BigPicture: Validate Architecture

Do not tell the rules, define them.

BigPicture is a tool to validate the architecture of project. It can be used in Continuous Integration (CI) pipelines to validate the architecture of the project like in the .github/workflows/codequality.yml.

Why do we need this tool?

There are many rules to define the architecture of a project and it is hard to keep them in mind. For instance,

• In a layered architecture, a package can not import a package from the upper layer.
• In a hexagonal architecture, a package can not import a package from the outer layer.
• A package can not have a file which has more than 100 lines.
• A package can not have a function which has more than 20 lines.

BigPicture allows you to define these rules in a .bigpicture.json file and validate the architecture of the project.

Supported Languages

• Go
• Python
• Java
• C# (Under Development)
• JS (Under Development)

---

• Installation
  • Install with Go
  • Install on Linux
  • Install on Macos
• Usage
  • Server
  • Validate
  • .bigpicture.json File
• Validators
  • NoImportValidator
  • LineCountValidator
  • FunctionValidator
  • InstabilityValidator
  • FileNameValidator
  • SizeValidator
• Contribution

Installation

Install with Go

go install github.com/ismailbayram/bigpicture@1.2.2

Install on Linux

curl -L https://github.com/ismailbayram/bigpicture/releases/download/1.2.2/bigpicture-amd64-linux -o /usr/local/bin/bigpicture
chmod +x /usr/local/bin/bigpicture

Install on Macos

curl -L https://github.com/ismailbayram/bigpicture/releases/download/1.2.2/bigpicture-amd64-darwin -o /usr/local/bin/bigpicture
chmod +x /usr/local/bin/bigpicture

Usage

Server

Runs a server on port 44525. Architecture of the project can be seen on the browser.

bigpicture server

Validate

Validates the architecture of the project according to the rules defined in the .bigpicture.json file.

bigpicture validate

.bigpicture.json File

.bigpicture.json file is used to define the rules. It should be in the root directory of the project.

{
    "lang": "go",
    "port": 44525,
    "ignore": [
        "web"
    ],
    "validators": [
        ...
    ]
}

root_dir: Let's say that you have java project and its structure is like this:

src
├── main
├──├── java

But imports are like this:

import com.example.project

In this case, you should define the root directory of the project as /src/main/java/ in order to bigpicture build import maps correctly. Do not forget / both at the beginning and the end of the path.

Note: Supported for Java and Python.

lang: BigPicture sometimes fails on detecting language of the project. You can define the language of the project.

port: Port number of the server. Default value is 44525.

ignore: Directories to ignore. Default value is empty. For instance in this project web directory includes non-go files, thus it should be ignored.

validators: List of validators. Default value is empty. See Validators section for more information.

Validators

NoImportValidator

Checks if the package imports the given package. It can be used in layered architectures.

Example 1: For instance, in this project, /internal/config package can not import any other package.

{
    "type": "no_import",
    "args": {
        "from": "/internal/config",
        "to": "*"
    }
}

Example 2: For instance, in this project, /internal/validator package can not import any package in the /internal/browser package.

{
    "type": "no_import",
    "args": {
        "from": "/internal/validator",
        "to": "/internal/browser"
    }
}

LineCountValidator

Checks if the package has files which have more than the given number of lines.

Example: For instance, in this project, /internal/browser package can not have files which have more than 100 lines.

{
    "type": "line_count",
    "args": {
        "module": "/internal/browser",
        "max": 100,
        "ignore": ["*_test.go", "test/*.go"]
    }
}

FunctionValidator

Checks if the package has functions which have more than the given number of lines.

Example: For instance, in this project, /internal/browser package can not have functions which have more than 10 lines.

{
    "type": "function",
    "args": {
        "module": "/internal",
        "max_line_count": 50,
        "ignore": ["*_test.go", "test/*.go"]
    }
}

InstabilityValidator

Checks if the instability metric of a package according to its directory is more than the given number.

Instability Calculation:

Package A is imported by 3 packages and it imports 2 packages. Instability metric of the package A is 2 / (2 + 3) = 0.4.

Example: For instance, in this project, /internal/graph package can not have instability metric more than 0.5.

{
    "type": "instability",
    "args": {
        "module": "/internal/graph",
        "max": 0.5
    }
}

FileNameValidator

Checks if the package has files which do not match the given regular expression.

{
    "type": "file_name",
    "args": {
        "module": "/internal",
        "max_length": 12,
        "regexp": "^[a-z]+$",
        "ignore": [
            "*_test.go"
        ]
    }
}

SizeValidator

Checks the percentage size of the packages under the given directory according to the lines of code.

{
    "type": "size",
    "args": {
        "module": "/internal",
        "max": 25
    }
}

Contribution

There are many ways in which you can participate in this project, for example:

• Implement a new validator in /internal/validator directory.
• Implement a new language support in /internal/browser directory.