feat: Json data type

src/data-type.ts

@@ -41,6 +41,7 @@ import { type CryptoMetadata } from './always-encrypted/types';
 
 import { type InternalConnectionOptions } from './connection';
 import { Collation } from './collation';
+import Json from './data-types/json';
 
 export interface Parameter {
   type: DataType;
@@ -129,6 +130,7 @@ export const TYPE = {
   [UDT.id]: UDT,
   [TVP.id]: TVP,
   [Variant.id]: Variant,
+  [Json.id]: Json
 };
 
 /**
@@ -400,6 +402,13 @@ export const TYPE = {
  *     <td>✓</td>
  *     <td>-</td>
  *   </tr>
+ *  <tr>
+ *     <td><code>json</code></td>
+ *     <td><code>[[TYPES.Json]]</code></td>
+ *     <td><code>string|object</code></td>
+ *     <td>✓</td>
+ *     <td>-</td>
+ *   </tr>
  * </tbody>
  * </table>
  *
@@ -467,7 +476,8 @@ export const TYPES = {
   DateTimeOffset,
   UDT,
   TVP,
-  Variant
+  Variant,
+  Json
 };
 
 export const typeByName = TYPES;

src/data-types/json.ts

@@ -0,0 +1,59 @@
+import { type DataType } from '../data-type';
+const UNKNOWN_PLP_LEN = Buffer.from([0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff]);
+const PLP_TERMINATOR = Buffer.from([0x00, 0x00, 0x00, 0x00]);
+const MAX_NULL_LENGTH = Buffer.from([0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]);
+
+const Json: DataType = {
+  id: 0xF4,
+  type: 'JSON',
+  name: 'Json',
+
+  declaration: (parameter) => {
+    return 'json';
+  },
+  resolveLength: (parameter) => {
+    if ((parameter.value instanceof String || typeof (parameter.value) == 'string'))
+      return parameter.value.length;
+    else return JSON.stringify(parameter.value).length;
+  },
+
+  generateTypeInfo(parameter) {
+    return Buffer.from([this.id]);
+  },
+
+  generateParameterLength: (parameter, options) => {
+    const value = parameter.value as Buffer | null;
+    if (value == null) {
+      return MAX_NULL_LENGTH;
+    }
+    return UNKNOWN_PLP_LEN;
+  },
+
+  generateParameterData: function* (parameter, options) {
+    const value = parameter.value as Buffer | null;
+    if (value == null || (value?.length ?? 0) === 0) {
+      return;
+    }
+
+    const buffer = Buffer.alloc(4);
+    buffer.writeUInt32LE(value.length, 0);
+    yield buffer;
+    yield value;
+    yield PLP_TERMINATOR;
+  },
+
+  validate: (value, collation): Buffer | null => {
+    if (value == null) {
+      return null;
+    }
+
+    if (!(value instanceof String || typeof (value) == 'string'))
+      value = JSON.stringify(value);
+    else JSON.parse(value as string); // validate parsing
+
+    return Buffer.from(value, 'utf-8');
+  }
+};
+
+export default Json;
+module.exports = Json;