In software development, documentation is crucial for maintaining clarity and consistency across projects. Documenting software serves multiple purposes, such as preserving knowledge, facilitating collaboration, and enhancing future maintenance efforts. When software is well-documented, developers can understand the system’s architecture, functionalities, and the rationale behind specific design choices. This comprehension is essential for current team members and future developers who may work on the project.
One of the primary reasons for documenting software is to ensure that knowledge is not lost. In any development team, turnover is inevitable. Team members come and go, and their knowledge and understanding of the system might leave as well. Comprehensive documentation is a repository of this knowledge, allowing new developers to get up to speed quickly. It provides a reference point that can save time and reduce the risk of misinterpretation or errors during development.
Documenting decisions made during the software development process is equally important. Whether it concerns the choice of a specific technology, design pattern, or feature implementation, each decision carries underlying assumptions and constraints. By documenting these decisions, developers can capture the context and reasoning that led to a particular choice. This practice is invaluable when revisiting decisions months or even years later, especially when the original decision-makers can no longer explain their thought processes. It helps avoid the “Why did they do this?” scenario that often plagues projects with poor documentation.
Moreover, documented decisions provide a historical record that can be reviewed when considering changes or updates to the system. For example, if a particular architectural decision was made to work around a limitation that no longer exists, knowing the original rationale can help developers make informed decisions about whether to revise that approach. This historical context can also prevent repeated mistakes and ensure the team learns from past experiences.
However, many teams find themselves with a substantial amount of software but little to no documentation. Addressing this issue requires a strategic approach. First, prioritise documenting the most critical parts of the system. Focus on the core architecture, major components, and any particularly complex or non-obvious areas of the codebase. Use a combination of high-level overviews and detailed explanations to cover both the broad strokes and the finer details.
Next, implement a process for continuous documentation. Encourage developers to document as they code, integrating this practice into their workflow. Tools like wikis, markdown files in the repository, and automated documentation generators can help streamline this process. Adopting a template for documenting decisions, similar to the one mentioned in the original article, can standardise how information is captured and presented.
Conducting documentation sprints can be effective for existing software with poor documentation. These are focused periods where the team works together to create and improve documentation. Pairing developers with technical writers or designating specific team members to oversee documentation efforts can also enhance the quality and consistency of the output.
Some tools can help automate documentation. These tools can assist in generating documentation from code comments, extracting information from existing codebases, and maintaining up-to-date documentation. Here are some solutions:
Doxygen
Doxygen is a popular documentation generator for various programming languages, including C++, C, Java, Python, and others. It generates documentation from annotated source code and supports output formats like HTML, LaTeX, and PDF.
Features include automatic extraction of code comments, support for various programming languages, and integration with version control systems.
Useful for generating detailed reference manuals directly from source code.
Sphinx
Sphinx is a documentation generator primarily used for Python projects. It converts reStructuredText files into HTML websites and other formats.
Supports extensions, integration with code comments, and automatic API documentation generation with autodoc.
Ideal for Python projects needing comprehensive documentation and static site generation.
Javadoc
Javadoc is a tool provided by Oracle for generating API documentation in HTML format from Java source code.
Generates documentation from code comments, supports standard HTML documentation structure.
Specifically designed for Java projects, providing standardised and easily accessible documentation.
Swagger/OpenAPI
Swagger, part of the OpenAPI specification, is a framework for API documentation. It provides tools for designing, building, and documenting RESTful APIs.
Interactive API documentation, code generation, API testing.
Essential for projects involving RESTful APIs, facilitating both development and usage documentation.
MkDocs
MkDocs is a static site generator geared towards project documentation, written in Markdown.
Simple to setup and configure, supports Markdown, themes, and plugins.
Suitable for general project documentation, particularly if Markdown is preferred.
Typedoc
Typedoc is a documentation generator for TypeScript projects, creating a documentation website based on TypeScript comments.
Generates documentation from TypeScript source files, supports themes.
Ideal for TypeScript projects requiring structured and detailed documentation.
Redoc
Redoc is an OpenAPI/Swagger-generated API documentation tool with a focus on providing a clean and readable UI.
Customizable and responsive API documentation, supports OpenAPI 3.0.
Enhances the presentation of API documentation, making it user-friendly and interactive.
Asciidoctor
Asciidoctor is a fast text processor and publishing toolchain for converting AsciiDoc content into HTML5, DocBook, PDF, and other formats.
Rich formatting capabilities, extensions, and integrations with various tools.
Useful for projects needing highly formatted and multi-format documentation.
PlantUML
PlantUML is a tool that allows users to create diagrams from plain text descriptions.
Supports a variety of diagram types, integrates with documentation tools.
Useful for generating visual documentation, such as UML diagrams, sequence diagrams, and flowcharts.
DocFX
DocFX is an open-source documentation generator for .NET projects that can produce documentation from source code and markdown files.
Generates API documentation from .NET source code, supports Markdown and custom templates.
Ideal for .NET projects needing comprehensive documentation.