Fix many bugs and make things actually work

3 files changed, 495 insertions, 206 deletions

diff --git a/lua/dep.lua b/lua/dep.lua
index 8078b62..30e01d4 100644
--- a/lua/dep.lua
+++ b/lua/dep.lua
@@ -3,21 +3,44 @@ local proc = require("dep/proc")
 
 logger:open()
 
-local base_dir
+local initialized, config_path, base_dir
 local packages, package_roots
 
-local function register(arg)
-  if type(arg) ~= "table" then
-    arg = { arg }
+local function get_name(id)
+  local name = id:match("^[%w-_.]+/([%w-_.]+)$")
+  if name then
+    return name
+  else
+    error(string.format('invalid name "%s"; must be in the format "user/package"', id))
+  end
+end
+
+local function link_dependency(parent, child)
+  if not parent.dependents[child.id] then
+    parent.dependents[child.id] = child
+    parent.dependents[#parent.dependents + 1] = child
+  end
+
+  if not child.dependencies[parent.id] then
+    child.dependencies[parent.id], child.root = parent, false
+    child.dependencies[#child.dependencies + 1] = parent
+  end
+end
+
+local function register(spec, overrides)
+  overrides = overrides or {}
+
+  if type(spec) ~= "table" then
+    spec = { spec }
   end
 
-  local id = arg[1]
+  local id = spec[1]
   local package = packages[id]
 
   if not package then
     package = {
       id = id,
-      enabled = false,
+      enabled = true,
       exists = false,
       added = false,
       configured = false,
@@ -31,51 +54,96 @@ local function register(arg)
     }
 
     packages[id] = package
+    packages[#packages + 1] = package
   end
 
   local prev_dir = package.dir -- optimization
 
   -- meta
-  package.name = arg.as or package.name or id:match("^[%w-_.]+/([%w-_.]+)$")
-  package.url = arg.url or package.url or ("https://github.com/" .. id .. ".git")
-  package.branch = arg.branch or package.branch
+  package.name = spec.as or package.name or get_name(id)
+  package.url = spec.url or package.url or ("https://github.com/" .. id .. ".git")
+  package.branch = spec.branch or package.branch
   package.dir = base_dir .. package.name
-  package.pin = arg.pin or package.pin
-  package.enabled = not arg.disabled and package.enabled
+  package.pin = overrides.pin or spec.pin or package.pin
+  package.enabled = not overrides.disable and not spec.disable and package.enabled
 
   if prev_dir ~= package.dir then
     package.exists = vim.fn.isdirectory(package.dir) ~= 0
     package.configured = package.exists
   end
 
-  table.insert(package.on_setup, arg.setup)
-  table.insert(package.on_config, arg.config)
-  table.insert(package.on_load, arg[2])
+  package.on_setup[#package.on_setup + 1] = spec.setup
+  package.on_config[#package.on_config + 1] = spec.config
+  package.on_load[#package.on_load + 1] = spec[2]
 
-  for _, req in ipairs(type(arg.requires) == "table" and arg.requires or { arg.requires }) do
-    local parent, child = register(req), package
-    parent.dependents[child.id] = child
-    child.dependencies[parent.id], child.root = parent, false
+  if type(spec.requires) == "table" then
+    for i = 1, #spec.requires do
+      link_dependency(register(spec.requires[i]), package)
+    end
+  elseif spec.requires then
+    link_dependency(register(spec.requires), package)
   end
 
-  for _, dep in ipairs(type(arg.deps) == "table" and arg.deps or { arg.deps }) do
-    local parent, child = package, register(dep)
-    parent.dependents[child.id] = child
-    child.dependencies[parent.id], child.root = parent, false
+  if type(spec.deps) == "table" then
+    for i = 1, #spec.deps do
+      link_dependency(package, register(spec.deps[i]))
+    end
+  elseif spec.deps then
+    link_dependency(package, register(spec.deps))
   end
+
+  return package
 end
 
-local function register_recursive(list)
-  for _, arg in ipairs(list) do
-    register(arg)
+local function register_recursive(list, overrides)
+  overrides = overrides or {}
+  overrides = {
+    pin = overrides.pin or list.pin,
+    disable = overrides.disable or list.disable,
+  }
+
+  for i = 1, #list do
+    local ok, err = pcall(register, list[i], overrides)
+    if not ok then
+      error(string.format("%s (spec=%s)", err, vim.inspect(list[i])))
+    end
   end
 
-  for _, module in ipairs(list.modules or {}) do
-    if type(module) == "string" then
-      module = require(module)
+  if list.modules then
+    for i = 1, #list.modules do
+      local name, module = "<unnamed module>", list.modules[i]
+
+      if type(module) == "string" then
+        name, module = module, require(module)
+      end
+
+      name = module.name or name
+
+      local ok, err = pcall(register_recursive, module, overrides)
+      if not ok then
+        error(string.format("%s <- %s", err, name))
+      end
     end
+  end
+end
+
+local function sort_dependencies()
+  local function compare(a, b)
+    local a_deps = #a.dependencies
+    local b_deps = #b.dependencies
 
-    register_recursive(module)
+    if a_deps == b_deps then
+      return a.id < b.id
+    else
+      return a_deps < b_deps
+    end
+  end
+
+  table.sort(packages, compare)
+
+  for i = 1, #packages do
+    table.sort(packages[i].dependencies, compare)
+    table.sort(packages[i].dependents, compare)
   end
 end
 
@@ -83,23 +151,25 @@ local function find_cycle()
   local index = 0
   local indexes = {}
   local lowlink = {}
-  local set = {}
   local stack = {}
 
+  -- use tarjan algorithm to find circular dependencies (strongly connected components)
   local function connect(package)
-    indexes[package.id], lowlink[package.id], set[package.id] = index, index, true
+    indexes[package.id], lowlink[package.id] = index, index
+    stack[#stack + 1], stack[package.id] = package, true
     index = index + 1
-    table.insert(stack, package)
 
-    for _, dependent in pairs(package.dependents) do
-      if indexes[dependent.id] == nil then
+    for i = 1, #package.dependents do
+      local dependent = package.dependents[i]
+
+      if not indexes[dependent.id] then
         local cycle = connect(dependent)
         if cycle then
           return cycle
         else
           lowlink[package.id] = math.min(lowlink[package.id], lowlink[dependent.id])
         end
-      elseif set[dependent.id] then
+      elseif stack[dependent.id] then
         lowlink[package.id] = math.min(lowlink[package.id], indexes[dependent.id])
       end
     end
@@ -109,20 +179,23 @@ local function find_cycle()
       local node
 
       repeat
-        node = table.remove(stack)
-        set[node.id] = nil
-        table.insert(cycle, node)
+        node = stack[#stack]
+        stack[#stack], stack[node.id] = nil, nil
+        cycle[#cycle + 1] = node
       until node == package
 
-      -- only consider multi-node components
-      if #cycle > 2 then
+      -- a node is by definition strongly connected to itself
+      -- ignore single-node components unless it explicitly specified itself as a dependency
+      if #cycle > 2 or package.dependents[package.id] then
         return cycle
       end
     end
   end
 
-  for _, package in pairs(packages) do
-    if indexes[package.id] == nil then
+  for i = 1, #packages do
+    local package = packages[i]
+
+    if not indexes[package.id] then
       local cycle = connect(package)
       if cycle then
         return cycle
@@ -131,22 +204,41 @@ local function find_cycle()
   end
 end
 
+local function ensure_acyclic()
+  local cycle = find_cycle()
+
+  if cycle then
+    local names = {}
+    for i = 1, #cycle do
+      names[i] = cycle[i].id
+    end
+    error("circular dependency detected in package graph: " .. table.concat(names, " -> "))
+  end
+end
+
 local function find_roots()
-  for _, package in pairs(packages) do
+  for i = 1, #packages do
+    local package = packages[i]
     if package.root then
-      table.insert(package_roots, package)
+      package_roots[#package_roots + 1] = package
     end
   end
 end
 
 local function run_hooks(package, type)
-  for _, cb in ipairs(package["on_" .. type]) do
-    local ok, err = pcall(cb)
+  local hooks = package[type]
+
+  for i = 1, #hooks do
+    local ok, err = pcall(hooks[i])
     if not ok then
       return false, err
     end
   end
 
+  if #hooks ~= 0 then
+    logger:log("hook", string.format("ran %d %s for %s", #hooks, #hooks == 1 and "hook" or "hooks", package.id))
+  end
+
   return true
 end
 
@@ -155,6 +247,7 @@ local function ensure_added(package)
     local ok, err = pcall(vim.cmd, "packadd " .. package.name)
     if ok then
       package.added = true
+      logger:log("vim", string.format("packadd completed for %s", package.id))
     else
       return false, err
     end
@@ -163,13 +256,21 @@ local function ensure_added(package)
   return true
 end
 
-local function configure_recursive(package, force)
+local function configure_recursive(package)
   if not package.exists or not package.enabled then
     return
   end
 
-  if not package.configured or force then
-    local ok, err = run_hooks(package, "setup")
+  for i = 1, #package.dependencies do
+    if not package.dependencies[i].configured then
+      return
+    end
+  end
+
+  local propagate = false
+
+  if not package.configured then
+    local ok, err = run_hooks(package, "on_setup")
     if not ok then
       logger:log("error", string.format("failed to set up %s; reason: %s", package.id, err))
       return
@@ -181,96 +282,128 @@ local function configure_recursive(package, force)
       return
     end
 
-    ok, err = run_hooks(package, "config")
+    ok, err = run_hooks(package, "on_config")
     if not ok then
       logger:log("error", string.format("failed to configure %s; reason: %s", package.id, err))
       return
     end
 
     package.configured, package.loaded = true, false
-    force = true
+    propagate = true
+
+    logger:log("config", string.format("configured %s", package.id))
   end
 
-  for _, dependent in pairs(package.dependents) do
-    configure_recursive(dependent, force)
+  for i = 1, #package.dependents do
+    local dependent = package.dependents[i]
+
+    dependent.configured = dependent.configured and not propagate
+    configure_recursive(dependent)
   end
 end
 
-local function load_recursive(package, force)
+local function load_recursive(package)
   if not package.exists or not package.enabled then
     return
   end
 
-  if not package.loaded or force then
+  for i = 1, #package.dependencies do
+    if not package.dependencies[i].loaded then
+      return
+    end
+  end
+
+  local propagate = false
+
+  if not package.loaded then
     local ok, err = ensure_added(package)
     if not ok then
       logger:log("error", string.format("failed to configure %s; reason: %s", package.id, err))
       return
     end
 
-    ok, err = run_hooks(package, "load")
+    ok, err = run_hooks(package, "on_load")
     if not ok then
       logger:log("error", string.format("failed to load %s; reason: %s", package.id, err))
       return
     end
 
     package.loaded = true
-    force = true
+    propagate = true
+
+    logger:log("load", string.format("loaded %s", package.id))
   end
 
-  for _, dependent in pairs(package.dependents) do
+  for i = 1, #package.dependents do
+    local dependent = package.dependents[i]
+
+    dependent.loaded = dependent.loaded and not propagate
     load_recursive(dependent, force)
   end
 end
 
 local function reload_meta()
-  vim.cmd([[
-    silent! helptags ALL
-    silent! UpdateRemotePlugins
-  ]])
+  local ok, err = pcall(
+    vim.cmd,
+    [[
+      silent! helptags ALL
+      silent! UpdateRemotePlugins
+    ]]
+  )
+
+  if ok then
+    logger:log("vim", "reloaded helptags and remote plugins")
+  else
+    logger:log("error", string.format("failed to reload helptags and remote plugins; reason: %s", err))
+  end
 end
 
 local function reload_all()
-  for _, package in pairs(package_roots) do
-    configure_recursive(package)
+  for i = 1, #package_roots do
+    configure_recursive(package_roots[i])
   end
 
-  for _, package in pairs(package_roots) do
-    load_recursive(package)
+  for i = 1, #package_roots do
+    load_recursive(package_roots[i])
   end
 
   reload_meta()
 end
 
 local function clean()
-  vim.loop.fs_scandir(base_dir, function(err, handle)
-    if err then
-      logger:log("error", string.format("failed to clean; reason: %s", err))
-    else
-      local queue = {}
+  vim.loop.fs_scandir(
+    base_dir,
+    vim.schedule_wrap(function(err, handle)
+      if err then
+        logger:log("error", string.format("failed to clean; reason: %s", err))
+      else
+        local queue = {}
 
-      while handle do
-        local name = vim.loop.fs_scandir_next(handle)
-        if name then
-          queue[name] = base_dir .. name
-        else
-          break
+        while handle do
+          local name = vim.loop.fs_scandir_next(handle)
+          if name then
+            queue[name] = base_dir .. name
+          else
+            break
+          end
         end
-      end
 
-      for _, package in pairs(packages) do
-        queue[package.name] = nil
-      end
+        for i = 1, #packages do
+          queue[packages[i].name] = nil
+        end
 
-      for name, dir in pairs(queue) do
-        -- todo: make this async
-        local ok = vim.fn.delete(dir, "rf")
-        if not ok then
-          logger:log("error", string.format("failed to delete %s", name))
+        for name, dir in pairs(queue) do
+          -- todo: make this async
+          local ok = vim.fn.delete(dir, "rf")
+          if ok then
+            logger:log("clean", string.format("deleted %s", name))
+          else
+            logger:log("error", string.format("failed to delete %s", name))
+          end
         end
       end
-    end
-  end)
+    end)
+  )
 end
 
 local function sync(package, cb)
@@ -283,34 +416,37 @@ local function sync(package, cb)
       return
     end
 
-    local function cb_err(err)
+    local function log_err(err)
       logger:log("error", string.format("failed to update %s; reason: %s", package.id, err))
-      cb(err)
     end
 
-    proc.git_current_commit(package.dir, function(err, before)
+    proc.git_rev_parse(package.dir, "HEAD", function(err, before)
       if err then
-        cb_err(before)
+        log_err(before)
+        cb(err)
       else
-        proc.git_fetch(package.dir, package.branch or "HEAD", function(err, message)
+        proc.git_fetch(package.dir, "origin", package.branch or "HEAD", function(err, message)
           if err then
-            cb_err(message)
+            log_err(message)
+            cb(err)
           else
-            proc.git_reset(package.dir, package.branch or "HEAD", function(err, message)
+            proc.git_rev_parse(package.dir, "FETCH_HEAD", function(err, after)
               if err then
-                cb_err(message)
+                log_err(after)
+                cb(err)
+              elseif before == after then
+                logger:log("skip", string.format("skipped %s", package.id))
+                cb(err)
               else
-                proc.get_current_commit(package.dir, function(err, after)
+                proc.git_reset(package.dir, after, function(err, message)
                   if err then
-                    cb_err(after)
+                    log_err(message)
                   else
-                    if before == after then
-                      logger:log("skip", string.format("skipped %s", package.id))
-                    else
-                      package.added, package.configured = false, false
-                      logger:log("update", string.format("updated %s", package.id))
-                    end
+                    package.added, package.configured = false, false
+                    logger:log("update", string.format("updated %s; %s -> %s", package.id, before, after))
                   end
+
+                  cb(err)
                 end)
               end
             end)
@@ -326,22 +462,146 @@ local function sync(package, cb)
         package.exists, package.added, package.configured = true, false, false
         logger:log("install", string.format("installed %s", package.id))
       end
+
+      cb(err)
     end)
   end
 end
 
 local function sync_list(list)
   local progress = 0
+  local has_errors = false
+
+  local function done(err)
+    progress = progress + 1
+    has_errors = has_errors or err
+
+    if progress == #list then
+      clean()
+      reload_all()
 
-  for _, package in ipairs(list) do
-    sync(package, function(err)
-      progress = progress + 1
-      if progress == #list then
-        clean()
-        reload_all()
+      if has_errors then
+        logger:log("error", "there were errors during sync; see :messages or :DepLog for more information")
       end
-    end)
+    end
+  end
+
+  for i = 1, #list do
+    sync(list[i], done)
+  end
+end
+
+local function print_list(list)
+  local window = vim.api.nvim_get_current_win()
+  local buffer = vim.api.nvim_create_buf(true, true)
+  local line = 0
+  local indent = 0
+
+  local function print(chunks)
+    local concat = {}
+    local column = 0
+
+    for i = 1, indent do
+      concat[#concat + 1] = "  "
+      column = column + 2
+    end
+
+    if not chunks then
+      chunks = {}
+    elseif type(chunks) == "string" then
+      chunks = { { chunks } }
+    end
+
+    for i = 1, #chunks do
+      local chunk = chunks[i]
+      concat[#concat + 1] = chunk[1]
+      chunk.offset, column = column, column + #chunk[1]
+    end
+
+    vim.api.nvim_buf_set_lines(buffer, line, -1, false, { table.concat(concat) })
+
+    for i = 1, #chunks do
+      local chunk = chunks[i]
+      if chunk[2] then
+        vim.api.nvim_buf_add_highlight(buffer, -1, chunk[2], line, chunk.offset, chunk.offset + #chunk[1])
+      end
+    end
+
+    line = line + 1
+  end
+
+  print("Installed packages:")
+  indent = 1
+
+  local loaded = {}
+
+  local function dry_load(package)
+    for i = 1, #package.dependencies do
+      if not loaded[package.dependencies[i].id] then
+        return
+      end
+    end
+
+    loaded[package.id] = true
+
+    local line = {
+      { "- ", "Comment" },
+      { package.id, "Underlined" },
+    }
+
+    if not package.exists then
+      line[#line + 1] = { " *not installed", "Comment" }
+    end
+
+    if not package.loaded then
+      line[#line + 1] = { " *not loaded", "Comment" }
+    end
+
+    if not package.enabled then
+      line[#line + 1] = { " *disabled", "Comment" }
+    end
+
+    if package.pin then
+      line[#line + 1] = { " *pinned", "Comment" }
+    end
+
+    print(line)
+
+    for i = 1, #package.dependents do
+      dry_load(package.dependents[i])
+    end
   end
+
+  for i = 1, #package_roots do
+    dry_load(package_roots[i])
+  end
+
+  indent = 0
+  print()
+  print("Dependency graph:")
+
+  local function walk_graph(package)
+    indent = indent + 1
+
+    print({
+      { "| ", "Comment" },
+      { package.id, "Underlined" },
+    })
+
+    for i = 1, #package.dependents do
+      walk_graph(package.dependents[i])
+    end
+
+    indent = indent - 1
+  end
+
+  for i = 1, #package_roots do
+    walk_graph(package_roots[i])
+  end
+
+  vim.api.nvim_buf_set_option(buffer, "bufhidden", "wipe")
+  vim.api.nvim_buf_set_option(buffer, "modifiable", false)
+  vim.api.nvim_win_set_buf(window, buffer)
 end
 
 vim.cmd([[
@@ -349,58 +609,77 @@ vim.cmd([[
   command! DepList lua require("dep").list()
   command! DepClean lua require("dep").clean()
   command! DepLog lua require("dep").open_log()
+  command! DepConfig lua require("dep").open_config()
 ]])
 
+local function wrap_api(name, fn)
+  return function(...)
+    if initialized then
+      local ok, err = pcall(fn, ...)
+      if not ok then
+        logger:log("error", err)
+      end
+    else
+      logger:log("error", string.format("cannot call %s; dep is not initialized", name))
+    end
+  end
+end
+
 --todo: prevent multiple execution of async routines
 return setmetatable({
-  sync = function()
-    local targets = {}
+  sync = wrap_api("dep.sync", function()
+    sync_list(packages)
+  end),
 
-    for _, package in pairs(packages) do
-      table.insert(targets, package)
-    end
+  list = wrap_api("dep.list", function()
+    print_list(packages)
+  end),
 
-    sync_list(targets)
-  end,
+  clean = wrap_api("dep.clean", clean),
 
-  open_log = function()
+  open_log = wrap_api("dep.open_log", function()
     vim.cmd("sp " .. logger.path)
-  end,
-}, {
-  __call = function(config)
-    base_dir = config.base_dir or (vim.fn.stdpath("data") .. "/site/pack/deps/start/")
-    packages, package_roots = {}, {}
+  end),
 
-    register_recursive({ "chiyadev/dep", modules = { config } })
-
-    local cycle = find_cycle()
-    if cycle then
-      local names = {}
-      for _, package in ipairs(cycle) do
-        table.insert(names, package.id)
+  open_config = wrap_api("dep.open_config", function()
+    vim.cmd("sp " .. config_path)
+  end),
+}, {
+  __call = function(self, config)
+    config_path = debug.getinfo(2, "S").source:sub(2)
+    initialized, err = pcall(function()
+      base_dir = config.base_dir or (vim.fn.stdpath("data") .. "/site/pack/deps/start/")
+      packages, package_roots = {}, {}
+
+      register("chiyadev/dep")
+      register_recursive(config)
+      sort_dependencies()
+      ensure_acyclic()
+      find_roots()
+      reload_all()
+
+      local should_sync = function(package)
+        if config.sync == "new" or config.sync == nil then
+          return not package.exists
+        else
+          return config.sync == "always"
+        end
       end
-      error("circular dependency detected in package graph: " .. table.concat(names, " -> "))
-    end
 
-    find_roots()
-    reload_all()
+      local targets = {}
 
-    local should_sync = function(package)
-      if config.sync == "new" or config.sync == nil then
-        return not package.exists
-      else
-        return config.sync == "always"
+      for i = 1, #packages do
+        local package = packages[i]
+        if should_sync(package) then
+          targets[#targets + 1] = package
+        end
       end
-    end
 
-    local targets = {}
+      sync_list(targets)
+    end)
 
-    for _, package in pairs(packages) do
-      if should_sync(package) then
-        table.insert(targets, package)
-      end
+    if not initialized then
+      logger:log("error", err)
     end
-
-    sync_list(targets)
   end,
 })
diff --git a/lua/dep/log.lua b/lua/dep/log.lua
index 915b214..e61e129 100644
--- a/lua/dep/log.lua
+++ b/lua/dep/log.lua
@@ -4,6 +4,8 @@ local logger = {
 }
 
 local colors = {
+  skip = "Constant",
+  clean = "Boolean",
   install = "MoreMsg",
   update = "WarningMsg",
   delete = "Directory",
@@ -32,28 +34,26 @@ function logger:close()
   end
 end
 
-function logger:log(op, message, cb)
-  if not self.silent and colors[op] then
-    vim.api.nvim_echo({
-      { "[dep]", "Identifier" },
-      { " " },
-      { message, colors[op] },
-    }, false, {})
-  end
-
-  if self.pipe then
-    local source = debug.getinfo(2, "Sl").short_src
-    local message = string.format("[%s] %s: %s\n", os.date(), source, message)
-
-    self.pipe:write(
-      message,
-      vim.schedule_wrap(function(err)
-        if cb then
-          cb(err)
-        end
-      end)
-    )
-  end
+function logger:log(op, message)
+  local source = debug.getinfo(2, "Sl").short_src
+
+  vim.schedule(function()
+    if type(message) ~= "string" then
+      message = vim.inspect(message)
+    end
+
+    if not self.silent and colors[op] then
+      vim.api.nvim_echo({
+        { "[dep]", "Identifier" },
+        { " " },
+        { message, colors[op] },
+      }, true, {})
+    end
+
+    if self.pipe then
+      self.pipe:write(string.format("[%s] %s: %s\n", os.date(), source, message))
+    end
+  end)
 end
 
 return logger
diff --git a/lua/dep/proc.lua b/lua/dep/proc.lua
index 38d91fe..376a98c 100644
--- a/lua/dep/proc.lua
+++ b/lua/dep/proc.lua
@@ -2,73 +2,83 @@ local logger = require("dep/log")
 local proc = {}
 
 function proc.exec(process, args, cwd, env, cb)
-  local out = vim.loop.new_pipe()
-  local buffer = {}
+  local handle, pid, buffer = nil, nil, {}
+  local stdout = vim.loop.new_pipe()
+  local stderr = vim.loop.new_pipe()
 
-  local handle = vim.loop.spawn(
+  handle, pid = vim.loop.spawn(
     process,
-    { args = args, cwd = cwd, env = env, stdio = { nil, out, out } },
+    { args = args, cwd = cwd, env = env, stdio = { nil, stdout, stderr } },
     vim.schedule_wrap(function(code)
       handle:close()
 
       local output = table.concat(buffer)
 
+      if output:sub(-1) == "\n" then
+        output = output:sub(1, -2)
+      end
+
       logger:log(
         process,
-        string.format('executed `%s` with args: "%s"\n%s', process, table.concat(args, '", "'), output)
+        string.format(
+          'executed `%s` (code=%s, pid=%s) with args: "%s"\n%s',
+          process,
+          code,
+          pid,
+          table.concat(args, '", "'),
+          output
+        )
       )
 
-      cb(code, output)
+      cb(code ~= 0, output)
     end)
   )
 
-  vim.loop.read_start(
-    out,
-    vim.schedule_wrap(function(_, data)
-      if data then
-        table.insert(buffer, data)
-      else
-        out:close()
-      end
-    end)
-  )
+  vim.loop.read_start(stdout, function(_, data)
+    if data then
+      buffer[#buffer + 1] = data
+    else
+      stdout:close()
+    end
+  end)
+
+  vim.loop.read_start(stderr, function(_, data)
+    if data then
+      buffer[#buffer + 1] = data
+    else
+      stderr:close()
+    end
+  end)
 end
 
 local git_env = { "GIT_TERMINAL_PROMPT=0" }
 
-function proc.git_current_commit(dir, cb)
-  exec("git", { "rev-parse", "HEAD" }, dir, git_env, cb)
+function proc.git_rev_parse(dir, arg, cb)
+  local args = { "rev-parse", "--short", arg }
+
+  proc.exec("git", args, dir, git_env, cb)
 end
 
 function proc.git_clone(dir, url, branch, cb)
-  local args = { "--depth=1", "--recurse-submodules", "--shallow-submodules", url, dir }
+  local args = { "clone", "--depth=1", "--recurse-submodules", "--shallow-submodules", url, dir }
 
   if branch then
-    table.insert(args, "--branch=" .. branch)
+    args[#args + 1] = "--branch=" .. branch
   end
 
-  exec("git", args, nil, git_env, cb)
+  proc.exec("git", args, nil, git_env, cb)
 end
 
-function proc.git_fetch(dir, branch, cb)
-  local args = { "--depth=1", "--recurse-submodules" }
+function proc.git_fetch(dir, remote, refspec, cb)
+  local args = { "fetch", "--depth=1", "--recurse-submodules", remote, refspec }
 
-  if branch then
-    table.insert(args, "origin")
-    table.insert(args, branch)
-  end
-
-  exec("git", args, dir, git_env, cb)
+  proc.exec("git", args, dir, git_env, cb)
 end
 
-function proc.git_reset(dir, branch, cb)
-  local args = { "--hard", "--recurse-submodules" }
-
-  if branch then
-    table.insert("origin/" .. branch)
-  end
+function proc.git_reset(dir, treeish, cb)
+  local args = { "reset", "--hard", "--recurse-submodules", treeish, "--" }
 
-  exec("git", args, dir, git_env, cb)
+  proc.exec("git", args, dir, git_env, cb)
 end
 
 return proc