Refact to support nested structs

[alexgarzao]

This PR refactors and enhances the validgen codebase by introducing modular components for parsing, analyzing, and generating validation code for Go structs. Basically now we have a pipeline composed of the parser, the analyzer and the code generator. It includes significant restructuring, new functionality for validation code generation, and updates to tests and integration logic.

Refactoring and Modularization:

• The validgen package has been split into three new internal packages: parser, analyzer, and codegenerator, each handling a distinct aspect of the validation process. Files and functions have been renamed and moved accordingly. ([[1]](https://github.com/opencodeco/validgen/pull/37/files#diff-2e516d6180c079f7445cc566a07cb613237db1dcae80a15f9427e31b106f11feL1-R1), [[2]](https://github.com/opencodeco/validgen/pull/37/files#diff-4a2689cbce28727a3ba2f050fcd06330829b7631d36bfb5d0bb3f2e28d359189L1-R1), [[3]](https://github.com/opencodeco/validgen/pull/37/files#diff-a805abe62add9666cbcd835268eed6be4343bcd6647ec608325825137aadc6a6L1-R7), [[4]](https://github.com/opencodeco/validgen/pull/37/files#diff-739ba07c8d00c05d17bdfe8fddf15e12650806d3112ed68324de3986678a171fL1-R13))

New Features:

• Added a parser module to extract and parse Go structs from .go files, including their tags and fields. ([[1]](https://github.com/opencodeco/validgen/pull/37/files#diff-d1655fd776ca5fcf2821d7a478d18e80e68fc75d43a8aabeb5fbb07197c4f3ccR1-R134), [[2]](https://github.com/opencodeco/validgen/pull/37/files#diff-dc19824db1734891e5fdc65f58908f0620c7611b24053fd1dd9c8cac69657d07R1-R43))
• Introduced an analyzer module to process struct tags and extract validation rules into a structured format. ([internal/analyzer/analyzer.goR1-R40](https://github.com/opencodeco/validgen/pull/37/files#diff-b126d19c61b7249f14710696139d71e966aa643a9a363ad19e639e14cef6e41eR1-R40))
• Implemented a codegenerator module to generate validation code based on analyzed structs, including template-based code generation and file writing. ([[1]](https://github.com/opencodeco/validgen/pull/37/files#diff-9728e9b6a97707c0f2346e4c5fd741bd13be944daf36d331344a0acfdb646ab1R1-R100), [[2]](https://github.com/opencodeco/validgen/pull/37/files#diff-afd35748b7d2538c0a5a6052ba12a9319c2aaeda0328e95e131e45527daf61e1R1-R17))

Test Updates:

• Updated tests to align with the new modular structure and renamed functions (e.g., GetTestElements to DefineTestElements). ([[1]](https://github.com/opencodeco/validgen/pull/37/files#diff-8d32a9c408197046acde77ba1dfab1521cc0bc32365f0f98fa4c956dbadd3d39L1-R7), [[2]](https://github.com/opencodeco/validgen/pull/37/files#diff-2f2c97ac3d4ef9c052822c7c74f806c5bc7bebc6bbedb5fb5a299e890776a429L1-R1), [[3]](https://github.com/opencodeco/validgen/pull/37/files#diff-945128e013ade394999700244bb16023d6b90522a9b0bed73777242359fe6f31L1-R8), [[4]](https://github.com/opencodeco/validgen/pull/37/files#diff-40d01e1f757c04a3361c930f71762f16d1b092922b5482247e38deb024938d57L1-R8))
• Updated integration tests to use the new parser.Struct and validate the generated code. ([[1]](https://github.com/opencodeco/validgen/pull/37/files#diff-739ba07c8d00c05d17bdfe8fddf15e12650806d3112ed68324de3986678a171fL23-R50), [[2]](https://github.com/opencodeco/validgen/pull/37/files#diff-739ba07c8d00c05d17bdfe8fddf15e12650806d3112ed68324de3986678a171fL70-R96))

Main Application Changes:

• Refactored main.go to use the new modular structure, integrating parsing, analyzing, and code generation steps. Improved error handling and clarified command-line arguments. ([main.goL7-R33](https://github.com/opencodeco/validgen/pull/37/files#diff-2873f79a86c0d8b3335cd7731b0ecf7dd4301eb19a82ef7a1cba7589b5252261L7-R33))

[Copilot]

Pull Request Overview

This PR refactors the validgen codebase to support nested structs by introducing a modular architecture with three distinct internal packages: parser, analyzer, and codegenerator. The refactoring enhances code maintainability and separates concerns in the validation code generation pipeline.

• Splits the original monolithic validgen package into three specialized internal packages with clear responsibilities
• Introduces a processing pipeline where parser extracts structs, analyzer processes validation tags, and codegenerator creates validation code
• Updates the main application to use the new modular architecture with improved error handling

Reviewed Changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
main.go	Refactored to use new modular pipeline with separate parsing, analysis, and code generation steps
validgen/*.go	Removed original monolithic files (struct.go, if_code.go, find_files.go, code_generator.go)
internal/parser/*.go	New parser module for extracting Go structs and fields from source files
internal/analyzer/*.go	New analyzer module for processing validation tags and creating structured validation rules
internal/codegenerator/*.go	New code generator module for creating validation functions with template-based generation

[Copilot]

The function parameter order has changed from the original GetTestElements(fieldName, fieldValidation, fieldType) to DefineTestElements(fieldName, fieldType, fieldValidation). This inconsistency in parameter ordering could cause confusion and maintainability issues. Consider maintaining consistent parameter ordering across the codebase.

[Copilot]

The test struct field order has been changed to match the new function signature, but this creates inconsistency with string tests where the original order is maintained. For better maintainability, all test files should use consistent field ordering.