feat: add change creation utilities

openspec/changes/archive/2025-12-25-add-change-manager/design.md

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+## Context
+
+This is Slice 2 of the artifact tracker POC. The goal is to provide utilities for creating change directories programmatically.
+
+**Current state:** No programmatic way to create changes. Users must manually create directories.
+
+**Proposed state:** Utility functions for change creation with name validation.
+
+## Goals / Non-Goals
+
+### Goals
+- **Add** `createChange()` function to create change directories
+- **Add** `validateChangeName()` function for kebab-case validation
+- **Enable** automation (Claude commands, scripts) to create changes
+
+### Non-Goals
+- Refactor existing CLI commands (they work fine)
+- Create abstraction layers or manager classes
+- Change how `ListCommand` or `ChangeCommand` work
+
+## Decisions
+
+### Decision 1: Simple Utility Functions
+
+**Choice**: Add functions to `src/utils/change-utils.ts` - no class.
+
+```typescript
+// src/utils/change-utils.ts
+
+export function validateChangeName(name: string): { valid: boolean; error?: string }
+
+export async function createChange(
+  projectRoot: string,
+  name: string
+): Promise<void>
+```
+
+**Why**:
+- Simple, no abstraction overhead
+- Easy to test
+- Easy to import where needed
+- Matches existing utility patterns in `src/utils/`
+
+**Alternatives considered**:
+- ChangeManager class: Rejected - over-engineered for 2 functions
+- Add to existing command: Rejected - mixes CLI with reusable logic
+
+### Decision 2: Kebab-Case Validation Pattern
+
+**Choice**: Validate names with `^[a-z][a-z0-9]*(-[a-z0-9]+)*$`
+
+Valid: `add-auth`, `refactor-db`, `add-feature-2`, `refactor`
+Invalid: `Add-Auth`, `add auth`, `add_auth`, `-add-auth`, `add-auth-`, `add--auth`
+
+**Why**:
+- Filesystem-safe (no special characters)
+- URL-safe (for future web UI)
+- Consistent with existing change naming in repo
+
+## File Changes
+
+### New Files
+- `src/utils/change-utils.ts` - Utility functions
+- `src/utils/change-utils.test.ts` - Unit tests
+
+### Modified Files
+- None
+
+## Risks / Trade-offs
+
+| Risk | Mitigation |
+|------|------------|
+| Function might not cover all use cases | Start simple, extend if needed |
+| Naming conflicts with future work | Using clear, specific function names |

openspec/changes/archive/2025-12-25-add-change-manager/proposal.md

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+## Why
+
+There's no programmatic way to create a new change directory. Users must manually:
+1. Create `openspec/changes/<name>/` directory
+2. Create a `proposal.md` file
+3. Hope they got the naming right
+
+This is error-prone and blocks automation (e.g., Claude commands, scripts).
+
+**This proposal adds:**
+1. `createChange(projectRoot, name)` - Create change directories programmatically
+2. `validateChangeName(name)` - Enforce kebab-case naming conventions
+
+## What Changes
+
+### New Utilities
+
+| Function | Description |
+|----------|-------------|
+| `createChange(projectRoot, name)` | Creates `openspec/changes/<name>/` directory |
+| `validateChangeName(name)` | Returns `{ valid: boolean; error?: string }` |
+
+### Name Validation Rules
+
+Pattern: `^[a-z][a-z0-9]*(-[a-z0-9]+)*$`
+
+| Valid | Invalid |
+|-------|---------|
+| `add-auth` | `Add-Auth` (uppercase) |
+| `refactor-db` | `add auth` (spaces) |
+| `add-feature-2` | `add_auth` (underscores) |
+| `refactor` | `-add-auth` (leading hyphen) |
+
+### Location
+
+New file: `src/utils/change-utils.ts`
+
+Simple utility functions - no class, no abstraction layer.
+
+## Impact
+
+- **Affected specs**: None
+- **Affected code**: None (new utilities only)
+- **New files**: `src/utils/change-utils.ts`
+- **Breaking changes**: None

openspec/changes/archive/2025-12-25-add-change-manager/specs/change-creation/spec.md

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+## ADDED Requirements
+
+### Requirement: Change Creation
+The system SHALL provide a function to create new change directories programmatically.
+
+#### Scenario: Create change
+- **WHEN** `createChange(projectRoot, 'add-auth')` is called
+- **THEN** the system creates `openspec/changes/add-auth/` directory
+
+#### Scenario: Duplicate change rejected
+- **WHEN** `createChange(projectRoot, 'add-auth')` is called and `openspec/changes/add-auth/` already exists
+- **THEN** the system throws an error indicating the change already exists
+
+#### Scenario: Creates parent directories if needed
+- **WHEN** `createChange(projectRoot, 'add-auth')` is called and `openspec/changes/` does not exist
+- **THEN** the system creates the full path including parent directories
+
+#### Scenario: Invalid change name rejected
+- **WHEN** `createChange(projectRoot, 'Add Auth')` is called with an invalid name
+- **THEN** the system throws a validation error
+
+### Requirement: Change Name Validation
+The system SHALL validate change names follow kebab-case conventions.
+
+#### Scenario: Valid kebab-case name accepted
+- **WHEN** a change name like `add-user-auth` is validated
+- **THEN** validation returns `{ valid: true }`
+
+#### Scenario: Numeric suffixes accepted
+- **WHEN** a change name like `add-feature-2` is validated
+- **THEN** validation returns `{ valid: true }`
+
+#### Scenario: Single word accepted
+- **WHEN** a change name like `refactor` is validated
+- **THEN** validation returns `{ valid: true }`
+
+#### Scenario: Uppercase characters rejected
+- **WHEN** a change name like `Add-Auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Spaces rejected
+- **WHEN** a change name like `add auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Underscores rejected
+- **WHEN** a change name like `add_auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Special characters rejected
+- **WHEN** a change name like `add-auth!` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Leading hyphen rejected
+- **WHEN** a change name like `-add-auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Trailing hyphen rejected
+- **WHEN** a change name like `add-auth-` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Consecutive hyphens rejected
+- **WHEN** a change name like `add--auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`

openspec/changes/archive/2025-12-25-add-change-manager/tasks.md

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+## Phase 1: Implement Name Validation
+
+- [x] 1.1 Create `src/utils/change-utils.ts`
+- [x] 1.2 Implement `validateChangeName()` with kebab-case pattern
+- [x] 1.3 Pattern: `^[a-z][a-z0-9]*(-[a-z0-9]+)*$`
+- [x] 1.4 Return `{ valid: boolean; error?: string }`
+- [x] 1.5 Add test: valid names accepted (`add-auth`, `refactor`, `add-feature-2`)
+- [x] 1.6 Add test: uppercase rejected
+- [x] 1.7 Add test: spaces rejected
+- [x] 1.8 Add test: underscores rejected
+- [x] 1.9 Add test: special characters rejected
+- [x] 1.10 Add test: leading/trailing hyphens rejected
+- [x] 1.11 Add test: consecutive hyphens rejected
+
+## Phase 2: Implement Change Creation
+
+- [x] 2.1 Implement `createChange(projectRoot, name)`
+- [x] 2.2 Validate name before creating
+- [x] 2.3 Create parent directories if needed (`openspec/changes/`)
+- [x] 2.4 Throw if change already exists
+- [x] 2.5 Add test: creates directory
+- [x] 2.6 Add test: duplicate change throws error
+- [x] 2.7 Add test: invalid name throws validation error
+- [x] 2.8 Add test: creates parent directories if needed
+
+## Phase 3: Integration
+
+- [x] 3.1 Export functions from `src/utils/index.ts`
+- [x] 3.2 Add JSDoc comments
+- [x] 3.3 Run all tests to verify no regressions

openspec/specs/change-creation/spec.md

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+# change-creation Specification
+
+## Purpose
+Provide programmatic utilities for creating and validating OpenSpec change directories.
+## Requirements
+### Requirement: Change Creation
+The system SHALL provide a function to create new change directories programmatically.
+
+#### Scenario: Create change
+- **WHEN** `createChange(projectRoot, 'add-auth')` is called
+- **THEN** the system creates `openspec/changes/add-auth/` directory
+
+#### Scenario: Duplicate change rejected
+- **WHEN** `createChange(projectRoot, 'add-auth')` is called and `openspec/changes/add-auth/` already exists
+- **THEN** the system throws an error indicating the change already exists
+
+#### Scenario: Creates parent directories if needed
+- **WHEN** `createChange(projectRoot, 'add-auth')` is called and `openspec/changes/` does not exist
+- **THEN** the system creates the full path including parent directories
+
+#### Scenario: Invalid change name rejected
+- **WHEN** `createChange(projectRoot, 'Add Auth')` is called with an invalid name
+- **THEN** the system throws a validation error
+
+### Requirement: Change Name Validation
+The system SHALL validate change names follow kebab-case conventions.
+
+#### Scenario: Valid kebab-case name accepted
+- **WHEN** a change name like `add-user-auth` is validated
+- **THEN** validation returns `{ valid: true }`
+
+#### Scenario: Numeric suffixes accepted
+- **WHEN** a change name like `add-feature-2` is validated
+- **THEN** validation returns `{ valid: true }`
+
+#### Scenario: Single word accepted
+- **WHEN** a change name like `refactor` is validated
+- **THEN** validation returns `{ valid: true }`
+
+#### Scenario: Uppercase characters rejected
+- **WHEN** a change name like `Add-Auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Spaces rejected
+- **WHEN** a change name like `add auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Underscores rejected
+- **WHEN** a change name like `add_auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Special characters rejected
+- **WHEN** a change name like `add-auth!` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Leading hyphen rejected
+- **WHEN** a change name like `-add-auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Trailing hyphen rejected
+- **WHEN** a change name like `add-auth-` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+
+#### Scenario: Consecutive hyphens rejected
+- **WHEN** a change name like `add--auth` is validated
+- **THEN** validation returns `{ valid: false, error: "..." }`
+

src/utils/change-utils.ts

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+import path from 'path';
+import { FileSystemUtils } from './file-system.js';
+
+/**
+ * Result of validating a change name.
+ */
+export interface ValidationResult {
+  valid: boolean;
+  error?: string;
+}
+
+/**
+ * Validates that a change name follows kebab-case conventions.
+ *
+ * Valid names:
+ * - Start with a lowercase letter
+ * - Contain only lowercase letters, numbers, and hyphens
+ * - Do not start or end with a hyphen
+ * - Do not contain consecutive hyphens
+ *
+ * @param name - The change name to validate
+ * @returns Validation result with `valid: true` or `valid: false` with an error message
+ *
+ * @example
+ * validateChangeName('add-auth') // { valid: true }
+ * validateChangeName('Add-Auth') // { valid: false, error: '...' }
+ */
+export function validateChangeName(name: string): ValidationResult {
+  // Pattern: starts with lowercase letter, followed by lowercase letters/numbers,
+  // optionally followed by hyphen + lowercase letters/numbers (repeatable)
+  const kebabCasePattern = /^[a-z][a-z0-9]*(-[a-z0-9]+)*$/;
+
+  if (!name) {
+    return { valid: false, error: 'Change name cannot be empty' };
+  }
+
+  if (!kebabCasePattern.test(name)) {
+    // Provide specific error messages for common mistakes
+    if (/[A-Z]/.test(name)) {
+      return { valid: false, error: 'Change name must be lowercase (use kebab-case)' };
+    }
+    if (/\s/.test(name)) {
+      return { valid: false, error: 'Change name cannot contain spaces (use hyphens instead)' };
+    }
+    if (/_/.test(name)) {
+      return { valid: false, error: 'Change name cannot contain underscores (use hyphens instead)' };
+    }
+    if (name.startsWith('-')) {
+      return { valid: false, error: 'Change name cannot start with a hyphen' };
+    }
+    if (name.endsWith('-')) {
+      return { valid: false, error: 'Change name cannot end with a hyphen' };
+    }
+    if (/--/.test(name)) {
+      return { valid: false, error: 'Change name cannot contain consecutive hyphens' };
+    }
+    if (/[^a-z0-9-]/.test(name)) {
+      return { valid: false, error: 'Change name can only contain lowercase letters, numbers, and hyphens' };
+    }
+    if (/^[0-9]/.test(name)) {
+      return { valid: false, error: 'Change name must start with a letter' };
+    }
+
+    return { valid: false, error: 'Change name must follow kebab-case convention (e.g., add-auth, refactor-db)' };
+  }
+
+  return { valid: true };
+}
+
+/**
+ * Creates a new change directory.
+ *
+ * @param projectRoot - The root directory of the project (where `openspec/` lives)
+ * @param name - The change name (must be valid kebab-case)
+ * @throws Error if the change name is invalid
+ * @throws Error if the change directory already exists
+ *
+ * @example
+ * // Creates openspec/changes/add-auth/
+ * await createChange('/path/to/project', 'add-auth')
+ */
+export async function createChange(
+  projectRoot: string,
+  name: string
+): Promise<void> {
+  // Validate the name first
+  const validation = validateChangeName(name);
+  if (!validation.valid) {
+    throw new Error(validation.error);
+  }
+
+  // Build the change directory path
+  const changeDir = path.join(projectRoot, 'openspec', 'changes', name);
+
+  // Check if change already exists
+  if (await FileSystemUtils.directoryExists(changeDir)) {
+    throw new Error(`Change '${name}' already exists at ${changeDir}`);
+  }
+
+  // Create the directory (including parent directories if needed)
+  await FileSystemUtils.createDirectory(changeDir);
+}

src/utils/index.ts

@@ -1,2 +1,3 @@
-// Shared utilities will be implemented here
-export {};
+// Shared utilities
+export { validateChangeName, createChange } from './change-utils.js';
+export type { ValidationResult } from './change-utils.js';