@kristijorgji/code-analysis

Repository code-analysis CLI (kj-analyze) for TypeScript/JavaScript codebases — starting with test-mock duplication detection, with room to grow into more analyzers.

Published from the js-devkit monorepo via npm Trusted Publishing (OIDC).

Install

npm install --save-dev @kristijorgji/code-analysis
# or
pnpm add -D @kristijorgji/code-analysis

Usage

npx kj-analyze test-mocks

This scans your test files for vi.mock(...) / jest.mock(...) calls, groups occurrences of the same mocked module across files, and flags groups whose inline factories are identical or near-duplicate — good candidates for extracting into a shared mock helper. A markdown report is written to reports/test-mock-usage/report.md by default.

Synopsis

kj-analyze <command> [options]

Commands:
  test-mocks   Find near-duplicate vi.mock/jest.mock factories

Options for test-mocks:
  --root <path>
  --scan <path>          (repeatable)
  --out <path>
  --min-occurrences <n>
  --min-lines <n>
  --similarity <0-1>
  --ignore <dirname>     (repeatable, appends to defaults)
  --help

Flags

| Flag | Description | Default | | ---- | ----------- | ------- | | --root <path> | Repository root to analyze. | process.cwd() | | --scan <path> | A path (relative to --root) to scan for test files. Repeatable. | Auto-detected (see below), else src | | --out <path> | Where to write the markdown report (relative to --root). | reports/test-mock-usage/report.md | | --min-occurrences <n> | Minimum number of non-delegating occurrences of a mocked module required to report it. | 2 | | --min-lines <n> | Minimum number of lines a mock(...) call must span to be considered. | 8 | | --similarity <0-1> | Jaccard similarity threshold above which two factories are considered near-duplicate. | 0.8 | | --ignore <dirname> | A directory name to skip while walking. Repeatable; appends to the defaults. | node_modules, dist, coverage | | --help | Print usage and exit. | |

When --scan is omitted and no config file specifies scanPaths, kj-analyze looks for a pnpm-workspace.yaml at the repo root. If it declares workspace packages, it scans for existing apps/*/src and packages/*/src directories. Otherwise it falls back to src if present, or scans nothing.

Environment variables

Flags win over environment variables, which win over the config file, which wins over built-in defaults:

| Variable | Maps to | | -------- | ------- | | MIN_OCCURRENCES | --min-occurrences | | MIN_LINES | --min-lines | | SIMILARITY_THRESHOLD | --similarity |

Config file

Drop a code-analysis.config.json at your repo root to set defaults without passing flags every time:

{
  "scanPaths": ["src"],
  "minOccurrences": 2,
  "minLines": 8,
  "similarityThreshold": 0.8,
  "out": "reports/test-mock-usage/report.md",
  "ignoreDirectories": ["node_modules", "dist", "coverage", "e2e"],
  "pathAliases": {
    "~/": "src/"
  },
  "delegatePatterns": [
    "\\bcreate[A-Z]\\w*Mock\\w*\\s*\\(",
    "\\buseSharedMock\\("
  ]
}

| Key | Type | Description | | --- | ---- | ----------- | | root | string | Repository root override. | | scanPaths | string[] | Paths (relative to root) to scan for *.test.ts(x) / *.spec.ts(x) files. | | minOccurrences | number | Minimum non-delegating occurrences to report a group. | | minLines | number | Minimum lines per mock(...) call to be considered. | | similarityThreshold | number | Jaccard similarity threshold for "near-duplicate". | | out | string | Report output path, relative to root. | | ignoreDirectories | string[] | Directory names to skip while walking (replaces the built-in defaults; use --ignore to append instead). | | pathAliases | Record<string, string> | Extra prefix -> target path aliases, used as a fallback when a scan root has no tsconfig paths. | | delegatePatterns | string[] | Extra regex source strings identifying factories that delegate to a shared mock helper. |

Precedence (highest to lowest): CLI flags > environment variables > config file > built-in defaults.

Programmatic API

import { analyzeTestMocks, formatReport } from '@kristijorgji/code-analysis';

const result = analyzeTestMocks({
    repoRoot: process.cwd(),
    scanPaths: ['src'],
    minOccurrences: 2,
    minLines: 8,
    similarityThreshold: 0.8,
});

const report = formatReport(result, {
    repoRoot: process.cwd(),
    minOccurrences: 2,
    minLines: 8,
});

console.log(report);

Other exports include resolveMockModuleKey, factoryDelegatesToHelper, factoryJaccardSimilarity, hashFactoryBody, tokenizeFactory, jaccardSimilarity, listTestFiles, detectScanPaths, loadConfig/loadConfigFile, resolveConfig/resolveTestMocksConfig, and the underlying path-alias and directory-walking helpers — see src/index.ts for the full surface.

Example report (trimmed)

# Test mock usage report

Scanned **42** test files.
Thresholds: >= **2** non-delegating occurrences, >= **8** lines per mock, near-duplicate >= **80%** similarity.

## expo-notifications

- Kind: package
- Status: **near-duplicate (max 92%)**
- Occurrences: 3 (3 non-delegating)
- Max lines: 6
- Closest pair (92%): `src/screens/a/A.test.ts:4` ↔ `src/screens/b/B.test.ts:4`

| File | Line | Lines | Delegates | Factory hash |
| ---- | ---- | ----- | --------- | ------------ |
| `src/screens/a/A.test.ts` | 4 | 6 | no | 3f9a1c2b9d0e |
| `src/screens/b/B.test.ts` | 4 | 6 | no | 7b2e0a44f1aa |
| `src/screens/c/C.test.ts` | 9 | 6 | no | 7b2e0a44f1aa |

## Already using shared mock helpers

These module groups have fewer than the required non-delegating inline mocks.

### react-i18next

- Kind: package
- Total occurrences: 5
- Delegating to shared helper: 5

| File | Line | Lines | Delegates |
| ---- | ---- | ----- | --------- |
| `src/hooks/useFoo.test.ts` | 3 | 1 | yes |

License

MIT © kristijorgji