py/repl: Skip private variables when printing tab completion options.

Any '_' variables/functions in frozen modules are currently printed, when
they shouldn't be.  That's due to underscore names possibly existing
between the start and end qstrs which are used to print the auto-complete
matches.  The underscore names should be skipped when iterating between the
two boundary qstrs.

The underscore attributes are removed from the extra coverage exp file
because tab completing "import <tab>" no longer lists modules beginning
with an underscore.

Signed-off-by: Andrew Leech <andrew.leech@planetinnovation.com.au>

py/repl.c

@@ -218,6 +218,10 @@ static void print_completions(const mp_print_t *print,
     for (qstr q = q_first; q <= q_last; ++q) {
         size_t d_len;
         const char *d_str = (const char *)qstr_data(q, &d_len);
+        // filter out words that begin with underscore unless there's already a partial match
+        if (s_len == 0 && d_str[0] == '_') {
+            continue;
+        }
         if (s_len <= d_len && strncmp(s_start, d_str, s_len) == 0) {
             if (test_qstr(obj, q)) {
                 int gap = (line_len + WORD_SLOT_LEN - 1) / WORD_SLOT_LEN * WORD_SLOT_LEN - line_len;

pyproject.toml

@@ -29,6 +29,7 @@ target-version = "py37"
 [tool.ruff.lint]
 exclude = [  # Ruff finds Python SyntaxError in these files
   "tests/cmdline/repl_autocomplete.py",
+  "tests/cmdline/repl_autocomplete_underscore.py",
   "tests/cmdline/repl_autoindent.py",
   "tests/cmdline/repl_basic.py",
   "tests/cmdline/repl_cont.py",

tests/cmdline/repl_autocomplete_underscore.py

@@ -0,0 +1,33 @@
+# Test REPL autocompletion filtering of underscore attributes
+
+# Start paste mode
+{\x05}
+class TestClass:
+    def __init__(self):
+        self.public_attr = 1
+        self._private_attr = 2
+        self.__very_private = 3
+    
+    def public_method(self):
+        pass
+    
+    def _private_method(self):
+        pass
+    
+    @property
+    def public_property(self):
+        return 42
+    
+    @property  
+    def _private_property(self):
+        return 99
+
+{\x04}
+# Paste executed
+
+# Create an instance
+obj = TestClass()
+
+# Test tab completion on the instance
+# The tab character after `obj.` and 'a' below triggers the completions
+obj.{\x09}{\x09}a{\x09}

tests/cmdline/repl_autocomplete_underscore.py.exp

@@ -0,0 +1,41 @@
+MicroPython \.\+ version
+Use Ctrl-D to exit, Ctrl-E for paste mode
+>>> # Test REPL autocompletion filtering of underscore attributes
+>>> 
+>>> # Start paste mode
+>>> 
+paste mode; Ctrl-C to cancel, Ctrl-D to finish
+=== 
+=== class TestClass:
+===     def __init__(self):
+===         self.public_attr = 1
+===         self._private_attr = 2
+===         self.__very_private = 3
+===     
+===     def public_method(self):
+===         pass
+===     
+===     def _private_method(self):
+===         pass
+===     
+===     @property
+===     def public_property(self):
+===         return 42
+===     
+===     @property  
+===     def _private_property(self):
+===         return 99
+=== 
+=== 
+>>> # Paste executed
+>>> 
+>>> # Create an instance
+>>> obj = TestClass()
+>>> 
+>>> # Test tab completion on the instance
+>>> # The tab character after `obj.` and 'a' below triggers the completions
+>>> obj.public_
+public_attr     public_method   public_property
+>>> obj.public_attr
+1
+>>> 

tests/ports/unix/extra_coverage.py.exp

@@ -51,16 +51,16 @@ RuntimeError:
 ame__
 port 
 
-builtins        micropython     _asyncio        _thread
+builtins        micropython     array           binascii
-array           binascii        btree           cexample
+btree           cexample        cmath           collections
-cmath           collections     cppexample      cryptolib
+cppexample      cryptolib       deflate         errno
-deflate         errno           example_package
+example_package                 ffi             framebuf
-ffi             framebuf        gc              hashlib
+gc              hashlib         heapq           io
-heapq           io              json            machine
+json            machine         marshal         math
-marshal         math            os              platform
+os              platform        random          re
-random          re              select          socket
+select          socket          struct          sys
-struct          sys             termios         time
+termios         time            tls             uctypes
-tls             uctypes         vfs             websocket
+vfs             websocket
 me
 
 micropython     machine         marshal         math