feat: add toEJSON API to element

Author: gagik

packages/hadron-document/src/element.ts

@@ -11,8 +11,13 @@ import Events from './element-events';
 import type Document from './document';
 import type { TypeCastTypes } from 'hadron-type-checker';
 import type { Binary, ObjectId } from 'bson';
-import type { BSONArray, BSONObject, BSONValue } from './utils';
-import { getDefaultValueForType } from './utils';
+import type {
+  BSONArray,
+  BSONObject,
+  BSONValue,
+  HadronEJSONOptions,
+} from './utils';
+import { getDefaultValueForType, objectToIdiomaticEJSON } from './utils';
 import { DocumentEvents, ElementEvents } from '.';
 
 export const DATE_FORMAT = 'YYYY-MM-DD HH:mm:ss.SSS';
@@ -292,6 +297,22 @@ export class Element extends EventEmitter {
     return this.value;
   }
 
+  /**
+   * Generate the Extended JSON string representation of this element.
+   *
+   * @returns The Extended JSON string.
+   */
+  toEJSON(
+    source: 'original' | 'current' = 'current',
+    options: HadronEJSONOptions = {}
+  ): string {
+    const generated =
+      source === 'original'
+        ? this.generateOriginalObject()
+        : this.generateObject();
+    return objectToIdiomaticEJSON(generated, options);
+  }
+
   /**
    * Insert an element after the provided element. If this element is an array,
    * then ignore the key specified by the caller and use the correct index.

packages/hadron-document/test/element.test.ts

@@ -3038,4 +3038,82 @@ describe('Element', function () {
       });
     }
   );
+
+  describe('#toEJSON', function () {
+    it('handles null values', function () {
+      const element = new Element('test', {
+        a: 1,
+        b: { foo: 2 },
+        null_val: null,
+      });
+      expect(element.toEJSON('current', { indent: undefined })).to.equal(
+        '{"a":1,"b":{"foo":2},"null_val":null}'
+      );
+    });
+
+    it('serializes Int32/Double as relaxed but not Int64', function () {
+      const element = new Element('test', {
+        a: 1,
+        b: 1.5,
+        c: Long.fromNumber(2),
+      });
+      expect(element.toEJSON('current', { indent: undefined })).to.equal(
+        '{"a":1,"b":1.5,"c":{"$numberLong":"2"}}'
+      );
+    });
+
+    it('serializes Date as relaxed, but not dates before 1970 and after 9999', function () {
+      const element = new Element('test', {
+        epoch: new Date(0),
+        negative: new Date(-1),
+        y10k: new Date(253402300800000),
+      });
+      expect(element.toEJSON('current', { indent: undefined })).to.equal(
+        '{"epoch":{"$date":"1970-01-01T00:00:00.000Z"},"negative":{"$date":{"$numberLong":"-1"}},"y10k":{"$date":{"$numberLong":"253402300800000"}}}'
+      );
+    });
+
+    it('optionally serializes the current or the original element', function () {
+      const element = new Element('test', {
+        a: 1,
+        b: 1.5,
+        c: Long.fromNumber(2),
+      });
+      element.get('a')?.edit(new Int32(2));
+      expect(element.toEJSON('current', { indent: undefined })).to.equal(
+        '{"a":2,"b":1.5,"c":{"$numberLong":"2"}}'
+      );
+      expect(element.toEJSON('original', { indent: undefined })).to.equal(
+        '{"a":1,"b":1.5,"c":{"$numberLong":"2"}}'
+      );
+    });
+
+    it('allows specifying JSON indent', function () {
+      const element = new Element('test', { a: 1 });
+      expect(element.toEJSON('current', { indent: '>' })).to.equal(
+        '{\n>"a": 1\n}'
+      );
+    });
+
+    it('handles oddball floating point values', function () {
+      const element = new Element('test', {
+        negzero: new Double(-0),
+        int: new Int32(1),
+        inf: Infinity,
+        ninf: -Infinity,
+        nan: NaN,
+      });
+      expect(element.toEJSON('current', { indent: undefined })).to.equal(
+        '{' +
+          [
+            '"negzero":{"$numberDouble":"-0.0"},',
+            '"int":1,',
+            '"inf":{"$numberDouble":"Infinity"},',
+            '"ninf":{"$numberDouble":"-Infinity"},',
+            '"nan":{"$numberDouble":"NaN"}',
+          ].join('') +
+          '}'
+      );
+    });
+  });
 });