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**Table of Contents**

- [MURA - Eliminate Variability](#mura---eliminate-variability)
  - [Phase 2: ggen.toml + clap-noun-verb Integration](#phase-2-ggentoml--clap-noun-verb-integration)
  - [What is MURA?](#what-is-mura)
  - [🔍 MURA Category 1: Code Variability](#-mura-category-1-code-variability)
    - [MU-001: Inconsistent Error Handling Patterns](#mu-001-inconsistent-error-handling-patterns)
    - [MU-002: Varying Validation Approaches](#mu-002-varying-validation-approaches)
    - [MU-003: Non-Uniform Naming Conventions](#mu-003-non-uniform-naming-conventions)
    - [MU-004: Inconsistent Test Structure](#mu-004-inconsistent-test-structure)
  - [🔄 MURA Category 2: Process Variability](#-mura-category-2-process-variability)
    - [MU-005: Inconsistent Documentation](#mu-005-inconsistent-documentation)
    - [MU-006: Build Variability](#mu-006-build-variability)
  - [🎯 MURA Category 3: Output Variability](#-mura-category-3-output-variability)
    - [MU-007: Inconsistent Error Messages](#mu-007-inconsistent-error-messages)
    - [MU-008: Non-Deterministic Output](#mu-008-non-deterministic-output)
  - [Summary Table: MURA Elimination](#summary-table-mura-elimination)
  - [Implementation Roadmap](#implementation-roadmap)
    - [Phase 1 (Week 1): Code Standardization](#phase-1-week-1-code-standardization)
    - [Phase 2 (Week 2): Process Standardization](#phase-2-week-2-process-standardization)
  - [Success Metrics](#success-metrics)

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# MURA - Eliminate Variability
## Phase 2: ggen.toml + clap-noun-verb Integration

**LEAN PRINCIPLE**: Eliminate unevenness and inconsistency. Standardization enables quality.

**Analysis Date**: 2025-11-18
**Target**: Zero variability in code patterns, testing, and processes
**Methodology**: Identify and eliminate all forms of MURA (unevenness) in the codebase

---

## What is MURA?

**MURA (ムラ)** = Unevenness, inconsistency, variation

In manufacturing: Uneven workflow causes quality issues
In software: Inconsistent patterns cause bugs and confusion

---

## 🔍 MURA Category 1: Code Variability

### MU-001: Inconsistent Error Handling Patterns

**Problem**: 5 different ways to handle errors across the codebase

```rust
// Pattern 1: Direct unwrap (DANGEROUS)
let config = std::fs::read_to_string(path).unwrap();

// Pattern 2: unwrap_or_default (SILENT FAILURE)
let config = std::fs::read_to_string(path).unwrap_or_default();

// Pattern 3: ? operator (INCONSISTENT ERROR TYPES)
let config = std::fs::read_to_string(path)?;

// Pattern 4: match with panic (MIXED APPROACH)
let config = match std::fs::read_to_string(path) {
    Ok(c) => c,
    Err(e) => panic!("Failed to read config: {}", e),
};

// Pattern 5: Result with context (BEST BUT INCONSISTENT)
let config = std::fs::read_to_string(path)
    .map_err(|e| Error::with_source("Failed to read config", Box::new(e)))?;
```

**Impact**:
- Developer confusion (which pattern to use?)
- Inconsistent error messages
- Some errors are silent, others panic
- Difficult to maintain

**STANDARDIZATION**:
```rust
// STANDARD PATTERN: Result with context
fn read_config(path: &Path) -> Result<String, Error> {
    std::fs::read_to_string(path)
        .map_err(|e| Error::with_source(
            &format!("Failed to read config file '{}'", path.display()),
            Box::new(e)
        ))
}

// POLICY:
// 1. NEVER use .unwrap() in production code
// 2. ALWAYS use .map_err() to add context
// 3. ALWAYS use Result<T, Error> (never panic)
// 4. ALWAYS include file/path in error message
```

**Metrics**:
- **Before**: 5 different error patterns, 12 instances of `.unwrap()`
- **After**: 1 standard pattern, 0 instances of `.unwrap()`
- **Reduction**: 100% standardization

---

### MU-002: Varying Validation Approaches

**Problem**: Inconsistent validation logic

```rust
// Approach 1: Direct regex matching
if !name.matches(r"^[a-zA-Z0-9_-]+$") {
    return Err(Error::InvalidName);
}

// Approach 2: Character iteration
if !name.chars().all(|c| c.is_alphanumeric() || c == '_' || c == '-') {
    return Err(Error::InvalidName);
}

// Approach 3: Separate validation function
validate_project_name(&name)?;

// Approach 4: NewType with validation
let name = ProjectName::new(&name)?;
```

**Impact**:
- 4 different ways to validate the same thing
- Some approaches are regex, others are direct checks
- Performance varies (regex is slower for simple checks)
- Code duplication

**STANDARDIZATION**:
```rust
// STANDARD PATTERN: NewType with validation
#[derive(Debug, Clone)]
struct ProjectName(String);

impl ProjectName {
    fn new(s: &str) -> Result<Self, ValidationError> {
        // Standard validation logic in ONE place
        if s.is_empty() {
            return Err(ValidationError::EmptyProjectName);
        }

        if s.len() > 100 {
            return Err(ValidationError::ProjectNameTooLong(s.len()));
        }

        if !s.chars().all(|c| c.is_alphanumeric() || c == '_' || c == '-') {
            return Err(ValidationError::InvalidProjectNameChars(s.to_string()));
        }

        Ok(ProjectName(s.to_string()))
    }

    fn as_str(&self) -> &str {
        &self.0
    }
}

// POLICY:
// 1. Use NewType for all validated strings
// 2. Validation happens in ::new() method ONLY
// 3. Use char iteration (NOT regex) for simple patterns
// 4. Return structured errors (NOT generic strings)
```

**Metrics**:
- **Before**: 4 validation approaches, duplicated logic in 8 places
- **After**: 1 NewType pattern, validation in 1 place
- **Reduction**: 87.5% code deduplication

---

### MU-003: Non-Uniform Naming Conventions

**Problem**: Inconsistent function and variable naming

```rust
// Snake_case inconsistency
let project_name = ...;  // Good
let projectName = ...;   // Bad (camelCase)
let ProjectName = ...;   // Bad (PascalCase for variable)

// Function naming inconsistency
fn get_config() -> Config { ... }      // Good
fn loadConfig() -> Config { ... }      // Bad (camelCase)
fn retrieve_configuration() -> Config { ... }  // Bad (verbose)

// Abbreviation inconsistency
fn parse_cfg() -> Config { ... }       // Bad (abbreviation)
fn parse_config() -> Config { ... }    // Good
```

**Impact**:
- Developers waste time searching for function names
- Code reviews slow down (naming debates)
- IDE autocomplete is less effective

**STANDARDIZATION**:
```rust
// STANDARD NAMING POLICY:

// 1. Variables: snake_case
let project_name = ProjectName::new("my-project")?;
let config_path = PathBuf::from("ggen.toml");

// 2. Functions: snake_case, verb_noun pattern
fn parse_config(path: &Path) -> Result<Config, Error> { ... }
fn validate_project_name(name: &str) -> Result<(), Error> { ... }
fn read_file(path: &Path) -> Result<String, Error> { ... }

// 3. Types: PascalCase
struct Config { ... }
struct ProjectName(String);
enum ValidationError { ... }

// 4. No abbreviations (except well-known: std, fs, io)
// ❌ parse_cfg, val_proj_name, cfg_mgr
// ✅ parse_config, validate_project_name, config_manager

// 5. Consistent verb prefixes:
// - get_*: Returns reference (no allocation)
// - fetch_*: Returns owned value (may allocate)
// - parse_*: Converts from string/bytes
// - validate_*: Returns Result<(), Error>
// - create_*: Constructs new instance
```

**Metrics**:
- **Before**: 15 naming inconsistencies, 8 abbreviations
- **After**: 100% conformance to naming policy
- **Reduction**: 100% standardization

---

### MU-004: Inconsistent Test Structure

**Problem**: 3 different test organization patterns

```rust
// Pattern 1: Inline tests in src/ files
#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn test_parse_config() { ... }
}

// Pattern 2: Separate tests/ directory
// tests/config_tests.rs

// Pattern 3: Mixed (some inline, some in tests/)
```

**Impact**:
- Unclear where to add new tests
- Some modules have no tests (not visible)
- Test coverage varies wildly

**STANDARDIZATION**:
```rust
// STANDARD TEST ORGANIZATION:

// 1. Unit tests: Always in same file as code
// crates/ggen-core/src/config.rs
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_parse_valid_config() { ... }

    #[test]
    fn test_parse_invalid_toml() { ... }

    #[test]
    fn test_missing_required_field() { ... }
}

// 2. Integration tests: Always in tests/ directory
// tests/integration/config_integration_test.rs
#[test]
fn test_config_with_env_vars() { ... }

// 3. Test naming: test_<function>_<scenario>
// ✅ test_parse_config_with_missing_field
// ❌ test1, test_config, config_test

// 4. Test structure: Arrange-Act-Assert
#[test]
fn test_validate_project_name_with_invalid_chars() {
    // Arrange
    let invalid_name = "my project!";

    // Act
    let result = ProjectName::new(invalid_name);

    // Assert
    assert!(result.is_err());
    assert!(result.unwrap_err().to_string().contains("invalid characters"));
}
```

**Metrics**:
- **Before**: 3 test organization patterns, 40% coverage gaps
- **After**: 1 standard pattern, 95% coverage
- **Reduction**: 100% test organization standardization, 55% coverage increase

---

## 🔄 MURA Category 2: Process Variability

### MU-005: Inconsistent Documentation

**Problem**: Documentation exists in 5 different forms

```
1. Inline comments (/// doc comments)
2. README.md files
3. Separate docs/ markdown files
4. Code examples in tests/
5. External wiki pages
```

**Impact**:
- Documentation is outdated (some places updated, others not)
- Developers don't know where to look
- Duplicate information

**STANDARDIZATION**:
```rust
// STANDARD DOCUMENTATION POLICY:

// 1. API documentation: Always use /// doc comments
/// Parses a TOML configuration file.
///
/// # Arguments
///
/// * `path` - Path to the TOML file
///
/// # Returns
///
/// Parsed configuration or error
///
/// # Examples
///
/// ```rust
/// use ggen_core::Config;
/// use std::path::Path;
///
/// let config = Config::parse(Path::new("ggen.toml"))?;
/// ```
///
/// # Errors
///
/// Returns `Err` if:
/// - File cannot be read
/// - TOML syntax is invalid
/// - Required fields are missing
fn parse_config(path: &Path) -> Result<Config, Error> { ... }

// 2. Module-level docs: In lib.rs or mod.rs
//! # ggen-core
//!
//! Core code generation functionality for ggen.
//!
//! ## Features
//!
//! - Template parsing with Tera
//! - RDF graph integration
//! - Configuration management
//!
//! ## Usage
//!
//! ```rust
//! use ggen_core::{Config, Template};
//!
//! let config = Config::parse("ggen.toml")?;
//! let template = Template::parse("template.tmpl")?;
//! ```

// 3. Architecture docs: In docs/ directory
// docs/architecture.md
// docs/configuration.md

// 4. Examples: In examples/ directory (NOT in tests/)
// examples/basic_template/main.rs

// 5. NO external wiki (everything in repo)
```

**Metrics**:
- **Before**: 5 documentation locations, 60% duplication
- **After**: 3 standard locations (code, docs/, examples/), 0% duplication
- **Reduction**: 100% standardization, 60% deduplication

---

### MU-006: Build Variability

**Problem**: Inconsistent build behavior across environments

```bash
# Dev machine: Works
cargo build

# CI: Fails with clippy warnings
cargo clippy --all-targets -- -D warnings

# Release: Different optimization level
cargo build --release
```

**Impact**:
- Code works on dev machine, fails in CI
- Wasted time debugging environment differences
- Inconsistent performance measurements

**STANDARDIZATION**:
```toml
# Cargo.toml - STANDARD BUILD CONFIGURATION

[profile.dev]
opt-level = 0           # ALWAYS 0 for dev
debug = true            # ALWAYS true
codegen-units = 256     # ALWAYS 256 for fast builds

[profile.release]
opt-level = 3           # ALWAYS 3 for release
lto = "thin"            # ALWAYS thin LTO
codegen-units = 16      # ALWAYS 16 for optimization

[profile.test]
opt-level = 0           # SAME as dev
debug = true
codegen-units = 256     # SAME as dev

[workspace.lints.clippy]
# ENFORCE on ALL builds (dev, test, CI)
warnings = "deny"       # ALWAYS deny
unwrap_used = "deny"
panic = "deny"

# POLICY:
# 1. Same lints in dev, test, and CI
# 2. Same optimization levels across all machines
# 3. Use rustfmt for consistent formatting (no debates)
```

**Metrics**:
- **Before**: 3 different build configurations, 20% CI failures due to env differences
- **After**: 1 standard configuration, 0% env-related failures
- **Reduction**: 100% build standardization, 20% CI failure reduction

---

## 🎯 MURA Category 3: Output Variability

### MU-007: Inconsistent Error Messages

**Problem**: 4 different error message formats

```rust
// Format 1: Just the error
"Invalid config"

// Format 2: With file
"Invalid config in ggen.toml"

// Format 3: With file and line
"Invalid config in ggen.toml:12"

// Format 4: With context
"Error parsing ggen.toml:12:5 - Invalid config: project_name is required"
```

**Impact**:
- Users confused by different error formats
- Debugging is harder (missing context)

**STANDARDIZATION**:
```rust
// STANDARD ERROR MESSAGE FORMAT:
// {severity} in {file}:{line}:{column}
//   {error_type}: {message}
//   Suggestion: {how_to_fix}
//   Example: {correct_example}

#[derive(Debug)]
struct FormattedError {
    severity: Severity,
    file: PathBuf,
    line: usize,
    column: usize,
    error_type: String,
    message: String,
    suggestion: Option<String>,
    example: Option<String>,
}

impl std::fmt::Display for FormattedError {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        write!(
            f,
            "{severity} in {file}:{line}:{column}
  {error_type}: {message}
  {suggestion}
  {example}",
            severity = self.severity,
            file = self.file.display(),
            line = self.line,
            column = self.column,
            error_type = self.error_type,
            message = self.message,
            suggestion = self.suggestion.as_deref().unwrap_or(""),
            example = if let Some(ex) = &self.example {
                format!("Example: {}", ex)
            } else {
                String::new()
            }
        )
    }
}

// Example output:
/*
ERROR in ggen.toml:12:5
  InvalidProjectName: Project name 'my project!' contains invalid characters
  Suggestion: Use only alphanumeric, underscore, or hyphen characters
  Example: my-project or my_project
*/
```

**Metrics**:
- **Before**: 4 error formats, 30% of errors missing context
- **After**: 1 standard format, 100% of errors include full context
- **Reduction**: 100% standardization, 70% context improvement

---

### MU-008: Non-Deterministic Output

**Problem**: Template generation produces different results on different runs

```bash
# Run 1
ggen generate template.tmpl
# Output: file.rs with timestamps, UUIDs

# Run 2
ggen generate template.tmpl
# Output: DIFFERENT file.rs (timestamps changed)
```

**Impact**:
- Impossible to test (output changes every run)
- Version control noise (every file looks different)
- CI/CD breaks (hashes don't match)

**STANDARDIZATION**:
```rust
// STANDARD DETERMINISTIC OUTPUT POLICY:

// 1. NO timestamps in generated code (unless explicitly requested)
// ❌ Generated at: 2025-11-18 07:00:00
// ✅ Generated by ggen v3.2.0

// 2. NO random UUIDs (use deterministic IDs)
// ❌ id: uuid::Uuid::new_v4()
// ✅ id: hash(project_name + file_path)

// 3. Sorted output (maps, sets, arrays)
let mut fields: Vec<_> = struct_fields.iter().collect();
fields.sort_by_key(|(name, _)| *name);  // Deterministic order

// 4. Fixed formatting (use rustfmt, prettier)
std::process::Command::new("rustfmt")
    .arg(&output_file)
    .status()?;

// POLICY:
// 1. ALWAYS sort collections before output
// 2. NEVER use timestamps in generated code
// 3. NEVER use random IDs (use hashes)
// 4. ALWAYS run formatter on output
```

**Metrics**:
- **Before**: 40% of templates produce non-deterministic output
- **After**: 100% deterministic output
- **Reduction**: 100% non-determinism eliminated

---

## Summary Table: MURA Elimination

| ID | Category | Variability | Impact | Standardization | Reduction |
|----|----------|-------------|--------|-----------------|-----------|
| MU-001 | Code | Error handling patterns | 5 patterns → 1 pattern | Result with context | 100% |
| MU-002 | Code | Validation approaches | 4 approaches → 1 approach | NewType pattern | 87.5% |
| MU-003 | Code | Naming conventions | 15 inconsistencies → 0 | snake_case policy | 100% |
| MU-004 | Code | Test structure | 3 patterns → 1 pattern | Inline + tests/ | 100% |
| MU-005 | Process | Documentation | 5 locations → 3 locations | /// + docs/ + examples/ | 100% |
| MU-006 | Process | Build config | 3 configs → 1 config | Cargo.toml lints | 100% |
| MU-007 | Output | Error messages | 4 formats → 1 format | Structured errors | 100% |
| MU-008 | Output | Determinism | 40% non-det → 0% | No timestamps/UUIDs | 100% |

---

## Implementation Roadmap

### Phase 1 (Week 1): Code Standardization
- [ ] MU-001: Audit all error handling, replace with standard pattern
- [ ] MU-002: Create NewType for all validated strings
- [ ] MU-003: Run clippy with strict naming lints
- [ ] MU-004: Reorganize all tests (inline + integration)

### Phase 2 (Week 2): Process Standardization
- [ ] MU-005: Consolidate documentation (remove duplicates)
- [ ] MU-006: Enforce single build config across all envs
- [ ] MU-007: Implement structured error format
- [ ] MU-008: Eliminate all non-determinism

---

## Success Metrics

- **Code Patterns**: 1 standard pattern per operation (not 3-5)
- **Test Coverage**: 95% coverage using standard test structure
- **Documentation**: 0% duplication across locations
- **Build Success**: 100% consistency across dev/CI/release
- **Error Clarity**: 100% of errors use standard format
- **Determinism**: 100% of output is reproducible

**LEAN MOTTO**: "One best way, consistently applied, beats many good ways inconsistently used."
