[WIP] Extract magic constants from compiler_yaml.go to constants package

[Copilot]

Extract Magic Constants to Centralized Constants Package

This PR extracts hardcoded magic values from compiler code to the centralized constants package, improving maintainability and consistency.

Implementation Plan

• Identify all magic constants in scope

  • Prompt file path: /tmp/gh-aw/aw-prompts/prompt.txt (compiler_yaml.go lines 281, 287)
  • Max patch size: 1024 (compiler_safe_outputs_config.go lines 298, 322; create_pull_request.go line 90)
  • YAML builder size: 256 * 1024 (compiler_yaml.go line 179)
  • Chunk size constants: 20900 and 21000 (compiler_yaml.go line 201)

• Add new constants to pkg/constants/constants.go

  • Add FilePath semantic type alias
  • Add ByteSize semantic type alias
  • Add PromptFilePath constant
  • Add DefaultMaxPatchSize constant
  • Add DefaultYAMLBuilderSize constant
  • Add MaxChunkSize and ChunkSizeBuffer constants

• Update compiler_yaml.go to use new constants

  • Replace hardcoded prompt file paths
  • Replace YAML builder size
  • Replace chunk size constants

• Update compiler_safe_outputs_config.go to use new constants

  • Replace maxPatchSize default value (2 occurrences)

• Update create_pull_request.go to use new constants

  • Replace maxPatchSize default value

• Run tests and validation

  • Run make fmt
  • Run make test-unit
  • Run make lint
  • Run make agent-finish

• Request code review

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Code Quality] Extract magic constants from compiler_yaml.go to centralized constants package</issue_title>
<issue_description>### Description

The compiler_yaml.go file contains hardcoded magic values (file paths, size limits, constants) that should be extracted to a centralized constants package. This makes the code harder to maintain and creates inconsistencies when the same values are used across multiple files.

Problems Identified

Hardcoded Values Found:

1. File Paths:

   • /tmp/gh-aw/aw-prompts/prompt.txt (line 257) - appears multiple times
   • Should be in PathConstants

2. Size Limits:

   • maxPatchSize := 1024 // default 1024 KB (line 298) - should be constant
   • Should be DefaultMaxPatchSize = 1024

3. Other Magic Values:

   • Step IDs and output names scattered throughout
   • Should be defined as constants for easy reference

Impact

• Maintainability: Must search for all occurrences to change values
• Consistency: Risk of different values in different locations
• Documentation: Hard to find canonical values
• Type Safety: Strings/ints don't convey semantic meaning

Suggested Changes

1. Create centralized constants in pkg/constants/paths.go:

const (
    PromptFilePath = "/tmp/gh-aw/aw-prompts/prompt.txt"
    DefaultMaxPatchSize = 1024  // KB
)

2. Replace hardcoded values in compiler_yaml.go:

// Before:
maxPatchSize := 1024

// After:
maxPatchSize := constants.DefaultMaxPatchSize

3. Extract step IDs and output names (if applicable):

const (
    SetupStepID = "setup"
    AgentStepID = "agent"
    // ... etc
)

Files Affected

• pkg/workflow/compiler_yaml.go - Replace hardcoded values
• pkg/constants/paths.go (new) - Or add to existing constants file
• Other files using same constants - Update imports

Success Criteria

• All magic values in compiler_yaml.go extracted to constants
• Constants defined with semantic type aliases where appropriate
• All references updated to use constants
• No hardcoded file paths or size limits remaining
• All tests pass without modification
• Documentation updated if constants are user-configurable

Source

Extracted from Daily Compiler Code Quality Report - 2026-01-30

Finding: Issue #2 - Hardcoded Magic Values (Low Priority)

Priority

Low-Medium - Improves code maintainability and reduces technical debt, but not blocking functionality.

Estimated Effort

1-2 hours (extraction + testing)

AI generated by Discussion Task Miner - Code Quality Improvement Agent

• expires on Feb 13, 2026, 5:22 AM UTC

Comments on the Issue (you are @copilot in this section)

• Fixes [Code Quality] Extract magic constants from compiler_yaml.go to centralized constants package #12678

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.