[SAOC 2024] SARIF Library and Outputs - Weekly Update #3

[Royal Simpson Pinto]

## Summary of Progress (September 30 – October 6)

In the third week of Milestone 1, I worked on building a library 
to represent SARIF and serialize it into JSON, following my 
mentor’s suggestion. I created multiple drafts of SARIF outputs, 
refining the structure and improving the details with each 
iteration. These drafts have helped me fine-tune the SARIF format 
for DMD’s error reporting, and I ran unit tests to validate the 
structure along the way.

### **What I Worked On:**

#### 1. **Building a SARIF Library for JSON Serialization**
    - I created an initial version of the SARIF template that 
includes key components to represent and serialize error 
information.
    - **Key Components**:
      - **LogicalLocation and PhysicalLocation structs**: 
Represent logical (e.g., function or method) and physical (e.g., 
file, line, column) locations in code.
      - **Result struct**: Stores rule violation details and uses 
`SumType` to handle both `PhysicalLocation` and `LogicalLocation` 
flexibly.
      - **JSON Serialization**: Implemented `toJson` methods for 
all structs, enabling easy conversion of SARIF objects into JSON 
format.
    - **Unit Tests**: I created unit tests to ensure robustness, 
covering various scenarios like unusual URIs, empty values, and 
different combinations of logical and physical locations.

#### 2. **Refining SARIF Outputs Over Four Drafts**
    - I worked on multiple drafts to refine the SARIF outputs, 
progressively improving the structure and adding details to 
tailor it for DMD-specific use cases. Here’s a summary of the 
changes across the drafts:

    - **First Draft**: This was the initial version of the SARIF 
output, which included basic sections like `LogicalLocation`, 
`PhysicalLocation`, and `Result`.
      - [feat: SARIF Template, JSON 
Serialisation](https://github.com/royalpinto007/d-drafts/blob/main/sarif.d)
      - 
[sarifoutput.md](https://github.com/royalpinto007/d-drafts/blob/main/sarifoutput.md)

    - **Second Draft**: Added more detailed sections, including 
`invocation`, `tool`, and `result`. This draft provided more 
comprehensive error reporting but did not include a 
`suggestedFix`.
      - [feat: SARIF Template (second 
draft)](https://github.com/royalpinto007/d-drafts/blob/main/1sarif.d)
      - 
[1sarifoutput.md](https://github.com/royalpinto007/d-drafts/blob/main/1sarifoutput.md)

    - **Third Draft**: Introduced the `suggestedFix` section, 
which provided potential solutions for errors connected to 
specific files (e.g., `test.d`). However, I later realized that 
the `suggestedFix` wasn't practical without deeper context from 
the DMD codebase.
      - [feat: SARIF Template (third draft)- source file, 
suggestedFix
](https://github.com/royalpinto007/d-drafts/blob/main/2sarif.d)
      - 
[2sarifoutput.md](https://github.com/royalpinto007/d-drafts/blob/main/2sarifoutput.md)

    - **Fourth Draft**: Removed the `suggestedFix` section to keep 
the output simpler and more in line with how other compilers 
structure SARIF outputs. This draft focuses on clear, minimal, 
and structured error reporting.
      - [feat: SARIF Template (fourth draft)- without any 
suggestedFix
](https://github.com/royalpinto007/d-drafts/blob/main/3sarif.d)
      - 
[3sarifoutput.md](https://github.com/royalpinto007/d-drafts/blob/main/3sarifoutput.md)

#### 3. **Early Returns in the Main Function**
    - I applied early returns in the `main` function to simplify 
the code and reduce unnecessary nesting, following my mentor's 
earlier suggestion. This keeps the code cleaner and more 
maintainable.

### **Challenges:**
    - **Feasibility of `suggestedFix`**: While experimenting with 
the `suggestedFix` section in the third draft, I found that it 
wasn’t feasible without a deeper integration with DMD’s existing 
error-handling system. This led to the decision to remove it in 
the fourth draft.
    - **Balancing SARIF Details**: Finding the right level of 
detail in the SARIF outputs was challenging, but after refining 
the structure across four drafts, I achieved a balance between 
comprehensive reporting and simplicity.

### **Next Week’s Plan:**
    - Begin integrating the SARIF library with the DMD codebase, 
following my mentor’s guidance. This will involve mapping DMD’s 
error reporting system to the SARIF schema using the library I 
built.
    - Continue refining the SARIF integration based on real test 
cases from DMD.

---

This week was focused on building a library for SARIF 
representation and refining the output structure. I’m looking 
forward to integrating the SARIF library with the DMD codebase 
and making further progress on this exciting task!