fix: fix min/maxProperties in Ajv validation

Author: mrnagydavid

packages/nodejs-lib/src/validation/ajv/ajv.validations.test.ts

@@ -2642,7 +2642,15 @@ describe('object', () => {
         expect(err, _stringify(value)).toBeNull()
       })
 
-      const invalidCases: any[] = [{ foo: 'foo' }, {}, 0, 'abcd', true, []]
+      const invalidCases: any[] = [
+        { foo: 'foo' },
+        {},
+        0,
+        'abcd',
+        true,
+        [],
+        { abc: 'abc', def: 'def' },
+      ]
       invalidCases.forEach(value => {
         const [err] = ajvSchema.getValidationResult(value)
         expect(err, _stringify(value)).not.toBeNull()
@@ -2861,6 +2869,33 @@ describe('object', () => {
         'The schema must be type checked against a type or interface, using the `.isOfType()` helper in `j`.',
       )
     })
+
+    describe('minProperties', () => {
+      test('should work for withEnumKeys as well', () => {
+        enum E {
+          A = 'a',
+          B = 'b',
+        }
+        const schema = j.object
+          .withEnumKeys(E, j.number().optional())
+          .minProperties(1)
+          .isOfType<Record<E, number | undefined>>()
+        const ajvSchema = AjvSchema.create(schema)
+
+        const validCases: any[] = [{ a: 1 }, { a: 1, b: 2 }]
+        for (const data of validCases) {
+          const [err, result] = ajvSchema.getValidationResult(data)
+          expect(err, _stringify(data)).toBeNull()
+          expect(result, _stringify(data)).toEqual(data)
+        }
+
+        const invalidCases: any[] = [{}, { a: '1' }, { c: 1 }]
+        for (const data of invalidCases) {
+          const [err] = ajvSchema.getValidationResult(data)
+          expect(err, _stringify(data)).not.toBeNull()
+        }
+      })
+    })
   })
 
   describe('.stringMap', () => {

packages/nodejs-lib/src/validation/ajv/getAjv.ts

@@ -478,6 +478,26 @@ export function createAjv(opt?: Options): Ajv2020 {
     },
   })
 
+  // This and `maxProperties2` are added because Ajv validates the `min/maxProperties` before validating the properties.
+  // So, in case of `minProperties(1)` and `{ foo: 'bar' }` Ajv will let it pass, even
+  // if the property validation would strip `foo` from the data.
+  // And Ajv would return `{}` as a successful validation.
+  // Since the keyword validation runs after JSON Schema validation,
+  // here we can make sure the number of properties are right ex-post property validation.
+  // It's named with the `2` suffix, because `minProperties` is reserved.
+  // And `maxProperties` does not suffer from this error due to the nature of how maximum works.
+  ajv.addKeyword({
+    keyword: 'minProperties2',
+    type: 'object',
+    modifying: false,
+    errors: true,
+    schemaType: 'number',
+    validate: function validate(minProperties: number, data: AnyObject, _schema, _ctx) {
+      if (typeof data !== 'object') return true
+      return Object.getOwnPropertyNames(data).length >= minProperties
+    },
+  })
+
   return ajv
 }
 

packages/nodejs-lib/src/validation/ajv/jsonSchemaBuilder.ts

@@ -920,7 +920,7 @@ export class JsonSchemaObjectBuilder<
   }
 
   minProperties(minProperties: number): this {
-    return this.cloneAndUpdateSchema({ minProperties })
+    return this.cloneAndUpdateSchema({ minProperties, minProperties2: minProperties })
   }
 
   maxProperties(maxProperties: number): this {
@@ -1239,6 +1239,7 @@ export interface JsonSchema<IN = unknown, OUT = IN> {
   errorMessages?: StringMap<string>
   optionalValues?: (string | number | boolean)[]
   keySchema?: JsonSchema
+  minProperties2?: number
 }
 
 function object(props: AnyObject): never