fix(ccusage): extract session ID from filename instead of directory name

[majiayu000]

Fixes session ID extraction when project directories start with hyphens (e.g., -home-claude-user). The session ID is now correctly extracted from the JSONL filename instead of the parent directory.

Fixes #560

Summary by CodeRabbit

• Refactor

  • Improved session data file handling by deriving session identifiers from filenames instead of directory structure.
  • Enhanced project path extraction logic to better handle directory naming conventions, including support for hyphen-prefixed directories.

• Tests

  • Updated test fixtures to reflect new file-naming conventions for session data.
  • Added regression tests for project directory path handling.

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[coderabbitai]

📝 Walkthrough

Walkthrough

The data loader now extracts session IDs from JSONL filenames (removing the .jsonl extension) rather than inferring them from directory structures. A new helper function extractProjectFromPath() extracts the project name from file paths. Test fixtures were updated to reflect the new file-naming convention and session organization structure.

Changes

Cohort / File(s)	Summary
Data Loader Core Logic apps/ccusage/src/data-loader.ts	Modified loadSessionData to derive sessionId from JSONL filename basename and projectPath via new extractProjectFromPath() helper; added exported helper function extractProjectFromPath(jsonlPath: string): string for project name extraction from file paths.
Test Fixtures & Validation Test files (related to data-loader)	Updated test data and expectations to align with new file-naming convention (sessionX.jsonl) and project layout; added regression test coverage for project directories starting with hyphens.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested reviewers

• ryoppippi

Poem

🐰 A rabbit hops through tangled paths,
Where filenames once led us astray,
Now sessions bloom from .jsonl names,
And hyphens can't obscure the way—
Each session found, no more stray hay! 🥕

Pre-merge checks and finishing touches

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: extracting session ID from filename instead of directory name to fix aggregation issues.
Linked Issues check	✅ Passed	The PR addresses issue #560 by implementing the proposed short-term fix: extracting session ID from JSONL filename instead of directory name, preventing misinterpretation of hyphen-prefixed directories.
Out of Scope Changes check	✅ Passed	All changes are directly related to fixing session ID extraction logic and updating related tests; no out-of-scope modifications detected.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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📜 Recent review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 6335626 and b325647.

📒 Files selected for processing (1)

• apps/ccusage/src/data-loader.ts

🧰 Additional context used

📓 Path-based instructions (7)

apps/ccusage/src/**/*.ts

📄 CodeRabbit inference engine (apps/ccusage/CLAUDE.md)

apps/ccusage/src/**/*.ts: Write tests in-source using if (import.meta.vitest != null) blocks instead of separate test files
Use Vitest globals (describe, it, expect) without imports in test blocks
In tests, use current Claude 4 models (sonnet-4, opus-4)
Use fs-fixture with createFixture() to simulate Claude data in tests
Only export symbols that are actually used by other modules
Do not use console.log; use the logger utilities from src/logger.ts instead

Files:

• apps/ccusage/src/data-loader.ts

apps/ccusage/**/*.ts

📄 CodeRabbit inference engine (apps/ccusage/CLAUDE.md)

apps/ccusage/**/*.ts: NEVER use await import() dynamic imports anywhere (especially in tests)
Prefer @praha/byethrow Result type for error handling instead of try-catch
Use .ts extensions for local imports (e.g., import { foo } from './utils.ts')

Files:

• apps/ccusage/src/data-loader.ts

**/*.{ts,tsx,js,jsx}

📄 CodeRabbit inference engine (CLAUDE.md)

**/*.{ts,tsx,js,jsx}: Use ESLint for linting and formatting with tab indentation and double quotes
No console.log allowed except where explicitly disabled with eslint-disable; use logger.ts instead
Use file paths with Node.js path utilities for cross-platform compatibility
Use variables starting with lowercase (camelCase) for variable names
Can use UPPER_SNAKE_CASE for constants

Files:

• apps/ccusage/src/data-loader.ts

**/*.ts{,x}

📄 CodeRabbit inference engine (CLAUDE.md)

Use TypeScript with strict mode and bundler module resolution

Files:

• apps/ccusage/src/data-loader.ts

**/*.{ts,tsx}

📄 CodeRabbit inference engine (CLAUDE.md)

**/*.{ts,tsx}: Use .ts extensions for local file imports (e.g., import { foo } from './utils.ts')
Prefer @praha/byethrow Result type over traditional try-catch for functional error handling
Use Result.try() for wrapping operations that may throw (JSON parsing, etc.)
Use Result.isFailure() for checking errors (more readable than !Result.isSuccess())
Use early return pattern (if (Result.isFailure(result)) continue;) instead of ternary operators when checking Results
Keep traditional try-catch only for file I/O with complex error handling or legacy code that's hard to refactor
Always use Result.isFailure() and Result.isSuccess() type guards for better code clarity
Use uppercase (PascalCase) for type names
Only export constants, functions, and types that are actually used by other modules - internal constants used only within the same file should NOT be exported
In-source testing pattern: write tests directly in source files using if (import.meta.vitest != null) blocks
CRITICAL: DO NOT use await import() dynamic imports anywhere in the codebase - this causes tree-shaking issues
CRITICAL: Never use dynamic imports with await import() in vitest test blocks - this is particularly problematic for test execution
Vitest globals (describe, it, expect) are enabled and available without imports since globals are configured
Create mock data using fs-fixture with createFixture() for Claude data directory simulation in tests
All test files must use current Claude 4 models (claude-sonnet-4-20250514, claude-opus-4-20250514), not outdated Claude 3 models
Model names in tests must exactly match LiteLLM's pricing database entries

Files:

• apps/ccusage/src/data-loader.ts

**/data-loader.ts

📄 CodeRabbit inference engine (CLAUDE.md)

Silently skip malformed JSONL lines during parsing in data loading operations

Files:

• apps/ccusage/src/data-loader.ts

**/*.{ts,tsx,json}

📄 CodeRabbit inference engine (CLAUDE.md)

Claude model naming convention: claude-{model-type}-{generation}-{date} (e.g., claude-sonnet-4-20250514, NOT claude-4-sonnet-20250514)

Files:

• apps/ccusage/src/data-loader.ts

🧠 Learnings (11)

📓 Common learnings

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-11-25T14:42:34.734Z
Learning: For app directories in commits, use the app directory name as scope (e.g., `feat(ccusage):`, `fix(mcp):`)

📚 Learning: 2025-09-18T16:06:37.474Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/ccusage/CLAUDE.md:0-0
Timestamp: 2025-09-18T16:06:37.474Z
Learning: Applies to apps/ccusage/src/**/*.ts : Use `fs-fixture` with `createFixture()` to simulate Claude data in tests

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-09-18T16:06:37.474Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/ccusage/CLAUDE.md:0-0
Timestamp: 2025-09-18T16:06:37.474Z
Learning: Applies to apps/ccusage/src/**/*.ts : In tests, use current Claude 4 models (sonnet-4, opus-4)

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-11-25T14:42:34.734Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-11-25T14:42:34.734Z
Learning: Applies to **/data-loader.ts : Silently skip malformed JSONL lines during parsing in data loading operations

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-09-18T16:06:37.474Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/ccusage/CLAUDE.md:0-0
Timestamp: 2025-09-18T16:06:37.474Z
Learning: Applies to apps/ccusage/src/**/*.ts : Write tests in-source using `if (import.meta.vitest != null)` blocks instead of separate test files

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-09-18T16:06:37.474Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/ccusage/CLAUDE.md:0-0
Timestamp: 2025-09-18T16:06:37.474Z
Learning: Applies to apps/ccusage/**/*.ts : Use `.ts` extensions for local imports (e.g., `import { foo } from './utils.ts'`)

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-11-25T14:42:34.734Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-11-25T14:42:34.734Z
Learning: Applies to **/*.{ts,tsx,json} : Claude model naming convention: `claude-{model-type}-{generation}-{date}` (e.g., `claude-sonnet-4-20250514`, NOT `claude-4-sonnet-20250514`)

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-09-18T16:06:37.474Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/ccusage/CLAUDE.md:0-0
Timestamp: 2025-09-18T16:06:37.474Z
Learning: Applies to apps/ccusage/src/**/*.ts : Do not use console.log; use the logger utilities from `src/logger.ts` instead

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-11-25T14:42:34.734Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-11-25T14:42:34.734Z
Learning: Applies to **/*.{ts,tsx} : Create mock data using `fs-fixture` with `createFixture()` for Claude data directory simulation in tests

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-09-17T18:29:15.764Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/mcp/CLAUDE.md:0-0
Timestamp: 2025-09-17T18:29:15.764Z
Learning: Applies to apps/mcp/**/*.{test,spec}.ts : Use `fs-fixture` for mock data in tests of MCP server functionality

Applied to files:

• apps/ccusage/src/data-loader.ts

📚 Learning: 2025-09-18T16:07:16.293Z

Learnt from: CR
Repo: ryoppippi/ccusage PR: 0
File: apps/codex/CLAUDE.md:0-0
Timestamp: 2025-09-18T16:07:16.293Z
Learning: Tests should use fs-fixture with using to ensure cleanup

Applied to files:

• apps/ccusage/src/data-loader.ts

🔇 Additional comments (4)

apps/ccusage/src/data-loader.ts (4)

148-160: LGTM! Well-designed helper function.

The implementation correctly extracts the project name from file paths with proper cross-platform path handling and defensive checks for malformed paths. The fallback to 'unknown' ensures graceful degradation.

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2627-2649: Excellent regression test for issue #560.

This test explicitly validates that project directories starting with hyphens (e.g., -home-claude-user) are correctly handled, ensuring the session ID is extracted from the filename rather than being confused with directory names.

---

2609-2624: Test fixtures consistently updated to new structure.

All test fixtures have been properly updated to reflect the new file-naming convention where:

• Session IDs are derived from JSONL filenames (e.g., session123.jsonl → sessionId 'session123')
• Files are directly under project directories (project1/session1.jsonl)
• The flat structure aligns with the new extraction logic

The updates are consistent across daily usage tests, session tests, and deduplication tests.

Also applies to: 2682-2698, 2726-2735, 2769-2830, 2864-2879, 2913-2928, 3131-3132, 4456-4479

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940-944: Session ID extraction from JSONL filename is correct.

The change at line 942 properly extracts sessionId using path.basename(file, '.jsonl'), which aligns with the expected file naming convention {sessionId}.jsonl used throughout the codebase. The glob pattern at line 1099 and test fixtures consistently demonstrate JSONL files are named directly with session IDs under project directories. The extractProjectFromPath helper correctly extracts the project name from the directory structure.

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