
 
   # return merge commit and merged commit
   def add_merge(options={})
-    if message = options[:message]
+    if (message = options[:message])
       message = "-m '#{message}'"
     end
     branch = options[:branch] || "foobar"