Throws error with a more helpful message if a provider object is pass…

…ed to `keep` or `mock`.

libs/ng-mocks/src/lib/mock-builder/promise/init-ng-modules.ts

@@ -151,12 +151,26 @@ export default ({ configDefault, keepDef, mockDef, replaceDef }: BuilderData, de
       continue;
     }
 
-    const errorMessage = [
-      `MockBuilder has found a missing dependency: ${funcGetName(def)}.`,
-      'It means no module provides it.',
-      'Please, use the "export" flag if you want to add it explicitly.',
-      'https://ng-mocks.sudo.eu/api/MockBuilder#export-flag',
-    ].join(' ');
+    const depName = funcGetName(def);
+    const errorMessages = ['Error:'];
+    const defStr = ngMocksUniverse.getResolution(def);
+
+    if (depName === 'Object') {
+      errorMessages.push(
+        `A provider object has been incorrectly passed to the`,
+        `MockerBuilder ${defStr}() method. Did you mean to use`,
+        `MockerBuilder.provide()?`,
+      );
+    } else {
+      errorMessages.push(
+        `MockBuilder has found a missing dependency: ${depName}.`,
+        'It means no module provides it.',
+        'Please, use the "export" flag if you want to add it explicitly.',
+        'https://ng-mocks.sudo.eu/api/MockBuilder#export-flag',
+      );
+    }
+
+    const errorMessage = errorMessages.join(' ');
 
     if (globalFlags.onMockBuilderMissingDependency === 'warn') {
       console.warn(errorMessage);

tests/issue-10020/errors.spec.ts

@@ -0,0 +1,108 @@
+import { Component, Injectable, NgModule } from '@angular/core';
+
+import { MockBuilder } from 'ng-mocks';
+
+@Injectable()
+class RootService {}
+
+@Injectable()
+class TargetService {
+  someAttribute = '';
+  constructor(public readonly root: RootService) {
+    this.someAttribute = 'some value';
+  }
+}
+
+@Component({
+  selector: 'target-10020-errors',
+  template: 'target',
+})
+class TargetComponent {
+  constructor(
+    public readonly target: TargetService,
+    public readonly root: RootService,
+  ) {}
+}
+
+@NgModule({
+  declarations: [TargetComponent],
+  providers: [TargetService],
+})
+class TargetModule {}
+
+class MockProviderClass {
+  someAttribute = 'mock class value';
+}
+
+const mockProviderValue = {
+  provide: TargetService,
+  useValue: { someAttribute: 'mock value' },
+};
+const mockProviderClass = {
+  provide: TargetService,
+  useClass: MockProviderClass,
+};
+const expectedMessagePattern =
+  /A provider object has been incorrectly passed to the MockerBuilder (keep|mock)\(\) method\. Did you mean to use MockerBuilder\.provide\(\)\?/;
+
+describe('issue-10020:errors', () => {
+  describe('strict', () => {
+    describe('.keep', () => {
+      it('throws on using provider value mock with keep', () => {
+        const builder = MockBuilder(
+          TargetComponent,
+          TargetModule,
+        ).keep(mockProviderValue);
+        expect(() => builder.build()).toThrowError(
+          expectedMessagePattern,
+        );
+      });
+
+      it('throws on using provider class mock with keep', () => {
+        const builder = MockBuilder(
+          TargetComponent,
+          TargetModule,
+        ).keep(mockProviderClass);
+        expect(() => builder.build()).toThrowError(
+          expectedMessagePattern,
+        );
+      });
+
+      it('throws on using provider value mock with mock', () => {
+        const builder = MockBuilder(
+          TargetComponent,
+          TargetModule,
+        ).mock(mockProviderValue);
+        expect(() => builder.build()).toThrowError(
+          expectedMessagePattern,
+        );
+      });
+
+      it('throws on using provider class mock with mock', () => {
+        const builder = MockBuilder(
+          TargetComponent,
+          TargetModule,
+        ).mock(mockProviderClass);
+        expect(() => builder.build()).toThrowError(
+          expectedMessagePattern,
+        );
+      });
+
+      it('succeeds on using provider value mock with provide', () => {
+        const builder = MockBuilder(
+          TargetComponent,
+          TargetModule,
+        ).provide(mockProviderValue);
+        expect(() => builder.build()).not.toThrow();
+      });
+
+      it('succeeds on using provider class mock with provide', () => {
+        const builder = MockBuilder(
+          TargetComponent,
+          TargetModule,
+        ).provide(mockProviderClass);
+        expect(() => builder.build()).not.toThrow();
+      });
+    });
+  });
+});