chore(database): set null value when field is unique and value is empty string (#3997)

* chore(database): set null value when field is unique and value is empty string

* fix: build

packages/core/database/src/__tests__/unique.test.ts

@@ -0,0 +1,114 @@
+import { Database, mockDatabase } from '@nocobase/database';
+
+describe('unique field', () => {
+  let db: Database;
+
+  beforeEach(async () => {
+    db = mockDatabase({
+      logging: console.log,
+    });
+
+    await db.clean({ drop: true });
+  });
+
+  afterEach(async () => {
+    await db.close();
+  });
+
+  it('should not transform empty string to null when field is not unique', async () => {
+    const User = db.collection({
+      name: 'users',
+      fields: [
+        {
+          type: 'string',
+          name: 'name',
+        },
+      ],
+    });
+
+    await db.sync();
+
+    await User.repository.create({
+      values: [
+        {},
+        {
+          name: '',
+        },
+        {
+          name: 'user3',
+        },
+      ],
+    });
+
+    const u3 = await User.repository.findOne({
+      filter: {
+        name: 'user3',
+      },
+    });
+
+    await User.repository.update({
+      filter: {
+        id: u3.id,
+      },
+      values: {
+        name: '',
+      },
+    });
+
+    await u3.reload();
+    expect(u3.get('name')).toBe('');
+  });
+
+  it('should transform empty string to null when field is unique', async () => {
+    const User = db.collection({
+      name: 'users',
+      fields: [
+        {
+          type: 'string',
+          name: 'name',
+          unique: true,
+        },
+      ],
+    });
+
+    await db.sync();
+
+    await User.repository.create({
+      values: [
+        {},
+        {
+          name: '',
+        },
+        {
+          name: 'user3',
+        },
+      ],
+    });
+
+    const u3 = await User.repository.findOne({
+      filter: {
+        name: 'user3',
+      },
+    });
+
+    let error;
+
+    try {
+      await User.repository.update({
+        filter: {
+          id: u3.id,
+        },
+        values: {
+          name: '',
+        },
+      });
+    } catch (e) {
+      error = e;
+    }
+
+    expect(error).toBeUndefined();
+
+    await u3.reload();
+    expect(u3.get('name')).toBe(null);
+  });
+});

packages/core/database/src/database.ts

@@ -406,6 +406,17 @@ export class Database extends EventEmitter implements AsyncEmitter {
       instance?.toChangedWithAssociations?.();
     });
 
+    this.on('beforeValidate', async (instance) => {
+      for (const [key, attribute] of Object.entries(instance.constructor.rawAttributes)) {
+        // @ts-ignore
+        if (attribute.unique && instance.changed(key)) {
+          if (instance.get(key) === '') {
+            instance.set(key, null);
+          }
+        }
+      }
+    });
+
     this.on('afterUpdate', async (instance) => {
       instance?.toChangedWithAssociations?.();
     });