refactor(fs.normalize): ~ expansion

Adds Windows support.

.github/workflows/test.yml

@@ -23,7 +23,7 @@ env:
   NVIM_LOG_FILE: ${{ github.workspace }}/build/.nvimlog
   TSAN_OPTIONS: log_path=${{ github.workspace }}/build/log/tsan
   VALGRIND_LOG: ${{ github.workspace }}/build/log/valgrind-%p.log
-  # TEST_FILE: test/functional/core/startup_spec.lua
+  TEST_FILE: test/functional/lua/fs_spec.lua
   # TEST_FILTER: foo
 
 jobs:

runtime/lua/vim/fs.lua

@@ -489,23 +489,108 @@ end
 ---@param path string
 ---@return string
 local function windows_env_expand(path)
-  -- Variables have a percent sign on both sides: %ThisIsAVariable%
-  -- The variable name can include spaces, punctuation and mixed case:
-  -- %_Another Ex.ample%
-  -- But they aren't case sensitive
-  --
-  -- A variable name may include any of the following characters:
-  -- A-Z, a-z, 0-9, # $ ' ( ) * + , - . ? @ [ ] _  { } ~
-  -- The first character of the name must not be numeric.
-  local pattern = "%%([A-Za-z#$'()*+,%-.?@[%]_{}~ ][A-Za-z0-9#$'()*+,%-.?@[%]_{}~ ]*%)%"
-  return (path:gsub(pattern, vim.uv.os_getenv):gsub('\\', '/'))
+  local res = {}
+  local i = 1
+
+  ---@param var string
+  ---@param end_ number
+  local function add_expand(var, end_)
+    local val = vim.uv.os_getenv(var)
+    if val then
+      table.insert(res, (val:gsub('\\', '/')))
+    else
+      table.insert(res, path:sub(i, end_))
+    end
+  end
+
+  while i <= #path do
+    local ch = path:sub(i, i)
+    if ch == "'" then -- no expansion inside single quotes
+      local end_ = path:find("'", i + 1, true)
+      if end_ then
+        table.insert(res, path:sub(i, end_))
+        i = end_
+      else
+        table.insert(res, ch)
+      end
+    elseif ch == '%' then
+      local end_ = path:find('%', i + 1, true)
+      if end_ then
+        local var = path:sub(i + 1, end_ - 1)
+        add_expand(var, end_)
+        i = end_
+      else
+        table.insert(res, ch)
+      end
+    elseif ch == '$' then
+      local nextch = path:sub(i + 1, i + 1)
+      if nextch == '$' then
+        i = i + 1
+        table.insert(res, ch)
+      elseif nextch == '{' then
+        local end_ = path:find('}', i + 2, true)
+        if end_ then
+          local var = path:sub(i + 2, end_ - 1)
+          add_expand(var, end_)
+          i = end_
+        else
+          table.insert(res, ch)
+        end
+      else
+        local end_ = path:find('[^%w_]', i + 1, false) or #path + 1
+        local var = path:sub(i + 1, end_ - 1)
+        add_expand(var, end_ - 1)
+        i = end_ - 1
+      end
+    else
+      table.insert(res, ch)
+    end
+    i = i + 1
+  end
+
+  return table.concat(res)
 end
 
 ---@param path string
 ---@return string
 local function posix_env_expand(path)
-  local pattern = '%$([A-Za-z_][A-Za-z0-9_]*)'
-  return (path:gsub(pattern, vim.uv.os_getenv))
+  local res = {}
+  local i = 1
+
+  local function add_expand(var, end_)
+    local val = vim.uv.os_getenv(var)
+    if val then
+      table.insert(res, val)
+    else
+      table.insert(res, path:sub(i, end_))
+    end
+  end
+
+  while i <= #path do
+    local ch = path:sub(i, i)
+    if ch == '$' then
+      if path:sub(i + 1, i + 1) == '{' then
+        local end_ = path:find('}', i + 2, true)
+        if end_ then
+          local var = path:sub(i + 2, end_ - 1)
+          add_expand(var, end_)
+          i = end_
+        else
+          table.insert(res, ch)
+        end
+      else
+        local end_ = path:find('[^%w_]', i + 1, false) or #path + 1
+        local var = path:sub(i + 1, end_ - 1)
+        add_expand(var, end_ - 1)
+        i = end_ - 1
+      end
+    else
+      table.insert(res, ch)
+    end
+    i = i + 1
+  end
+
+  return table.concat(res)
 end
 
 --- expand ~/ in a path
@@ -529,7 +614,11 @@ end
 --- @class vim.fs.normalize.Opts
 --- @inlinedoc
 ---
---- Expand environment variables.
+--- Expand environment variables. Substrings in the form of `$VAR` or `${VAR}` are replaced with the
+--- value of the environment variable `VAR`. If the environment variable is not set, the substring
+--- is left unchanged.
+--- On Windows, substrings in the form of `%VAR%` are also replaced unless they are inside single
+--- quotes (eg. `'%VAR%'`).
 --- (default: `true`)
 --- @field expand_env? boolean
 ---

test/functional/lua/fs_spec.lua

@@ -456,26 +456,41 @@ describe('vim.fs', function()
     describe('expands env vars', function()
       before_each(function()
         vim.uv.os_setenv('FOOVAR', 'foo')
-        vim.uv.os_setenv('_BARVAR_42', 'bar')
-        vim.uv.os_setenv('W!NDOW$_CR@ZY', 'windows')
+        vim.uv.os_setenv('{foovar', 'foo1')
+        vim.uv.os_setenv('{foovar}', 'foo\\2')
       end)
 
       after_each(function()
         vim.uv.os_unsetenv('FOOVAR')
-        vim.uv.os_unsetenv('_BARVAR_42')
-        vim.uv.os_unsetenv('W!NDOW$_CR@ZY')
+        vim.uv.os_unsetenv('{foovar')
+        vim.uv.os_unsetenv('{foovar}')
       end)
 
       it('', function()
+        eq('foo', vim.fs.normalize('$FOOVAR'))
+        eq('foo/foo', vim.fs.normalize('$FOOVAR/$FOOVAR'))
+        eq('foo foo', vim.fs.normalize('$FOOVAR $FOOVAR'))
+        eq('foo$', vim.fs.normalize('$FOOVAR$'))
+        eq('foo', vim.fs.normalize('${FOOVAR}'))
+        eq('foo$', vim.fs.normalize('${FOOVAR}$'))
+        eq('foo/foo', vim.fs.normalize('${FOOVAR}/${FOOVAR}'))
+        eq('foo foo', vim.fs.normalize('${FOOVAR} ${FOOVAR}'))
+        eq('${FOO$VAR}', vim.fs.normalize('${FOO$VAR}'))
+        eq('foo/$/bar$', vim.fs.normalize('foo/$/bar$'))
+        eq('foo/${}/bar${}', vim.fs.normalize('foo/${}/bar${}'))
+        eq('$UNSET_ENV_VAR/baz', vim.fs.normalize('$UNSET_ENV_VAR/baz'))
+
         if is_os('win') then
-          eq('foo/bar/baz', vim.fs.normalize('%foobar%/%_BARVAR_42%/baz'))
-          eq('foo/windows/baz', vim.fs.normalize('foo/%W!NDOW$_CR@ZY%/baz'))
-          eq('foo/%UNSET_ENV_VAR%/baz', vim.fs.normalize('foo/%UNSET_ENV_VAR%/baz'))
-        else
-          eq('foo/bar/baz', vim.fs.normalize('$FOOVAR/$_BARVAR_42/baz'))
-          eq('$foovar/bar/baz', vim.fs.normalize('$foovar/$_BARVAR_42/baz'))
-          eq('foo/$1_INVALID_ENV_VAR/baz', vim.fs.normalize('foo/$1_INVALID_ENV_VAR/baz'))
-          eq('foo/$UNSET_ENV_VAR/baz', vim.fs.normalize('foo/$UNSET_ENV_VAR/baz'))
+          eq('foo', vim.fs.normalize('%FOOVAR%'))
+          eq('foo', vim.fs.normalize('%foovar%'))
+          eq('foo1', vim.fs.normalize('%{foovar%'))
+          eq('foo1', vim.fs.normalize('${{foovar}'))
+          eq('foo1}', vim.fs.normalize('${{foovar}}'))
+          eq("'%FOOVAR%'", vim.fs.normalize("'%FOOVAR%'"))
+          eq("'$FOOVAR'", vim.fs.normalize("'$FOOVAR'"))
+          eq("'${FOOVAR}'", vim.fs.normalize("'${FOOVAR}'"))
+          eq('foo/2', vim.fs.normalize('%{foovar}%'))
+          eq('foo/%%/bar%%', vim.fs.normalize('foo/%%/bar%%'))
         end
       end)
     end)