Adopt Fallow as a PR quality gate (#768)

* Adopt Fallow as a PR quality gate

Model Storybook MDX and the Rsbuild compatibility config as runtime entries. Keep Rsbuild and Size Limit packages as dependency exceptions because their CLI/config loading is not visible to static imports, and keep verified Storybook package subpaths as resolver exceptions. Mark the published reset helper as public API and limit the Storybook-only CRAP override to 60 because interactive demos are intentionally excluded from unit coverage while structural thresholds remain unchanged.

* Tighten Fallow policy exceptions

Remove the duplication threshold because zero disables Fallow's percentage limit. Scope Storybook CRAP exceptions to the four exact uncovered functions with the smallest passing ceilings, and inline the one-use options serializer so the health cleanup does not add indirection merely to move complexity between functions.

* Close remaining Fallow gate gaps

Treat production imports from dev dependencies as errors and inline the one-use Storybook wrapper. Keep the UseOnInViewRender exception function-scoped at the smallest passing CRAP ceiling because Storybook demos are intentionally outside unit coverage.

Author: thebuilder

.fallowrc.json

@@ -0,0 +1,59 @@
+{
+  "$schema": "https://raw.githubusercontent.com/fallow-rs/fallow/main/schema.json",
+  "entry": [
+    "fixtures/react-compat/rsbuild.config.mjs",
+    "storybook/stories/**/*.mdx"
+  ],
+  "ignoreDependencies": [
+    "@rsbuild/core",
+    "@rsbuild/plugin-react",
+    "@size-limit/preset-small-lib"
+  ],
+  "ignoreUnresolvedImports": [
+    "storybook/actions",
+    "storybook/manager-api",
+    "storybook/theming"
+  ],
+  "rules": {
+    "unused-files": "error",
+    "unused-exports": "error",
+    "unused-dependencies": "error",
+    "unused-dev-dependencies": "error",
+    "dev-dependencies-in-production": "error",
+    "unresolved-imports": "error",
+    "unlisted-dependencies": "error",
+    "circular-dependencies": "error",
+    "stale-suppressions": "error"
+  },
+  "duplicates": {
+    "minOccurrences": 2
+  },
+  "health": {
+    "maxCyclomatic": 20,
+    "maxCognitive": 15,
+    "maxCrap": 30,
+    "maxUnitSize": 60,
+    "coverage": "coverage/coverage-final.json",
+    "thresholdOverrides": [
+      {
+        "files": ["storybook/stories/elements.tsx"],
+        "functions": ["EntryDetails", "ScrollWrapper"],
+        "maxCrap": 31,
+        "reason": "Interactive Storybook demos are intentionally excluded from unit coverage; retain the default structural complexity limits while allowing these two estimated CRAP scores."
+      },
+      {
+        "files": ["storybook/stories/useInView.story.tsx"],
+        "functions": ["HooksRender"],
+        "maxCrap": 43,
+        "reason": "This interactive Storybook demo is intentionally excluded from unit coverage; retain the default structural complexity limits while allowing its estimated CRAP score."
+      },
+      {
+        "files": ["storybook/stories/useOnInView.story.tsx"],
+        "functions": ["UseOnInViewRender"],
+        "maxCrap": 57,
+        "reason": "This interactive Storybook demo is intentionally excluded from unit coverage; retain the default structural complexity limits while allowing its measured CRAP score of 56."
+      }
+    ],
+    "suggestInlineSuppression": false
+  }
+}

.github/workflows/test.yml

@@ -12,6 +12,8 @@ jobs:
 
     steps:
       - uses: actions/checkout@v7
+        with:
+          fetch-depth: 0
       - run: corepack enable
       - name: Setup Node.js
         uses: actions/setup-node@v6
@@ -28,6 +30,9 @@ jobs:
         run: pnpm vitest --coverage
         env:
           CI: true
+      - name: Fallow audit
+        if: github.event_name == 'pull_request'
+        run: pnpm fallow audit --base "origin/${{ github.base_ref }}"
       - name: Build
         run: pnpm build
 

.gitignore

@@ -20,3 +20,4 @@ storybook-static
 test-utils.js
 test-utils.d.ts
 __screenshots__
+.fallow/

package.json

@@ -135,8 +135,8 @@
     "@vitest/browser-playwright": "^4.0.16",
     "@vitest/coverage-istanbul": "^4.0.16",
     "bumpp": "^10.3.2",
+    "fallow": "3.10.0",
     "lint-staged": "^16.2.7",
-    "microbundle": "^0.15.1",
     "npm-run-all": "^4.1.5",
     "playwright": "^1.57.0",
     "publint": "^0.3.16",