fix: support git remotes other than 'origin' (#97)

Author: mrcjkb

lua/rocks-git/git.lua

@@ -234,12 +234,15 @@ end
 ---@return string | nil head The remote HEAD branch name
 function git.get_head_branch(pkg)
     local git_dir = vim.fs.joinpath(pkg.dir, ".git")
-    local remote_head_ref = read_line(vim.fs.joinpath(git_dir, "refs", "remotes", "origin", "HEAD"))
-    if not remote_head_ref then
-        return
-    end
-    remote_head_ref = remote_head_ref:gsub("ref: refs/remotes/origin/", "")
-    return remote_head_ref
+    local remotes_dir = vim.fs.joinpath(git_dir, "refs", "remotes")
+    local remotes = vim.fn.globpath(remotes_dir, "*", false, true)
+    return vim.iter(remotes)
+        :map(function(remote_dir)
+            return read_line(vim.fs.joinpath(remote_dir, "HEAD"))
+        end)
+        :find(function(head_file_content)
+            return head_file_content:gsub("ref: refs/remotes/.+/", "")
+        end)
 end
 
 ---@param url string

spec/git_spec.lua

@@ -0,0 +1,37 @@
+local git = require("rocks-git.git")
+
+local origin_pkg_dir = vim.fn.tempname()
+local origin_pkg_remote_dir = vim.fs.joinpath(origin_pkg_dir, ".git", "refs", "remotes", "origin")
+
+local upstream_pkg_dir = vim.fn.tempname()
+local upstream_pkg_remote_dir = vim.fs.joinpath(upstream_pkg_dir, ".git", "refs", "remotes", "upstream")
+
+setup(function()
+    vim.system({ "mkdir", "-p", origin_pkg_remote_dir }, {}):wait()
+    vim.system({ "mkdir", "-p", upstream_pkg_remote_dir }, {}):wait()
+    local origin_head = vim.fs.joinpath(origin_pkg_remote_dir, "HEAD")
+    local fd = assert(io.open(origin_head, "w"), "could not open " .. origin_head)
+    fd:write("foo")
+    fd:close()
+    local upstream_head = vim.fs.joinpath(upstream_pkg_remote_dir, "HEAD")
+    fd = assert(io.open(upstream_head, "w"), "could not open " .. upstream_head)
+    fd:write("bar")
+    fd:close()
+end)
+
+describe("git", function()
+    it("Can get head branch from 'origin' remote", function()
+        local head_branch = git.get_head_branch({
+            dir = origin_pkg_dir,
+            url = "https://github.com/lumen-oss/luarocks-stub.git",
+        })
+        assert.Same("foo", head_branch)
+    end)
+    it("Can get head branch from 'upstream' remote", function()
+        local head_branch = git.get_head_branch({
+            dir = upstream_pkg_dir,
+            url = "https://github.com/lumen-oss/luarocks-stub.git",
+        })
+        assert.Same("bar", head_branch)
+    end)
+end)