Allow quick open with pre-populated query and non-directories (#76)

Make the quick cd behavior trigger even if the user was starting to type a token and even if the path is not a directory. Before, it would only prepend ./ if the command line was empty and the selected path is a directory.

Now, if the user was in the middle of inputting the first token and only one path is selected, then prepend ./ to the selected path so that
 - if the path is an executable, the user can hit Enter one more time to immediately execute it
 - if the path is a directory, the user can hit Enter one more time to immediately cd into it

Author: kidonng

README.md

@@ -20,7 +20,7 @@ Use `fzf.fish` to interactively find and insert into the command line:
 - **Key binding and mnemonic:** <kbd>Ctrl</kbd>+<kbd>F</kbd> (`F` for file)
 - **Preview window:** file with syntax highlighting, directory contents, or file type
 - **Remarks**
-  - appends `./` to the selection if the selection is a single directory, allowing for quick cd into that directory (see [cd docs][])
+  - prepends `./` to the selection if only one selection is made and it becomes the only token on the command line, making it easy to execute if an executable, or cd into if a directory (see [cd docs][])
   - if the current token is a directory with a trailing slash (e.g. `functions/<CURSOR>`), then search will be scoped to that directory
   - ignores files that are also ignored by git
   - <kbd>Tab</kbd> to multi-select

functions/__fzf_search_current_dir.fish

@@ -21,11 +21,17 @@ function __fzf_search_current_dir --description "Search the current directory. R
 
 
     if test $status -eq 0
-        # If this function was triggered with an empty command line and the only thing selected is a directory, then
-        # prepend ./ to the dir path. Because fish will attempt to cd implicitly if a directory name starting with a dot
-        # is provided, this allows the user to hit Enter one more time to quickly cd into the selected directory.
-        if test (count (commandline --tokenize)) = 0 && test (count $file_paths_selected) = 1 && test -d $file_paths_selected
-            set file_paths_selected ./$file_paths_selected
+        # If the user was in the middle of inputting the first token and only one path is selected,
+        # then prepend ./ to the selected path so that
+        # - if the path is an executable, the user can hit Enter one more time to immediately execute it
+        # - if the path is a directory, the user can hit Enter one more time to immediately cd into it (fish will
+        #   attempt to cd implicitly if a directory name starts with a dot)
+        if test (count $file_paths_selected) = 1
+            set commandline_tokens (commandline --tokenize)
+            set current_token (commandline --current-token)
+            if test "$commandline_tokens" = "$current_token"
+                set file_paths_selected ./$file_paths_selected
+            end
         end
 
         commandline --current-token --replace (string escape $file_paths_selected | string join ' ')