Add type check

.github/workflows/type-check.yml

@@ -0,0 +1,23 @@
+name: Type Check
+
+on:
+  pull_request:
+    branches:
+      - main
+jobs:
+  typecheck:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '24'
+
+      - name: Install dependencies
+        run: npm i
+
+      - name: Run type check
+        run: npm run check:types

lib/compile/index.js

@@ -184,4 +184,5 @@ function _servicePath(csdl, csn, protocols) {
 
     return paths;
   }
+  return {}
 }

lib/compile/types.d.ts

@@ -0,0 +1,50 @@
+type StringSchema = {
+    type: 'string'
+    format?: 'base64url' | 'uuid' | 'time' | 'date' | 'date-time' | 'duration'
+    maxLength?: number
+    example?: string
+    pattern?: string
+}
+
+type NumberSchema = {
+    type: 'number' | 'integer'
+    format?: 'float' | 'double' | 'decimal' | 'uint8' | 'int8' | 'int16' | 'int32' | 'int64'
+    multipleOf?: number
+    example?: number,
+    minimum?: number
+    maximum?: number
+    exclusiveMinimum?: boolean
+    exclusiveMaximum?: boolean
+}
+
+type BooleanSchema = {
+    type: 'boolean'
+}
+
+type ArraySchema = {
+    type: 'array',
+    items: Schema
+}
+
+type Meta = {
+    nullable?: boolean
+    default?: unknown
+    example?: string | number,
+    description?: string
+    '$ref'?: unknown
+}
+
+type SingleSchema = (StringSchema | NumberSchema | BooleanSchema | ArraySchema) & Meta
+
+type AnyOf = { anyOf: Schema[] } & Meta
+type AllOf = { allOf: Schema[] } & Meta
+type MultiSchema = AnyOf | AllOf
+
+export type Schema = (SingleSchema | MultiSchema)
+
+
+
+export type TargetRestrictions = {
+    Countable?: boolean
+    Expandable?: boolean
+}

package.json

@@ -22,7 +22,8 @@
   ],
   "scripts": {
     "test": "npx jest --silent",
-    "lint": "npx eslint ."
+    "lint": "npx eslint .",
+    "check:types": "npx tsc --noEmit"
   },
   "dependencies": {
     "pluralize": "^8.0.0"
@@ -31,7 +32,9 @@
     "@sap/cds": ">=7.6"
   },
   "devDependencies": {
+    "@types/node": "^24.3.0",
+    "eslint": "^8.56.0",
     "jest": ">=29",
-    "eslint": "^8.56.0"
+    "typescript": "^5.9.2"
   }
 }

tsconfig.json

@@ -0,0 +1,31 @@
+{
+  // Visit https://aka.ms/tsconfig to read more about this file
+  "compilerOptions": {
+    "module": "nodenext",
+    "target": "esnext",
+    "lib": ["esnext"],
+    "types": ["node"],
+    "allowJs": true,
+    "checkJs": true,
+    "noUncheckedIndexedAccess": false,
+    "exactOptionalPropertyTypes": true,
+    "noImplicitOverride": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "noPropertyAccessFromIndexSignature": true,
+    "strict": true,
+    "jsx": "react-jsx",
+    "verbatimModuleSyntax": true,
+    "isolatedModules": true,
+    "noUncheckedSideEffectImports": true,
+    "moduleDetection": "force",
+    "skipLibCheck": true,
+    // enable after first round
+    "noImplicitReturns": false,
+    "noImplicitAny": false,
+  },
+  "exclude": [
+    "**/*.test.js"
+  ]
+}