forgeenv/primitives/repair_primitives.py

"""Repair primitives — direct inverses of the 8 breakage primitives.

Used during warm-start data generation: for every (script, breakage)
pair we know the canonical repair, so we can write SFT pairs.

These are also useful for unit-testing the breakage primitives:
apply(breakage) then apply(repair) should be (close to) the identity.
"""
from __future__ import annotations

import re
from abc import ABC, abstractmethod
from dataclasses import dataclass, field


@dataclass
class RepairPrimitive(ABC):
    category: str = field(default="generic", init=False)
    name: str = field(default="RepairPrimitive", init=False)
    description: str = field(default="", init=False)

    @abstractmethod
    def apply(self, script: str) -> str:
        """Transform `script` to undo the corresponding breakage."""

    def to_spec(self) -> dict:
        return {
            "primitive_type": self.__class__.__name__,
            "category": self.category,
            "params": self._get_params(),
        }

    @abstractmethod
    def _get_params(self) -> dict:
        """Return JSON-serializable constructor parameters."""


@dataclass
class RestoreApiCall(RepairPrimitive):
    new_name: str = ""
    old_name: str = ""

    def __post_init__(self) -> None:
        self.category = "api_drift"
        self.name = "RestoreApiCall"
        self.description = f"Rename {self.new_name} -> {self.old_name}"

    def apply(self, script: str) -> str:
        if not self.new_name:
            return script
        pattern = re.compile(rf"(?<!\w){re.escape(self.new_name)}(?!\w)")
        return pattern.sub(self.old_name, script)

    def _get_params(self) -> dict:
        return {"new_name": self.new_name, "old_name": self.old_name}


@dataclass
class RestoreImport(RepairPrimitive):
    new_module: str = ""
    old_module: str = ""

    def __post_init__(self) -> None:
        self.category = "import_drift"
        self.name = "RestoreImport"
        self.description = f"Restore import {self.new_module} -> {self.old_module}"

    def apply(self, script: str) -> str:
        return script.replace(self.new_module, self.old_module)

    def _get_params(self) -> dict:
        return {"new_module": self.new_module, "old_module": self.old_module}


@dataclass
class RestoreArgument(RepairPrimitive):
    """Re-add a removed argument to a function call."""

    function_name: str = ""
    arg_name: str = ""
    arg_value: str = ""

    def __post_init__(self) -> None:
        self.category = "api_drift"
        self.name = "RestoreArgument"
        self.description = (
            f"Add {self.arg_name}={self.arg_value} to {self.function_name}()"
        )

    def apply(self, script: str) -> str:
        if not self.function_name:
            return script
        # Insert the kwarg right after the function-name's opening paren.
        pattern = rf"({re.escape(self.function_name)}\s*\()(\s*)"
        replacement = rf"\g<1>{self.arg_name}={self.arg_value}, \g<2>"
        return re.sub(pattern, replacement, script, count=1)

    def _get_params(self) -> dict:
        return {
            "function_name": self.function_name,
            "arg_name": self.arg_name,
            "arg_value": self.arg_value,
        }


@dataclass
class RestoreConfigField(RepairPrimitive):
    field_name: str = ""
    old_value: str = ""

    def __post_init__(self) -> None:
        self.category = "config_drift"
        self.name = "RestoreConfigField"
        self.description = f"Restore {self.field_name}={self.old_value}"

    def apply(self, script: str) -> str:
        if not self.field_name:
            return script
        pattern = rf"({re.escape(self.field_name)}\s*=\s*)([^,)\n]+)"
        return re.sub(pattern, rf"\g<1>{self.old_value}", script)

    def _get_params(self) -> dict:
        return {"field_name": self.field_name, "old_value": self.old_value}


@dataclass
class RestoreColumn(RepairPrimitive):
    new_column: str = ""
    old_column: str = ""

    def __post_init__(self) -> None:
        self.category = "dataset_drift"
        self.name = "RestoreColumn"
        self.description = f"Rename column {self.new_column} -> {self.old_column}"

    def apply(self, script: str) -> str:
        return script.replace(
            f'"{self.new_column}"', f'"{self.old_column}"'
        ).replace(
            f"'{self.new_column}'", f"'{self.old_column}'"
        )

    def _get_params(self) -> dict:
        return {"new_column": self.new_column, "old_column": self.old_column}


@dataclass
class RestoreTokenizerKwarg(RepairPrimitive):
    new_kwarg: str = ""
    new_value: str = ""
    old_kwarg: str = ""
    old_value: str = ""

    def __post_init__(self) -> None:
        self.category = "tokenizer_drift"
        self.name = "RestoreTokenizerKwarg"
        self.description = (
            f"Restore tokenizer {self.new_kwarg}={self.new_value} -> "
            f"{self.old_kwarg}={self.old_value}"
        )

    def apply(self, script: str) -> str:
        if not self.new_kwarg:
            return script
        pattern = rf"{re.escape(self.new_kwarg)}\s*=\s*{re.escape(self.new_value)}"
        replacement = f"{self.old_kwarg}={self.old_value}"
        return re.sub(pattern, replacement, script)

    def _get_params(self) -> dict:
        return {
            "new_kwarg": self.new_kwarg,
            "new_value": self.new_value,
            "old_kwarg": self.old_kwarg,
            "old_value": self.old_value,
        }


@dataclass
class RestoreMethod(RepairPrimitive):
    method_name: str = ""

    def __post_init__(self) -> None:
        self.category = "api_drift"
        self.name = "RestoreMethod"
        self.description = f"Un-deprecate .{self.method_name}()"

    def apply(self, script: str) -> str:
        if not self.method_name:
            return script
        return script.replace(
            f".{self.method_name}_DEPRECATED(", f".{self.method_name}("
        )

    def _get_params(self) -> dict:
        return {"method_name": self.method_name}


@dataclass
class RestoreReturnAccess(RepairPrimitive):
    new_access: str = ""
    old_access: str = ""

    def __post_init__(self) -> None:
        self.category = "api_drift"
        self.name = "RestoreReturnAccess"
        self.description = f"Restore return-access {self.new_access} -> {self.old_access}"

    def apply(self, script: str) -> str:
        if not self.new_access:
            return script
        return script.replace(self.new_access, self.old_access)

    def _get_params(self) -> dict:
        return {"new_access": self.new_access, "old_access": self.old_access}


REPAIR_REGISTRY: dict[str, type[RepairPrimitive]] = {
    "RestoreApiCall": RestoreApiCall,
    "RestoreImport": RestoreImport,
    "RestoreArgument": RestoreArgument,
    "RestoreConfigField": RestoreConfigField,
    "RestoreColumn": RestoreColumn,
    "RestoreTokenizerKwarg": RestoreTokenizerKwarg,
    "RestoreMethod": RestoreMethod,
    "RestoreReturnAccess": RestoreReturnAccess,
}


# Map a breakage primitive's class name to the repair-primitive class that
# inverts it. Used by the warm-start pair generator and by the demo / repair
# library curator.
BREAKAGE_TO_REPAIR: dict[str, str] = {
    "RenameApiCall": "RestoreApiCall",
    "DeprecateImport": "RestoreImport",
    "ChangeArgumentSignature": "RestoreArgument",
    "ModifyConfigField": "RestoreConfigField",
    "RestructureDatasetSchema": "RestoreColumn",
    "ChangeTokenizerBehavior": "RestoreTokenizerKwarg",
    "RemoveDeprecatedMethod": "RestoreMethod",
    "ChangeReturnType": "RestoreReturnAccess",
}