Address PR comments.

2026-06-16 21:04:09 +08:00 · 2026-06-11 10:35:34 -07:00
parent c0ea099bd8
commit 4b0aeb76a5
3 changed files with 168 additions and 73 deletions
@@ -269,6 +269,9 @@ class DeclarativeWorkflowState:
    - Conversation: Conversation history
    """

+    # Sentinel marking "no prior value" for temporary-key bookkeeping.
+    _MISSING: Any = object()
+
    def __init__(self, state: State, env_config: DeclarativeEnvConfig | None = None):
        """Initialize with a State instance.

@@ -492,6 +495,15 @@ class DeclarativeWorkflowState:
        else:
            raise ValueError(f"Cannot append to non-list at path '{path}'")

+    def _clear_local_path(self, name: str) -> None:
+        """Remove ``name`` from the ``Local`` namespace, if present."""
+        state_data = self.get_state_data()
+        local = cast(dict[str, Any], state_data.get("Local"))
+        if local is None or name not in local:
+            return
+        local.pop(name, None)
+        self.set_state_data(state_data)
+
    def eval(self, expression: str) -> Any:
        """Evaluate a PowerFx expression with the current state.

@@ -532,53 +544,64 @@ class DeclarativeWorkflowState:
            return result

        # Pre-process nested custom functions (e.g., Upper(MessageText(...)))
-        # Replace them with their evaluated results before sending to PowerFx
-        formula = self._preprocess_custom_functions(formula)
+        # and run PowerFx. The finally below restores any temporary state
+        # written during preprocessing, regardless of where execution exits.
+        temp_writes: list[tuple[str, Any]] = []

-        if Engine is None:
-            raise RuntimeError(
-                f"PowerFx is not available (dotnet runtime not installed). "
-                f"Expression '={formula[:80]}' cannot be evaluated. "
-                f"Install dotnet and the powerfx package for full PowerFx support."
-            )
-
-        symbols = self._to_powerfx_symbols()
-        # Use setlocale(category) query form so we can restore the exact prior value.
-        # getlocale() returns a normalized tuple and is not always a lossless
-        # round-trip for setlocale across platforms/locales.
-        original_numeric_locale = locale.setlocale(locale.LC_NUMERIC)
        try:
-            for locale_candidate in _POWERFX_NUMERIC_LOCALE_CANDIDATES:
-                try:
-                    locale.setlocale(locale.LC_NUMERIC, locale_candidate)
-                    break
-                except locale.Error:
-                    continue
+            formula = self._preprocess_custom_functions(formula, temp_writes)

-            engine = Engine()
-            try:
-                from System.Globalization import (  # pyright: ignore[reportMissingImports]
-                    CultureInfo,  # pyright: ignore[reportUnknownVariableType]
+            if Engine is None:
+                raise RuntimeError(
+                    f"PowerFx is not available (dotnet runtime not installed). "
+                    f"Expression '={formula[:80]}' cannot be evaluated. "
+                    f"Install dotnet and the powerfx package for full PowerFx support."
                )
-            except ImportError:
-                return engine.eval(formula, symbols=symbols, locale=_POWERFX_EVAL_LOCALE)

-            original_culture = cast(Any, CultureInfo.CurrentCulture)  # pyright: ignore[reportUnknownMemberType]
+            symbols = self._to_powerfx_symbols()
+            # Use setlocale(category) query form so we can restore the exact prior value.
+            # getlocale() returns a normalized tuple and is not always a lossless
+            # round-trip for setlocale across platforms/locales.
+            original_numeric_locale = locale.setlocale(locale.LC_NUMERIC)
            try:
-                CultureInfo.CurrentCulture = CultureInfo(_POWERFX_EVAL_LOCALE)  # pyright: ignore[reportUnknownMemberType, reportUnknownVariableType]
-                return engine.eval(formula, symbols=symbols, locale=_POWERFX_EVAL_LOCALE)
+                for locale_candidate in _POWERFX_NUMERIC_LOCALE_CANDIDATES:
+                    try:
+                        locale.setlocale(locale.LC_NUMERIC, locale_candidate)
+                        break
+                    except locale.Error:
+                        continue
+
+                engine = Engine()
+                try:
+                    from System.Globalization import (  # pyright: ignore[reportMissingImports]
+                        CultureInfo,  # pyright: ignore[reportUnknownVariableType]
+                    )
+                except ImportError:
+                    return engine.eval(formula, symbols=symbols, locale=_POWERFX_EVAL_LOCALE)
+
+                original_culture = cast(Any, CultureInfo.CurrentCulture)  # pyright: ignore[reportUnknownMemberType]
+                try:
+                    CultureInfo.CurrentCulture = CultureInfo(_POWERFX_EVAL_LOCALE)  # pyright: ignore[reportUnknownMemberType, reportUnknownVariableType]
+                    return engine.eval(formula, symbols=symbols, locale=_POWERFX_EVAL_LOCALE)
+                finally:
+                    CultureInfo.CurrentCulture = original_culture  # pyright: ignore[reportUnknownMemberType]
+            except ValueError as e:
+                error_msg = str(e)
+                # Handle undefined variable errors gracefully by returning None
+                # This matches the behavior of the legacy fallback parser
+                if "isn't recognized" in error_msg or "Name isn't valid" in error_msg:
+                    logger.debug(f"PowerFx: undefined variable in expression '{formula}', returning None")
+                    return None
+                raise
            finally:
-                CultureInfo.CurrentCulture = original_culture  # pyright: ignore[reportUnknownMemberType]
-        except ValueError as e:
-            error_msg = str(e)
-            # Handle undefined variable errors gracefully by returning None
-            # This matches the behavior of the legacy fallback parser
-            if "isn't recognized" in error_msg or "Name isn't valid" in error_msg:
-                logger.debug(f"PowerFx: undefined variable in expression '{formula}', returning None")
-                return None
-            raise
+                locale.setlocale(locale.LC_NUMERIC, original_numeric_locale)
        finally:
-            locale.setlocale(locale.LC_NUMERIC, original_numeric_locale)
+            # Restore each temporary key to its prior value (or remove it).
+            for path, previous in reversed(temp_writes):
+                if previous is self._MISSING:
+                    self._clear_local_path(path.removeprefix("Local."))
+                else:
+                    self.set(path, previous)

    def _eval_custom_function(self, formula: str) -> Any | None:
        """Handle custom functions not supported by the Python PowerFx library.
@@ -637,7 +660,7 @@ class DeclarativeWorkflowState:

        return None

-    def _preprocess_custom_functions(self, formula: str) -> str:
+    def _preprocess_custom_functions(self, formula: str, temp_writes: list[tuple[str, Any]]) -> str:
        """Pre-process custom functions nested inside other PowerFx functions.

        Custom functions like MessageText() are not supported by the PowerFx engine.
@@ -652,9 +675,14 @@ class DeclarativeWorkflowState:

        Args:
            formula: The PowerFx formula to pre-process
+            temp_writes: Caller-owned list. Each write to a temporary key
+                appends a ``(path, previous_value)`` entry where
+                ``previous_value`` is the value at ``path`` before the write
+                or :attr:`_MISSING` if none. The caller must restore every
+                entry, including when this method raises mid-write.

        Returns:
-            The formula with custom function calls replaced by their evaluated results
+            The rewritten formula.
        """
        import re

@@ -663,7 +691,6 @@ class DeclarativeWorkflowState:
        # We use 500 to leave room for the rest of the expression around the replaced value.
        MAX_INLINE_LENGTH = 500

-        # Counter for generating unique temp variable names
        temp_var_counter = 0

        # Custom functions that need pre-processing: (regex pattern, handler)
@@ -719,11 +746,14 @@ class DeclarativeWorkflowState:
                # Replace in formula
                if isinstance(replacement, str):
                    if len(replacement) > MAX_INLINE_LENGTH:
-                        # Store long strings in a temp variable to avoid PowerFx expression limit
-                        temp_var_name = f"TempMessageText{temp_var_counter}"
+                        # Store long results in an underscore-prefixed temp key;
+                        # record the prior value so eval() can restore it.
+                        temp_var_name = f"_TempMessageText{temp_var_counter}"
                        temp_var_counter += 1
-                        self.set(f"Local.{temp_var_name}", replacement)
-                        replacement_str = f"Local.{temp_var_name}"
+                        temp_var_path = f"Local.{temp_var_name}"
+                        temp_writes.append((temp_var_path, self.get(temp_var_path, default=self._MISSING)))
+                        self.set(temp_var_path, replacement)
+                        replacement_str = temp_var_path
                        logger.debug(
                            f"Stored long MessageText result ({len(replacement)} chars) "
                            f"in temp variable {temp_var_name}"
@@ -875,14 +905,13 @@ class DeclarativeWorkflowState:
        return value

    def interpolate_string(self, text: str) -> str:
-        """Interpolate {Variable.Path} references in a string.
+        """Interpolate ``{Variable.Path}`` references in a string.

-        Matched path segments must be valid declarative identifiers
-        (``[A-Za-z][A-Za-z0-9_]*``); other braced tokens are left as-is.
-
-        This handles template-style variable substitution like:
-        - "Created ticket #{Local.TicketParameters.TicketId}"
-        - "Routing to {Local.RoutingParameters.TeamName}"
+        Captures brace-delimited tokens whose root segment is an identifier
+        (``[A-Za-z][A-Za-z0-9_]*``) followed by zero or more ``.`` separated
+        dict-key segments. Resolution is delegated to :meth:`get`; unresolved
+        tokens are replaced with the empty string. Tokens that do not look
+        like state paths (e.g. ``{foo-bar}``, ``{Ctrl+C}``) are left literal.

        Args:
            text: Text that may contain {Variable.Path} references
@@ -897,10 +926,11 @@ class DeclarativeWorkflowState:
            value = self.get(var_path)
            return str(value) if value is not None else ""

-        # Match {Variable.Path} patterns where each segment is a declarative identifier.
-        pattern = r"\{([A-Za-z][A-Za-z0-9_]*(?:\.[A-Za-z][A-Za-z0-9_]*)*)\}"
+        # Root segment must be an identifier; follow-on segments accept any
+        # non-empty dict-key (e.g. ``_id``, ``1``, UUIDs). ``get()`` enforces
+        # per-segment safety on attribute traversal.
+        pattern = r"\{([A-Za-z][A-Za-z0-9_]*(?:\.[^{}\s.]+)*)\}"

-        # Replace all matches
        result = text
        for match in re.finditer(pattern, text):
            replacement = replace_var(match)