fix(plugin): add imports when downleveled (transpilation)

lib/plugin/visitors/model-class.visitor.ts

@@ -266,10 +266,7 @@ export class ModelClassVisitor extends AbstractFileVisitor {
     if (ts.isAsExpression(initializer)) {
       initializer = initializer.expression;
     }
-    return ts.createPropertyAssignment(
-      key,
-      ts.createIdentifier(initializer.getText())
-    );
+    return ts.createPropertyAssignment(key, ts.getMutableClone(initializer));
   }
 
   createValidationPropertyAssignments(
@@ -320,12 +317,11 @@ export class ModelClassVisitor extends AbstractFileVisitor {
       return;
     }
     const argument: ts.Expression = head(getDecoratorArguments(decoratorRef));
-    assignments.push(
-      ts.createPropertyAssignment(
-        propertyKey,
-        ts.createIdentifier(argument && argument.getText())
-      )
-    );
+    if (argument) {
+      assignments.push(
+        ts.createPropertyAssignment(propertyKey, ts.getMutableClone(argument))
+      );
+    }
   }
 
   addClassMetadata(

test/plugin/fixtures/es5-class.dto.ts

@@ -0,0 +1,39 @@
+export const es5CreateCatDtoText = `
+import { IsInt, IsString } from 'class-validator';
+import { Status } from './status';
+import { CONSTANT_STRING, CONSTANT_OBJECT, MIN_VAL } from './constants';
+
+export class CreateCatDtoEs5 {
+  name: string = CONSTANT_STRING;
+  status: Status = Status.ENABLED;
+  obj = CONSTANT_OBJECT;
+
+  @Min(MIN_VAL)
+  @Max(10)
+  age: number = 3;
+}
+`;
+
+export const es5CreateCatDtoTextTranspiled = `\"use strict\";
+Object.defineProperty(exports, \"__esModule\", { value: true });
+var openapi = require(\"@nestjs/swagger\");
+var status_1 = require(\"./status\");
+var constants_1 = require(\"./constants\");
+var CreateCatDtoEs5 = /** @class */ (function () {
+    function CreateCatDtoEs5() {
+        this.name = constants_1.CONSTANT_STRING;
+        this.status = status_1.Status.ENABLED;
+        this.obj = constants_1.CONSTANT_OBJECT;
+        this.age = 3;
+    }
+    CreateCatDtoEs5._OPENAPI_METADATA_FACTORY = function () {
+        return { name: { required: true, type: function () { return String; }, default: constants_1.CONSTANT_STRING }, status: { required: true, type: function () { return Object; }, default: status_1.Status.ENABLED }, obj: { required: true, type: function () { return Object; }, default: constants_1.CONSTANT_OBJECT }, age: { required: true, type: function () { return Number; }, default: 3, minimum: constants_1.MIN_VAL, maximum: 10 } };
+    };
+    __decorate([
+        Min(constants_1.MIN_VAL),
+        Max(10)
+    ], CreateCatDtoEs5.prototype, \"age\", void 0);
+    return CreateCatDtoEs5;
+}());
+exports.CreateCatDtoEs5 = CreateCatDtoEs5;
+`;

test/plugin/model-class-visitor.spec.ts

@@ -12,6 +12,10 @@ import {
   createCatDtoText,
   createCatDtoTextTranspiled
 } from './fixtures/create-cat.dto';
+import {
+  es5CreateCatDtoText,
+  es5CreateCatDtoTextTranspiled
+} from './fixtures/es5-class.dto';
 
 describe('API model properties', () => {
   it('should add the metadata factory when no decorators exist', () => {
@@ -70,4 +74,23 @@ describe('API model properties', () => {
     });
     expect(result.outputText).toEqual(createCatDtoTextAlt2Transpiled);
   });
+
+  it('should manage imports statements when code "downleveled"', () => {
+    const options: ts.CompilerOptions = {
+      module: ts.ModuleKind.CommonJS,
+      target: ts.ScriptTarget.ES5,
+      noEmitHelpers: true
+    };
+    const filename = 'es5-class.dto.ts';
+    const fakeProgram = ts.createProgram([filename], options);
+
+    const result = ts.transpileModule(es5CreateCatDtoText, {
+      compilerOptions: options,
+      fileName: filename,
+      transformers: {
+        before: [before({ classValidatorShim: true }, fakeProgram)]
+      }
+    });
+    expect(result.outputText).toEqual(es5CreateCatDtoTextTranspiled);
+  });
 });