Merge pull request #1473 from vinnymac/feature/support-null-unions

feat(plugin): Update plugin with null union support

lib/plugin/utils/ast-utils.ts

@@ -16,6 +16,8 @@ import {
   CommentRange,
   getLeadingCommentRanges,
   getTrailingCommentRanges,
+  UnionTypeNode,
+  TypeNode,
 } from 'typescript';
 import { isDynamicallyAdded } from './plugin-utils';
 
@@ -70,6 +72,22 @@ export function isEnumLiteral(type: Type) {
   return hasFlag(type, TypeFlags.EnumLiteral) && !type.isUnion();
 }
 
+export function isNull(type: Type) {
+  if (type.isUnion()) {
+    return Boolean(type.types.find((t) => hasFlag(t, TypeFlags.Null)));
+  } else {
+    return hasFlag(type, TypeFlags.Null);
+  }
+}
+
+export function isUndefined(type: Type) {
+  if (type.isUnion()) {
+    return Boolean(type.types.find((t) => hasFlag(t, TypeFlags.Undefined)));
+  } else {
+    return hasFlag(type, TypeFlags.Undefined);
+  }
+}
+
 export function hasFlag(type: Type, flag: TypeFlags) {
   return (type.flags & flag) === flag;
 }
@@ -172,3 +190,10 @@ export function getDescriptionOfNode(
   }
   return description.join('\n');
 }
+
+export function findNullableTypeFromUnion(typeNode: UnionTypeNode, typeChecker: TypeChecker) {
+  return typeNode.types.find(
+    (tNode: TypeNode) =>
+      hasFlag(typeChecker.getTypeAtLocation(tNode), TypeFlags.Null)
+  );
+}

lib/plugin/utils/plugin-utils.ts

@@ -66,7 +66,7 @@ export function getTypeReferenceAsString(
       return Boolean.name;
     }
     if (isEnum(type)) {
-      return getText(type, typeChecker);
+      return text;
     }
     const isEnumMember =
       type.symbol && type.symbol.flags === ts.SymbolFlags.EnumMember;
@@ -76,7 +76,7 @@ export function getTypeReferenceAsString(
       if (!type) {
         return undefined;
       }
-      return getText(type, typeChecker);
+      return text;
     }
     if (
       isAutoGeneratedTypeUnion(type) ||

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

@@ -3,7 +3,7 @@ import * as ts from 'typescript';
 import { HideField } from '../../decorators';
 import { PluginOptions } from '../merge-options';
 import { METADATA_FACTORY_NAME } from '../plugin-constants';
-import { getDescriptionOfNode } from '../utils/ast-utils';
+import { findNullableTypeFromUnion, getDescriptionOfNode, isNull, isUndefined } from '../utils/ast-utils';
 import {
   getDecoratorOrUndefinedByNames,
   getTypeReferenceAsString,
@@ -131,17 +131,18 @@ export class ModelClassVisitor {
     typeChecker: ts.TypeChecker,
     existingProperties: ts.NodeArray<ts.PropertyAssignment> = ts.createNodeArray(),
     hostFilename = '',
-    sourceFile: ts.SourceFile,
-    pluginOptions: PluginOptions,
+    sourceFile?: ts.SourceFile,
+    pluginOptions?: PluginOptions,
   ): ts.ObjectLiteralExpression {
-    const isRequired = !node.questionToken;
+    const type = typeChecker.getTypeAtLocation(node);
+    const isNullable = !!node.questionToken || isNull(type) || isUndefined(type);
 
     const properties = [
       ...existingProperties,
-      !hasPropertyKey('nullable', existingProperties) &&
-        ts.createPropertyAssignment('nullable', ts.createLiteral(!isRequired)),
+      !hasPropertyKey('nullable', existingProperties) && isNullable &&
+        ts.createPropertyAssignment('nullable', ts.createLiteral(isNullable)),
       this.createTypePropertyAssignment(
-        node,
+        node.type,
         typeChecker,
         existingProperties,
         hostFilename,
@@ -160,50 +161,69 @@ export class ModelClassVisitor {
   }
 
   createTypePropertyAssignment(
-    node: ts.PropertyDeclaration | ts.PropertySignature,
+    node: ts.TypeNode,
     typeChecker: ts.TypeChecker,
     existingProperties: ts.NodeArray<ts.PropertyAssignment>,
     hostFilename: string,
-    sourceFile: ts.SourceFile,
-    pluginOptions: PluginOptions,
-  ) {
+    sourceFile?: ts.SourceFile,
+    pluginOptions?: PluginOptions
+  ): ts.PropertyAssignment {
     const key = 'type';
     if (hasPropertyKey(key, existingProperties)) {
       return undefined;
     }
-    const type = typeChecker.getTypeAtLocation(node);
-    if (!type) {
-      return undefined;
-    }
-    if (node.type && ts.isTypeLiteralNode(node.type)) {
-      const propertyAssignments = Array.from(node.type.members || []).map(
-        (member) => {
-          const literalExpr = this.createDecoratorObjectLiteralExpr(
-            member as ts.PropertySignature,
+
+    if (node) {
+      if (ts.isTypeLiteralNode(node)) {
+        const propertyAssignments = Array.from(node.members || []).map(
+          (member) => {
+            const literalExpr = this.createDecoratorObjectLiteralExpr(
+              member as ts.PropertySignature,
+              typeChecker,
+              existingProperties,
+              hostFilename,
+              sourceFile,
+              pluginOptions,
+            );
+            return ts.createPropertyAssignment(
+              ts.createIdentifier(member.name.getText()),
+              literalExpr,
+            );
+          },
+        );
+        return ts.createPropertyAssignment(
+          key,
+          ts.createArrowFunction(
+            undefined,
+            undefined,
+            [],
+            undefined,
+            undefined,
+            ts.createParen(ts.createObjectLiteral(propertyAssignments)),
+          ),
+        );
+      } else if (ts.isUnionTypeNode(node)) {
+        const nullableType = findNullableTypeFromUnion(node, typeChecker);
+        const remainingTypes = node.types.filter(
+          (item) => item !== nullableType
+        );
+
+        if (remainingTypes.length === 1) {
+          return this.createTypePropertyAssignment(
+            remainingTypes[0],
             typeChecker,
             existingProperties,
             hostFilename,
-            sourceFile,
-            pluginOptions,
-          );
-          return ts.createPropertyAssignment(
-            ts.createIdentifier(member.name.getText()),
-            literalExpr,
           );
-        },
-      );
-      return ts.createPropertyAssignment(
-        key,
-        ts.createArrowFunction(
-          undefined,
-          undefined,
-          [],
-          undefined,
-          undefined,
-          ts.createParen(ts.createObjectLiteral(propertyAssignments)),
-        ),
-      );
+        }
+      }
     }
+
+    const type = typeChecker.getTypeAtLocation(node);
+    if (!type) {
+      return undefined;
+    }
+
     let typeReference = getTypeReferenceAsString(type, typeChecker);
     if (!typeReference) {
       return undefined;
@@ -221,6 +241,7 @@ export class ModelClassVisitor {
         importsToAdd.add(importPath.slice(2, importPath.length - 1));
       }
     }
+
     return ts.createPropertyAssignment(
       key,
       ts.createArrowFunction(

tests/plugin/fixtures/create-cat-alt.dto.ts

@@ -65,7 +65,7 @@ export class CreateCatDto2 {
         this.status = Status.ENABLED;
     }
     static _GRAPHQL_METADATA_FACTORY() {
-        return { name: { nullable: false, type: () => String, description: "name description" }, age: { nullable: false, type: () => Number, description: "test on age" }, tags: { nullable: false, type: () => [String] }, status: { nullable: false, type: () => Status }, breed: { nullable: true, type: () => String }, nodes: { nullable: false, type: () => [Object] }, alias: { nullable: false, type: () => Object }, numberAlias: { nullable: false, type: () => Number }, union: { nullable: false, type: () => Object }, intersection: { nullable: false, type: () => Object }, optionalBoolean: { nullable: true, type: () => Boolean }, nested: { nullable: false, type: () => ({ first: { nullable: false, type: () => String }, second: { nullable: false, type: () => Number }, status: { nullable: false, type: () => Status }, tags: { nullable: false, type: () => [String] }, nodes: { nullable: false, type: () => [Object] }, alias: { nullable: false, type: () => Object }, numberAlias: { nullable: false, type: () => Number } }) }, tuple: { nullable: false, type: () => Object } };
+        return { name: { type: () => String, description: "name description" }, age: { type: () => Number, description: "test on age" }, tags: { type: () => [String] }, status: { type: () => Status }, breed: { nullable: true, type: () => String }, nodes: { type: () => [Object] }, alias: { type: () => Object }, numberAlias: { type: () => Number }, union: { type: () => Object }, intersection: { type: () => Object }, optionalBoolean: { nullable: true, type: () => Boolean }, nested: { type: () => ({ first: { type: () => String }, second: { type: () => Number }, status: { type: () => Status }, tags: { type: () => [String] }, nodes: { type: () => [Object] }, alias: { type: () => Object }, numberAlias: { type: () => Number } }) }, tuple: { type: () => Object } };
     }
 }
 `;

tests/plugin/fixtures/create-cat.dto.ts

@@ -45,7 +45,7 @@ export class CreateCatDto {
         this.status = Status.ENABLED;
     }
     static _GRAPHQL_METADATA_FACTORY() {
-        return { name: { nullable: false, type: () => String }, age: { nullable: false, type: () => Number }, tags: { nullable: false, type: () => [String] }, status: { nullable: false, type: () => Status }, status2: { nullable: true, type: () => Status }, statusArr: { nullable: true, type: () => [Status] }, breed: { nullable: true, type: () => String }, nodes: { nullable: false, type: () => [Object] }, date: { nullable: false, type: () => Date } };
+        return { name: { type: () => String }, age: { type: () => Number }, tags: { type: () => [String] }, status: { type: () => Status }, status2: { nullable: true, type: () => Status }, statusArr: { nullable: true, type: () => [Status] }, breed: { nullable: true, type: () => String }, nodes: { type: () => [Object] }, date: { type: () => Date } };
     }
 }
 __decorate([

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

@@ -21,7 +21,7 @@ var CreateCatDtoEs5 = /** @class */ (function () {
         this.obj = constants_1.CONSTANT_OBJECT;
     }
     CreateCatDtoEs5._GRAPHQL_METADATA_FACTORY = function () {
-        return { name: { nullable: false, type: function () { return String; } }, status: { nullable: false, type: function () { return Object; } }, obj: { nullable: false, type: function () { return Object; } } };
+        return { name: { type: function () { return String; } }, status: { type: function () { return Object; } }, obj: { type: function () { return Object; } } };
     };
     return CreateCatDtoEs5;
 }());

tests/plugin/fixtures/nullable.dto.ts

@@ -0,0 +1,34 @@
+export const nullableDtoText = `
+enum Status {
+    ENABLED,
+    DISABLED
+}
+
+export class NullableDto {
+  name: string | null;
+  age: number = 3;
+  tags: string[];
+  status: Status = Status.ENABLED;
+  status2?: Status | null;
+  statusArr?: Status[];
+  readonly breed?: string;
+  nodes: Node[];
+  date: Date | undefined;
+}
+`;
+
+export const nullableDtoTextTranspiled = `var Status;
+(function (Status) {
+    Status[Status["ENABLED"] = 0] = "ENABLED";
+    Status[Status["DISABLED"] = 1] = "DISABLED";
+})(Status || (Status = {}));
+export class NullableDto {
+    constructor() {
+        this.age = 3;
+        this.status = Status.ENABLED;
+    }
+    static _GRAPHQL_METADATA_FACTORY() {
+        return { name: { nullable: true, type: () => String }, age: { type: () => Number }, tags: { type: () => [String] }, status: { type: () => Status }, status2: { nullable: true, type: () => Status }, statusArr: { nullable: true, type: () => [Status] }, breed: { nullable: true, type: () => String }, nodes: { type: () => [Object] }, date: { nullable: true, type: () => Date } };
+    }
+}
+`

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

@@ -12,6 +12,10 @@ import {
   es5CreateCatDtoText,
   es5CreateCatDtoTextTranspiled,
 } from './fixtures/es5-class.dto';
+import {
+  nullableDtoText,
+  nullableDtoTextTranspiled
+} from './fixtures/nullable.dto';
 
 describe('API model properties', () => {
   it('should add the metadata factory when no decorators exist', () => {
@@ -84,4 +88,25 @@ describe('API model properties', () => {
     });
     expect(result.outputText).toEqual(es5CreateCatDtoTextTranspiled);
   });
+
+  it('should support & understand nullable type unions', () => {
+    const options: ts.CompilerOptions = {
+      module: ts.ModuleKind.ESNext,
+      target: ts.ScriptTarget.ESNext,
+      newLine: ts.NewLineKind.LineFeed,
+      noEmitHelpers: true,
+      strict: true
+    };
+    const filename = 'nullable.input.ts';
+    const fakeProgram = ts.createProgram([filename], options);
+
+    const result = ts.transpileModule(nullableDtoText, {
+      compilerOptions: options,
+      fileName: filename,
+      transformers: {
+        before: [before({}, fakeProgram)],
+      },
+    });
+    expect(result.outputText).toEqual(nullableDtoTextTranspiled);
+  });
 });