# fundi-scopegen

Type-safe scope declaration generator for fundi dependency injection

fundi-codegen generates TypedDict classes that describe the expected scope structure for fundi-based functions.
This allows you to call inject(scope, scan(...), stack) with full type checking, autocomplete, and IDE support — no plugins or runtime introspection needed.

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HOW IT WORKS

fundi-scopegen analyzes a function (and its dependency tree) via scan(...), extracts all from_(...) and outputs:

• a full list of all keys required in the scope
• expected types (supporting FromType, Literal, Optional, Union, Annotated, Parameter, etc.)
• import statements for required symbols
• a TypedDict class that serves as a contract for what the scope must contain

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How it works:

1. Recursively walks the dependency tree using scan(...)
2. Detects all from_(...)-based dependencies
3. Builds a TypedDict based on flattened parameter annotations
4. Outputs a ready-to-use Python type declaration

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USAGE EXAMPLES

Generate a scope for a function

fundi-scopegen play.application

Output:

from typing import Any, TypedDict, NotRequired
from fundi import FromType
from fundi.types import Parameter

class ApplicationScope(TypedDict):
    parameter: NotRequired[FromType[None | Parameter]]
    app_name: NotRequired[str | None]
    some: NotRequired[str]
    username: Any

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With terminal color (for CLI readability)

fundi-scopegen play.application --colored

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Without imports

fundi-scopegen play.application --no-imports

Output:

class ApplicationScope(TypedDict):
    parameter: NotRequired[FromType[None | Parameter]]
    app_name: NotRequired[str | None]
    some: NotRequired[str]
    username: Any

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Using it in code

from contextlib import ExitStack

from fundi import inject, scan

from play import application
from scopes import ApplicationScope

scope: ApplicationScope = {
    "username": "kuyugama",
    "some": "waffel",
}

with ExitStack() as stack:
    result = inject(scope, scan(application), stack)

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Benefits

• Full IDE autocomplete
• Type-checking with mypy or pyright
• Lightweight: no runtime cost or decorators
• Easy to regenerate on dependency changes

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🐾 Stop guessing your scope shape. Generate it once, and type it forever 😼