feat(@ngtools/json-schema): add support for enums.

Close #4082

Author: hansl

packages/@ngtools/json-schema/src/schema-tree.spec.ts

@@ -4,31 +4,54 @@ import {join} from 'path';
 import {RootSchemaTreeNode} from './schema-tree';
 
 
-describe('SchemaTreeNode', () => {
+describe('@ngtools/json-schema', () => {
 
-});
+  describe('OneOfSchemaTreeNode', () => {
+    const schemaJsonFilePath = join(__dirname, '../tests/schema1.json');
+    const schemaJson = JSON.parse(readFileSync(schemaJsonFilePath, 'utf-8'));
+    const valueJsonFilePath = join(__dirname, '../tests/value1-1.json');
+    const valueJson = JSON.parse(readFileSync(valueJsonFilePath, 'utf-8'));
 
 
-describe('OneOfSchemaTreeNode', () => {
-  const schemaJsonFilePath = join(__dirname, '../tests/schema1.json');
-  const schemaJson = JSON.parse(readFileSync(schemaJsonFilePath, 'utf-8'));
-  const valueJsonFilePath = join(__dirname, '../tests/value1-1.json');
-  const valueJson = JSON.parse(readFileSync(valueJsonFilePath, 'utf-8'));
+    it('works', () => {
+      const proto: any = Object.create(null);
+      new RootSchemaTreeNode(proto, {
+        value: valueJson,
+        schema: schemaJson
+      });
 
+      expect(proto.oneOfKey2 instanceof Array).toBe(true);
+      expect(proto.oneOfKey2.length).toBe(2);
 
-  it('works', () => {
-    const proto: any = Object.create(null);
-    new RootSchemaTreeNode(proto, {
-      value: valueJson,
-      schema: schemaJson
+      // Set it to a string, which is valid.
+      proto.oneOfKey2 = 'hello';
+      expect(proto.oneOfKey2 instanceof Array).toBe(false);
     });
+  });
+
+
+  describe('EnumSchemaTreeNode', () => {
+    const schemaJsonFilePath = join(__dirname, '../tests/schema2.json');
+    const schemaJson = JSON.parse(readFileSync(schemaJsonFilePath, 'utf-8'));
+    const valueJsonFilePath = join(__dirname, '../tests/value2-1.json');
+    const valueJson = JSON.parse(readFileSync(valueJsonFilePath, 'utf-8'));
+
 
-    expect(proto.oneOfKey2 instanceof Array).toBe(true);
-    expect(proto.oneOfKey2.length).toBe(2);
+    it('works', () => {
+      const proto: any = Object.create(null);
+      new RootSchemaTreeNode(proto, {
+        value: valueJson,
+        schema: schemaJson
+      });
 
-    // Set it to a string, which is valid.
-    proto.oneOfKey2 = 'hello';
-    expect(proto.oneOfKey2 instanceof Array).toBe(false);
+      expect(proto.a instanceof Array).toBe(true);
+      expect(proto.a).toEqual([null, 'v1', null, 'v3']);
+
+      // Set it to a string, which is valid.
+      proto.a[0] = 'v2';
+      proto.a[1] = 'INVALID';
+      expect(proto.a).toEqual(['v2', null, null, 'v3']);
+    });
   });
-});
 
+});

packages/@ngtools/json-schema/src/schema-tree.ts

@@ -4,6 +4,7 @@ import {SchemaNode, TypeScriptType} from './node';
 
 
 export class InvalidSchema extends JsonSchemaErrorBase {}
+export class InvalidValueError extends JsonSchemaErrorBase {}
 export class MissingImplementationError extends JsonSchemaErrorBase {}
 export class SettingReadOnlyPropertyError extends JsonSchemaErrorBase {}
 
@@ -151,8 +152,9 @@ export abstract class NonLeafSchemaTreeNode<T> extends SchemaTreeNode<T> {
   // Helper function to create a child based on its schema.
   protected _createChildProperty<T>(name: string, value: T, forward: SchemaTreeNode<T>,
                                     schema: Schema, define = true): SchemaTreeNode<T> {
-
-    let type: string = schema['oneOf'] ? 'oneOf' : schema['type'];
+    const type: string =
+      ('oneOf' in schema) ? 'oneOf' :
+      ('enum' in schema) ? 'enum' : schema['type'];
     let Klass: { new (arg: TreeNodeConstructorArgument<any>): SchemaTreeNode<any> } = null;
 
     switch (type) {
@@ -163,6 +165,7 @@ export abstract class NonLeafSchemaTreeNode<T> extends SchemaTreeNode<T> {
       case 'number': Klass = NumberSchemaTreeNode; break;
       case 'integer': Klass = IntegerSchemaTreeNode; break;
 
+      case 'enum': Klass = EnumSchemaTreeNode; break;
       case 'oneOf': Klass = OneOfSchemaTreeNode; break;
 
       default:
@@ -327,7 +330,8 @@ export class ArraySchemaTreeNode extends NonLeafSchemaTreeNode<Array<any>> {
     this._set(metaData.value, true, false);
 
     // Keep the item's schema as a schema node. This is important to keep type information.
-    this._itemPrototype = this._createChildProperty('', null, null, metaData.schema['items']);
+    this._itemPrototype = this._createChildProperty(
+      '', null, null, metaData.schema['items'], false);
   }
 
   _set(value: any, init: boolean, force: boolean) {
@@ -397,7 +401,7 @@ export abstract class LeafSchemaTreeNode<T> extends SchemaTreeNode<T> {
     super(metaData);
     this._defined = !(metaData.value === undefined || metaData.value === null);
     if ('default' in metaData.schema) {
-      this._default = metaData.schema['default'];
+      this._default = this.convert(metaData.schema['default']);
     }
   }
 
@@ -415,8 +419,15 @@ export abstract class LeafSchemaTreeNode<T> extends SchemaTreeNode<T> {
       throw new SettingReadOnlyPropertyError();
     }
 
+    let convertedValue: T | null = this.convert(v);
+    if (convertedValue === null || convertedValue === undefined) {
+      if (this.required) {
+        throw new InvalidValueError(`Invalid value "${v}" on a required field.`);
+      }
+    }
+
     this.dirty = true;
-    this._value = this.convert(v);
+    this._value = convertedValue;
   }
 
   destroy() {
@@ -448,6 +459,38 @@ class StringSchemaTreeNode extends LeafSchemaTreeNode<string> {
 }
 
 
+class EnumSchemaTreeNode extends StringSchemaTreeNode {
+  private _enumValues: string[];
+
+  constructor(metaData: TreeNodeConstructorArgument<string>) {
+    super(metaData);
+
+    if (!Array.isArray(metaData.schema['enum'])) {
+      throw new InvalidSchema();
+    }
+    this._enumValues = [].concat(metaData.schema['enum']);
+    this.set(metaData.value, true);
+  }
+
+  protected _isInEnum(value: string) {
+    return this._enumValues.some(v => v === value);
+  }
+
+  isCompatible(v: any) {
+    return (typeof v == 'string' || v instanceof String) && this._isInEnum('' + v);
+  }
+  convert(v: any) {
+    if (v === undefined) {
+      return undefined;
+    }
+    if (v === null || !this._isInEnum('' + v)) {
+      return null;
+    }
+    return '' + v;
+  }
+}
+
+
 class BooleanSchemaTreeNode extends LeafSchemaTreeNode<boolean> {
   serialize(serializer: Serializer) { serializer.outputBoolean(this); }
 

packages/@ngtools/json-schema/tests/schema2.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "id": "JsonSchema",
+  "type": "object",
+  "properties": {
+    "a": {
+      "type": "array",
+      "items": {
+        "enum": [ "v1", "v2", "v3" ]
+      }
+    }
+  }
+}

packages/@ngtools/json-schema/tests/value2-1.json

@@ -0,0 +1,8 @@
+{
+  "a": [
+    "INVALID",
+    "v1",
+    "INVALID",
+    "v3"
+  ]
+}