redo of tuple starred assignments; on mismatch exception, no variables are assigned

Author: craigbarratt

custom_components/pyscript/eval.py

@@ -607,35 +607,37 @@ async def recurse_assign(self, lhs, val):
         """Recursive assignment."""
         if isinstance(lhs, ast.Tuple):
             try:
-                val_iter = val.__iter__()
-            except AttributeError:
+                vals = [*(val.__iter__())]
+            except Exception:  # pylint: disable=broad-except
                 raise TypeError("cannot unpack non-iterable object")
-            sentinel = object()
-            for lhs_idx, lhs_elt in enumerate(lhs.elts):
-                val_elt = next(val_iter, sentinel)
-                if val_elt is sentinel:
-                    raise ValueError(
-                        f"too few values to unpack (expected {len(lhs.elts)})"
-                    )
+            got_star = 0
+            for lhs_elt in lhs.elts:
                 if isinstance(lhs_elt, ast.Starred):
-                    star_lhs = [val_elt, *val_iter]
-                    star_len = len(star_lhs) - (len(lhs.elts) - lhs_idx - 1)
-                    if star_len < 0:
-                        raise ValueError(
-                            f"too few values to unpack (expected at least {len(lhs.elts) - 1})"
-                        )
-                    star_name = lhs_elt.value.id
-                    for lhs_idx2, lhs_elt in enumerate(lhs.elts[lhs_idx + 1 :]):
-                        await self.recurse_assign(lhs_elt, star_lhs[star_len + lhs_idx2])
-                    await self.recurse_assign(
-                        ast.Name(id=star_name, ctx=ast.Store()), star_lhs[0:star_len]
-                    )
-                    return
-                await self.recurse_assign(lhs_elt, val_elt)
-            if next(val_iter, sentinel) is not sentinel:
+                    got_star = 1
+                    break
+            if len(lhs.elts) > len(vals) + got_star:
+                if got_star:
+                    err_msg = f"at least {len(lhs.elts) - got_star}"
+                else:
+                    err_msg = f"{len(lhs.elts)}"
+                raise ValueError(f"too few values to unpack (expected {err_msg})")
+            if len(lhs.elts) < len(vals) and got_star == 0:
                 raise ValueError(
                     f"too many values to unpack (expected {len(lhs.elts)})"
                 )
+            val_idx = 0
+            for lhs_elt in lhs.elts:
+                if isinstance(lhs_elt, ast.Starred):
+                    star_len = len(vals) - len(lhs.elts) + 1
+                    star_name = lhs_elt.value.id
+                    await self.recurse_assign(
+                        ast.Name(id=star_name, ctx=ast.Store()),
+                        vals[val_idx : val_idx + star_len],
+                    )
+                    val_idx += star_len
+                else:
+                    await self.recurse_assign(lhs_elt, vals[val_idx])
+                    val_idx += 1
         elif isinstance(lhs, ast.Subscript):
             var = await self.aeval(lhs.value)
             if isinstance(lhs.slice, ast.Index):

tests/custom_components/pyscript/test_func.py

@@ -33,8 +33,7 @@ async def setup_script(hass, notify_q, now, source):
     )
 
     with patch(
-        "homeassistant.loader.async_get_integration",
-        return_value=integration,
+        "homeassistant.loader.async_get_integration", return_value=integration,
     ), patch(
         "config.custom_components.pyscript.os.path.isdir", return_value=True
     ), patch(

tests/custom_components/pyscript/test_init.py

@@ -34,8 +34,7 @@ async def setup_script(hass, notify_q, now, source):
     )
 
     with patch(
-        "homeassistant.loader.async_get_integration",
-        return_value=integration,
+        "homeassistant.loader.async_get_integration", return_value=integration,
     ), patch(
         "config.custom_components.pyscript.os.path.isdir", return_value=True
     ), patch(
@@ -87,8 +86,7 @@ async def test_setup_fails_on_no_dir(hass, caplog):
     )
 
     with patch(
-        "homeassistant.loader.async_get_integration",
-        return_value=integration,
+        "homeassistant.loader.async_get_integration", return_value=integration,
     ), patch("config.custom_components.pyscript.os.path.isdir", return_value=False):
         res = await async_setup_component(hass, "pyscript", {DOMAIN: {}})
 
@@ -434,8 +432,7 @@ def func5(var_name=None, value=None):
         )
 
         with patch(
-            "homeassistant.loader.async_get_integration",
-            return_value=integration,
+            "homeassistant.loader.async_get_integration", return_value=integration,
         ), patch(
             "config.custom_components.pyscript.os.path.isdir", return_value=True
         ), patch(

tests/custom_components/pyscript/test_unique.py

@@ -32,8 +32,7 @@ async def setup_script(hass, notify_q, now, source):
     )
 
     with patch(
-        "homeassistant.loader.async_get_integration",
-        return_value=integration,
+        "homeassistant.loader.async_get_integration", return_value=integration,
     ), patch(
         "config.custom_components.pyscript.os.path.isdir", return_value=True
     ), patch(

tests/custom_components/pyscript/test_unit_eval.py

@@ -658,11 +658,7 @@ def get(self):
 async def run_one_test(test_data):
     """Run one interpreter test."""
     source, expect = test_data
-    global_ctx = GlobalContext(
-        "test",
-        None,
-        global_sym_table={},
-    )
+    global_ctx = GlobalContext("test", None, global_sym_table={})
     ast = AstEval("test", global_ctx=global_ctx)
     ast.parse(source)
     if ast.get_exception() is not None:
@@ -692,27 +688,27 @@ def test_eval(hass):
     ["xx", "Exception in test line 1 column 0: name 'xx' is not defined"],
     [
         "(x, y) = (1, 2, 4)",
-        "Exception in test line 1 column 4: too many values to unpack (expected 2)",
+        "Exception in test line 1 column 16: too many values to unpack (expected 2)",
     ],
     [
         "(x, y) = iter([1, 2, 4])",
-        "Exception in test line 1 column 4: too many values to unpack (expected 2)",
+        "Exception in test line 1 column 21: too many values to unpack (expected 2)",
     ],
     [
         "(x, y, z) = (1, 2)",
-        "Exception in test line 1 column 4: too few values to unpack (expected 3)",
+        "Exception in test line 1 column 16: too few values to unpack (expected 3)",
     ],
     [
         "(x, y, z) = iter([1, 2])",
-        "Exception in test line 1 column 4: too few values to unpack (expected 3)",
+        "Exception in test line 1 column 21: too few values to unpack (expected 3)",
     ],
     [
         "(x, y) = 1",
         "Exception in test line 1 column 9: cannot unpack non-iterable object",
     ],
     [
         "a, *y, w, z = range(2)",
-        "Exception in test line 1 column 0: too few values to unpack (expected at least 3)",
+        "Exception in test line 1 column 20: too few values to unpack (expected at least 3)",
     ],
     [
         "assert 1 == 0, 'this is an error'",