ImportSpy: Proactive Validation for External Python Modules
Posted by atellaluca@reddit | Python | View on Reddit | 12 comments
Have you ever wondered how to ensure that external modules importing your code meet the requirements of your project? With ImportSpy, you can define rules that external modules must follow, ensuring smooth and reliable integration.
What ImportSpy Does:
ImportSpy is an open-source Python library that allows developers to enforce specific rules on external modules that import their code. It ensures these modules meet the required structure, including: • Mandatory Functions: Ensure external modules define critical functions you rely on. • Required Classes: Validate the presence of specific classes, along with their methods and attributes. • Essential Variables: Check for the existence of key variables with their expected values. • Environment Variables: Verify that external modules operate in a properly configured environment, with necessary environment variables set. • Version Control: Enforce compatibility by specifying the required module version.
How It Works:
ImportSpy operates proactively, analyzing any module attempting to import your code. If the module does not comply with the rules you’ve defined, ImportSpy raises a detailed error message highlighting exactly what is missing or non-compliant.
Comparison:
Unlike traditional runtime error detection tools, ImportSpy acts proactively by catching problems before the importing module can even run. Here’s how ImportSpy stands out: 1. Prevention over diagnosis: Instead of debugging unexpected issues after runtime, ImportSpy prevents them from occurring by validating external modules upfront. 2. Custom validation: Developers define their own rules, tailored to the project’s needs, from functions to environment variables. 3. Enhanced integration: Seamlessly works with CI/CD pipelines, ensuring compliance in automated workflows. 4. Actionable feedback: When a module fails validation, ImportSpy provides clear and specific error messages, reducing debugging time.
Other tools might validate only specific elements, like class methods or version numbers, but ImportSpy offers comprehensive, user-defined validation across all critical aspects of a module.
Why It Matters:
Without tools like ImportSpy, identifying errors caused by non-compliant modules can be a time-consuming and frustrating process. ImportSpy prevents these issues at the source by validating external modules during the import process, saving you time and improving the stability of your project.
Who Should Use It:
• Developers building modular or plugin-based architectures: ImportSpy helps ensure all components work seamlessly together.
• Teams prioritizing security and stability: ImportSpy blocks incorrect imports that could compromise your project.
• Anyone leveraging CI/CD pipelines: Ensure critical environment variables are always set as expected.
Key features:
• Proactive validation for external modules, catching issues before runtime.
• Clear and actionable error messages when modules are non-compliant.
• Support for validating environment variables, versioning, functions, and class structures.
• Lightweight and easy to integrate into any Python project.
You can find ImportSpy on GitHub with full documentation and examples to get started:
https://github.com/atellaluca/ImportSpy
nekokattt@reddit
Why would you enforce how other projects using your project are structured?
That feels like a bit of an antipattern, it should be up to that project how it organises itself, rather than it being your cross cutting concern.
Or do I misunderstand something..?
atellaluca@reddit (OP)
Thank you for raising this question, it’s a thoughtful one. ImportSpy isn’t about forcing other projects to follow a specific architectural pattern or structure. Instead, it provides a way for developers to ensure that external modules interacting with their code meet certain requirements for proper integration.
For instance, if you’re developing a library that needs the importing project to define specific classes, functions, or environment variables to function as intended, ImportSpy allows you to validate those expectations. This helps prevent issues like runtime errors or unexpected behavior caused by missing or misconfigured components.
It’s worth emphasizing that ImportSpy doesn’t attempt to reorganize or dictate the overall structure of the importing project. Its purpose is limited to ensuring that the specific parts interacting with your code are compatible and adhere to the rules you define. The level of validation is entirely up to the developer, so it can range from minimal checks to more detailed requirements, depending on the needs of the project.
The goal is to prevent integration issues proactively and make collaboration between codebases more reliable. By catching potential problems early, ImportSpy supports smoother interactions and better project stability. I hope this explanation clarifies things
Schmittfried@reddit
How would that even look like? Your module doesn‘t get to use anything from the one importing yours, it’s the other way around.
You constantly repeat this point, but it would be helpful to see a concrete example. All plugin systems that I know of import the plugins and then obviously interact with functions and classes from them. But they can easily check the presence of them since they’re importing them. I‘ve never seen the reverse and fail to see how this would serve a plugin system and how it should even work.
atellaluca@reddit (OP)
Thank you for your question and for giving me the chance to clarify. ImportSpy is currently being used in a real-world application for a home automation system developed by an Italian company. This system relies on a Python-based framework that serves as the core of every plugin and governs the integration of IoT devices through modular microservices.
The framework leverages ImportSpy to enforce clear and validated rules on plugin structure. Each plugin represents an integration unit for a specific smart device and must adhere to certain requirements to be deemed compliant. For instance, plugins are required to implement specific classes like PluginHandler, include key methods such as initialize or execute, and define mandatory attributes like plugin_name and version. ImportSpy guides developers through this process, raising detailed exceptions whenever a plugin fails to meet the system’s requirements. This ensures that issues can be identified and resolved quickly, allowing plugins to seamlessly integrate into the main framework.
One particularly noteworthy feature of this system is that each plugin is packaged as a separate Docker container, offering a high degree of modularity and scalability. ImportSpy plays a critical role in this pipeline by automatically validating plugins before deployment to ensure they comply with the framework’s rules. This approach enables the company to maintain a stable and reliable ecosystem while simplifying the integration of new smart home devices.
atellaluca@reddit (OP)
Thank you for raising this question, it’s a thoughtful one. ImportSpy isn’t about forcing other projects to follow a specific architectural pattern or structure. Instead, it provides a way for developers to ensure that external modules interacting with their code meet certain requirements for proper integration.
For instance, if you’re developing a library that needs the importing project to define specific classes, functions, or environment variables to function as intended, ImportSpy allows you to validate those expectations. This helps prevent issues like runtime errors or unexpected behavior caused by missing or misconfigured components.
It’s worth emphasizing that ImportSpy doesn’t attempt to reorganize or dictate the overall structure of the importing project. Its purpose is limited to ensuring that the specific parts interacting with your code are compatible and adhere to the rules you define. The level of validation is entirely up to the developer, so it can range from minimal checks to more detailed requirements, depending on the needs of the project.
The goal is to prevent integration issues proactively and make collaboration between codebases more reliable. By catching potential problems early, ImportSpy supports smoother interactions and better project stability. I hope this explanation clarifies things
IAmBJ@reddit
Surely everything you're doing here is already caught by unit tests..
atellaluca@reddit (OP)
Thanks for bringing that up! Unit tests are definitely essential, but they serve a slightly different purpose compared to what ImportSpy does. Unit tests are great for checking the internal logic of a module, making sure that your own code behaves as expected. But ImportSpy looks outward it focuses on how external modules interact with your code.
The idea is to ensure that when someone imports your project, they’re doing so in a way that aligns with your expectations. For example, if you’ve defined that a specific class, method, or variable is required, ImportSpy makes sure those rules are followed before the module is even used. Unit tests don’t typically handle this kind of “integration validation,” since they’re mostly about testing your code’s internal behavior, not its interactions with external modules.
So, ImportSpy doesn’t replace unit tests: it works alongside them to cover a different area. It’s about catching potential integration issues and ensuring your project stays stable and predictable, even when used in larger systems.
Schmittfried@reddit
2.
Unless I‘m building a company-internal foundational library it’s not my place to decide that. And even then enforcing company rules via CI seems cleaner and more obvious than doing it in the dependency itself. CI definitions can use company-wide base templates to ensure that.
Why would I do that? Why do I care about the names/presence of their variables?
atellaluca@reddit (OP)
Hi! First of all, no, I’m not ChatGPT. I use a translator because I don’t speak English fluently, so apologies if the tone comes across as a bit formal or unnatural.
To address your points: you’re absolutely right that CI/CD is a powerful way to enforce rules, and it’s great for catching issues during the pipeline. However, ImportSpy operates at a slightly different level. Its purpose is to validate external modules immediately at the time of import to ensure they meet the specific requirements of your project. This can be crucial in modular systems or plugin-based architectures where missing or incorrect implementations can cause runtime errors or instability.
For example, if you’re building a plugin system where plugins need to implement specific classes, methods, or attributes, ImportSpy ensures these are in place before any logic is executed. It’s not about enforcing arbitrary rules—it’s about guaranteeing compatibility and stability in systems where external code directly interacts with your project.
Regarding the environment validation, I agree it’s a more universally recognizable use case, especially for CI/CD. Still, the class and function validation are particularly valuable in contexts where compliance with a specific API contract is required.
I hope this clears up the purpose of ImportSpy a bit more! Thanks for your thoughtful feedback.
atellaluca@reddit (OP)
ImportSpy does not replace unit tests but complements them, acting as a structural safeguard to prevent non-compliant modules from interfering with your project
I_am_bigmacd@reddit
Thanks for this! I will definitely check it out. At first glance it seems to address a few areas that are not covered by our other security tooling like safety, vulnapi, twyn, and acSecurity.
atellaluca@reddit (OP)
Thank you. I’m glad ImportSpy caught your attention. Its focus is on proactively validating external modules to ensure compliance with predefined rules, something that complements security tools by targeting integration reliability and structural validation. If you get a chance to try it out, I’d love to hear your feedback on how ImportSpy fits into your workflow and whether it addresses the gaps you mentioned