feat(browse): add :Jbrowse to open current file on remote (#89)

lua/jj/browse.lua

@@ -0,0 +1,168 @@
+--- @class jj.cmd.browse
+local M = {}
+
+local utils = require("jj.utils")
+
+--- Build a line anchor for a hosted-file URL.
+--- GitHub uses `#L<start>-L<end>` for ranges; GitLab uses `#L<start>-<end>`.
+--- @param host string|nil Remote host name (e.g. github.com)
+--- @param line1 integer|nil 1-indexed start line
+--- @param line2 integer|nil 1-indexed end line
+--- @return string anchor URL fragment (including leading `#`), or empty string
+local function build_anchor(host, line1, line2)
+	if not line1 then
+		return ""
+	end
+
+	-- GitHub: #L1-L2, GitLab: #L1-2
+	local is_gitlab = host and host:match("gitlab")
+	if line2 and line2 ~= line1 then
+		if is_gitlab then
+			return string.format("#L%d-%d", line1, line2)
+		end
+		return string.format("#L%d-L%d", line1, line2)
+	end
+
+	return string.format("#L%d", line1)
+end
+
+--- Build a browser URL for a file in a repo.
+--- Falls back to GitHub-style routing unless host is recognized.
+--- @param base_repo_url string HTTPS base repo URL (e.g. https://host/owner/repo)
+--- @param host string Remote hostname
+--- @param ref string Commit SHA (preferred) or branch-like reference
+--- @param path string Repo-relative file path
+--- @param line1 integer|nil 1-indexed start line
+--- @param line2 integer|nil 1-indexed end line
+--- @return string url
+local function build_browse_url(base_repo_url, host, ref, path, line1, line2)
+	local encoded_path = utils.url_encode_path(path)
+	local anchor = build_anchor(host, line1, line2)
+
+	if host and host:match("gitlab") then
+		return string.format("%s/-/blob/%s/%s%s", base_repo_url, ref, encoded_path, anchor)
+	end
+
+	if host and (host:match("gitea") or host:match("forgejo")) then
+		-- Use commit URLs only when ref looks like a SHA; otherwise use branch URLs.
+		local is_sha = type(ref) == "string" and ref:match("^[0-9a-fA-F]+$") and #ref >= 7
+		local kind = is_sha and "commit" or "branch"
+		return string.format("%s/src/%s/%s/%s%s", base_repo_url, kind, ref, encoded_path, anchor)
+	end
+
+	-- GitHub-style default
+	return string.format("%s/blob/%s/%s%s", base_repo_url, ref, encoded_path, anchor)
+end
+
+--- Open current file on remote at current line / selected range
+--- @param opts? {line1?: number, line2?: number, range?: number, args?: string, fargs?: string[]}
+function M.browse(opts)
+	if not utils.ensure_jj() then
+		return
+	end
+
+	local abs_path = vim.api.nvim_buf_get_name(0)
+	if not utils.is_file(abs_path) then
+		utils.notify("Current buffer is not a file", vim.log.levels.ERROR)
+		return
+	end
+
+	local root = utils.get_jj_root()
+	if not root then
+		utils.notify("Not in a jj repository", vim.log.levels.ERROR)
+		return
+	end
+
+	local repo_rel = utils.relpath(root, abs_path)
+	if not repo_rel then
+		utils.notify("File is not within jj repository root", vim.log.levels.ERROR)
+		return
+	end
+	repo_rel = repo_rel:gsub("\\", "/")
+
+	local line1, line2
+	if opts and opts.range and opts.range > 0 and opts.line1 and opts.line2 then
+		line1, line2 = opts.line1, opts.line2
+	else
+		line1 = vim.api.nvim_win_get_cursor(0)[1]
+		line2 = line1
+	end
+
+	local revset = "@"
+	if opts then
+		if type(opts.args) == "string" and opts.args ~= "" then
+			revset = vim.trim(opts.args)
+		elseif type(opts.fargs) == "table" and #opts.fargs > 0 then
+			revset = vim.trim(opts.fargs[1] or "")
+		end
+	end
+
+	local remotes = utils.get_remotes()
+	if remotes == nil then
+		utils.notify("Failed to get git remotes", vim.log.levels.ERROR)
+		return
+	end
+	if #remotes == 0 then
+		utils.notify("No git remotes found", vim.log.levels.ERROR)
+		return
+	end
+
+	local function browse_with_remote(remote)
+		local base_repo_url, host = utils.normalize_remote_url(remote.url)
+		if not base_repo_url or not host then
+			utils.notify("Unsupported remote URL: " .. (remote.url or ""), vim.log.levels.ERROR)
+			return
+		end
+
+		-- If a revset has been given the walkback is none since the user doesn't expect any walkback
+		local max_walkback = 20
+		if revset ~= "@" then
+			max_walkback = 0
+		end
+
+		local commit_id = utils.get_pushed_commit_id(revset, remote.name, max_walkback)
+		if not commit_id then
+			utils.notify(
+				string.format("Could not determine a remote reachable commit for %s", revset),
+				vim.log.levels.ERROR
+			)
+			return
+		end
+
+		-- Prefer a single remote bookmark name (more readable). If there are multiple,
+		-- stick to commit SHA to avoid ambiguity.
+		local ref = utils.get_unique_remote_bookmark_name(commit_id, remote.name) or commit_id
+
+		local url = build_browse_url(base_repo_url, host, ref, repo_rel, line1, line2)
+		utils.open_url(url)
+		utils.notify("Opening in browser", vim.log.levels.INFO, 1000)
+	end
+
+	if #remotes == 1 then
+		browse_with_remote(remotes[1])
+		return
+	end
+
+	vim.ui.select(remotes, {
+		prompt = "Select remote to browse: ",
+		format_item = function(item)
+			return string.format("%s (%s)", item.name, item.url)
+		end,
+	}, function(choice)
+		if choice then
+			browse_with_remote(choice)
+		end
+	end)
+end
+
+function M.register_command()
+	vim.api.nvim_create_user_command("Jbrowse", function(cmdopts)
+		M.browse(cmdopts)
+	end, {
+		nargs = "?",
+		range = true,
+		desc = "Open current file on remote (optionally pass revset; supports visual line range)",
+	})
+end
+
+return M