feat(snapshot): make snapshot path more reliable on windows (#411)

This should fix windows as it does not rely on the shell to do an sha1

This should fix #404

Author: sudo-tee

README.md

@@ -123,6 +123,7 @@ require('opencode').setup({
   default_system_prompt = nil, -- Custom system prompt to use for all sessions. If nil, uses the default built-in system prompt
   keymap_prefix = '<leader>o', -- Default keymap prefix for global keymaps change to your preferred prefix and it will be applied to all keymaps starting with <leader>o
   opencode_executable = 'opencode', -- Name of your opencode binary
+  snapshot_path = nil, -- Override base path for the snapshot git directory (default: $XDG_DATA_HOME/opencode). Appends /snapshot/<project_id>/<worktree_hash>
 
   -- Server configuration for custom/external opencode servers
   server = {

lua/opencode/config.lua

@@ -301,6 +301,7 @@ M.defaults = {
   },
   prompt_guard = nil,
   child_readonly = true,
+  snapshot_path = nil,
   hooks = {
     on_file_edited = nil,
     on_session_loaded = nil,

lua/opencode/config_file.lua

@@ -1,4 +1,5 @@
 local Promise = require('opencode.promise')
+local sha1 = require('opencode.sha1')
 local M = {
   config_promise = nil,
   project_promise = nil,
@@ -40,30 +41,30 @@ M.get_opencode_project = Promise.async(function()
   return result --[[@as OpencodeProject|nil]]
 end)
 
----Compute SHA1 of a string (used to match opencode's Hash.fast for worktree path)
----@param str string
----@return string|nil
-local function sha1(str)
-  local result = vim.system({ 'sh', '-c', 'printf "%s" "$1" | sha1sum', '_', str }):wait()
-  if result and result.code == 0 then
-    return vim.trim(result.stdout):match('^(%x+)')
-  end
-end
-
 ---Get the snapshot storage path for the current workspace
+---Matches opencode's Global.Path.data + "snapshot" + projectId + Hash.fast(worktree)
+---Can be overridden via config.snapshot_path (base path, project_id and worktree_hash are appended)
 ---@type fun(): Promise<string>
 M.get_workspace_snapshot_path = Promise.async(function()
   local project = M.get_opencode_project():await() --[[@as OpencodeProject|nil]]
   if not project then
     return ''
   end
-  local home = vim.uv.os_homedir()
+  local data_home = require('opencode.config').snapshot_path
+  if not data_home or data_home == '' then
+    data_home = vim.uv.os_getenv('XDG_DATA_HOME')
+    if not data_home or data_home == '' then
+      data_home = vim.uv.os_homedir() .. '/.local/share'
+    end
+    data_home = vim.fs.joinpath(data_home, 'opencode')
+  end
   local cwd = vim.fn.getcwd()
   local worktree_hash = sha1(cwd)
   if not worktree_hash then
     return ''
   end
-  return home .. '/.local/share/opencode/snapshot/' .. project.id .. '/' .. worktree_hash
+  local path = vim.fs.joinpath(data_home, 'snapshot', project.id, worktree_hash)
+  return vim.fs.normalize(path)
 end)
 
 local _providers_render_callback = false

lua/opencode/sha1.lua

@@ -0,0 +1,93 @@
+local band = bit.band
+local bor = bit.bor
+local bxor = bit.bxor
+local bnot = bit.bnot
+local rol = bit.rol
+
+local function u32hex(n)
+  if n < 0 then
+    n = n + 4294967296
+  end
+  return string.format('%08x', n)
+end
+
+---@param str string
+---@return string|nil
+local function sha1(str)
+  local bytes = { string.byte(str, 1, #str) }
+  local bit_len = #bytes * 8
+
+  bytes[#bytes + 1] = 0x80
+  while (#bytes % 64) ~= 56 do
+    bytes[#bytes + 1] = 0
+  end
+
+  local bit_len_hi = math.floor(bit_len / 4294967296)
+  local bit_len_lo = bit_len % 4294967296
+
+  bytes[#bytes + 1] = math.floor(bit_len_hi / 16777216) % 256
+  bytes[#bytes + 1] = math.floor(bit_len_hi / 65536) % 256
+  bytes[#bytes + 1] = math.floor(bit_len_hi / 256) % 256
+  bytes[#bytes + 1] = band(bit_len_hi, 0x000000ff)
+  bytes[#bytes + 1] = math.floor(bit_len_lo / 16777216) % 256
+  bytes[#bytes + 1] = math.floor(bit_len_lo / 65536) % 256
+  bytes[#bytes + 1] = math.floor(bit_len_lo / 256) % 256
+  bytes[#bytes + 1] = band(bit_len_lo, 0x000000ff)
+
+  local h0 = 0x67452301
+  local h1 = 0xefcdab89
+  local h2 = 0x98badcfe
+  local h3 = 0x10325476
+  local h4 = 0xc3d2e1f0
+
+  for i = 1, #bytes, 64 do
+    local w = {}
+    for j = 1, 16 do
+      local k = i + (j - 1) * 4
+      w[j] = band(bytes[k] * 16777216 + bytes[k + 1] * 65536 + bytes[k + 2] * 256 + bytes[k + 3], 0xffffffff)
+    end
+    for j = 17, 80 do
+      w[j] = rol(bxor(bxor(w[j - 3], w[j - 8]), bxor(w[j - 14], w[j - 16])), 1)
+    end
+
+    local a = h0
+    local b = h1
+    local c = h2
+    local d = h3
+    local e = h4
+
+    for j = 1, 80 do
+      local f, k
+      if j <= 20 then
+        f = bor(band(b, c), band(bnot(b), d))
+        k = 0x5a827999
+      elseif j <= 40 then
+        f = bxor(bxor(b, c), d)
+        k = 0x6ed9eba1
+      elseif j <= 60 then
+        f = bor(bor(band(b, c), band(b, d)), band(c, d))
+        k = 0x8f1bbcdc
+      else
+        f = bxor(bxor(b, c), d)
+        k = 0xca62c1d6
+      end
+
+      local temp = band(rol(a, 5) + f + e + k + w[j], 0xffffffff)
+      e = d
+      d = c
+      c = rol(b, 30)
+      b = a
+      a = temp
+    end
+
+    h0 = band(h0 + a, 0xffffffff)
+    h1 = band(h1 + b, 0xffffffff)
+    h2 = band(h2 + c, 0xffffffff)
+    h3 = band(h3 + d, 0xffffffff)
+    h4 = band(h4 + e, 0xffffffff)
+  end
+
+  return u32hex(h0) .. u32hex(h1) .. u32hex(h2) .. u32hex(h3) .. u32hex(h4)
+end
+
+return sha1

lua/opencode/snapshot.lua

@@ -19,6 +19,7 @@ local function snapshot_git(cmd_args, opts)
   local cwd = vim.fn.getcwd()
   local args = { 'git', '--git-dir', snapshot_dir, '--work-tree', cwd }
   vim.list_extend(args, cmd_args)
+
   local result = vim.system(args, opts or { cwd = cwd }):wait()
   if result and result.code == 0 then
     return vim.trim(result.stdout), nil
@@ -172,6 +173,7 @@ end
 
 function M.diff_file(snapshot_id, file_path)
   local relative_path = vim.fn.fnamemodify(file_path, ':.')
+  relative_path = relative_path:gsub('\\', '/')
   local file_at_snapshot = snapshot_git({ 'show', snapshot_id .. ':' .. relative_path })
   local temp_file = write_to_temp_file(file_at_snapshot or '')
   local file_type = vim.fn.fnamemodify(file_path, ':e')
@@ -187,7 +189,8 @@ function M.revert(snapshot_id)
   end
   local deleted_files = {}
   for _, file in ipairs(patch_result.files) do
-    local relative_path = file:match('^' .. vim.fn.getcwd() .. '/?(.*)$')
+    local relative_path = file:match('^' .. vim.pesc(vim.fn.getcwd()) .. '/?(.*)$')
+    relative_path = relative_path:gsub('\\', '/')
     local res, err = snapshot_git({ 'checkout', snapshot_id, '--', relative_path })
     if not res then
       vim.notify(

lua/opencode/types.lua

@@ -389,6 +389,7 @@
 ---@field child_readonly boolean
 ---@field hooks OpencodeHooks
 ---@field quick_chat OpencodeQuickChatConfig
+---@field snapshot_path? string -- Override base path for snapshot storage (default: $XDG_DATA_HOME/opencode). Appends /snapshot/<project_id>/<worktree_hash>
 
 ---@class MessagePartState
 ---@field input TaskToolInput|BashToolInput|FileToolInput|TodoToolInput|GlobToolInput|GrepToolInput|WebFetchToolInput|ListToolInput|QuestionToolInput|ApplyPatchToolInput Input data for the tool

tests/unit/sha1_spec.lua

@@ -0,0 +1,62 @@
+local sha1 = require('opencode.sha1')
+
+describe('sha1', function()
+  it('produces correct hash for empty string', function()
+    assert.equals('da39a3ee5e6b4b0d3255bfef95601890afd80709', sha1(''))
+  end)
+
+  it('produces correct hash for "abc"', function()
+    assert.equals('a9993e364706816aba3e25717850c26c9cd0d89d', sha1('abc'))
+  end)
+
+  it('produces correct hash for "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"', function()
+    assert.equals('84983e441c3bd26ebaae4aa1f95129e5e54670f1', sha1('abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq'))
+  end)
+
+  it('produces correct hash for single character', function()
+    assert.equals('86f7e437faa5a7fce15d1ddcb9eaeaea377667b8', sha1('a'))
+  end)
+
+  it('produces correct hash for "ab"', function()
+    assert.equals('da23614e02469a0d7c7bd1bdab5c9c474b1904dc', sha1('ab'))
+  end)
+
+  it('produces correct hash for numbers', function()
+    assert.equals('01b307acba4f54f55aafc33bb06bbbf6ca803e9a', sha1('1234567890'))
+  end)
+
+  it('produces correct hash for special characters', function()
+    assert.equals('bf24d65c9bb05b9b814a966940bcfa50767c8a8d', sha1('!@#$%^&*()'))
+  end)
+
+  it('produces correct hash for string with spaces', function()
+    assert.equals('2aae6c35c94fcfb415dbe95f408b9ce91ee846ed', sha1('hello world'))
+  end)
+
+  it('produces correct hash for newlines', function()
+    assert.equals('05eed6236c8bda5ecf7af09bae911f9d5f90998b', sha1('line1\nline2'))
+  end)
+
+  it('produces correct hash for null byte', function()
+    assert.equals('dbdd4f85d8a56500aa5c9c8a0d456f96280c92e5', sha1('ab\0c'))
+  end)
+
+  it('produces correct hash for 448-bit message (exactly 56 bytes, boundary condition)', function()
+    local msg = string.rep('a', 56)
+    assert.equals('c2db330f6083854c99d4b5bfb6e8f29f201be699', sha1(msg))
+  end)
+
+  it('produces correct hash for 512-bit message (exactly 64 bytes, one full block)', function()
+    local msg = string.rep('a', 64)
+    assert.equals('0098ba824b5c16427bd7a1122a5a442a25ec644d', sha1(msg))
+  end)
+
+  it('produces correct hash for multi-block message (200 bytes)', function()
+    local msg = string.rep('a', 200)
+    assert.equals('e61cfffe0d9195a525fc6cf06ca2d77119c24a40', sha1(msg))
+  end)
+
+  it('produces correct hash for unicode text', function()
+    assert.equals('24e9f5c07847ff8a2a9fa77456655792f5bc7f9f', sha1('héllo wörld'))
+  end)
+end)