feat: internal to Standard JSON Schema conversion COMPASS-8700

src/schema-convertors/internalToStandard.ts

@@ -1,12 +1,320 @@
-import { InternalSchema } from '..';
+import { ArraySchemaType, DocumentSchemaType, Schema as InternalSchema, SchemaType } from '../schema-analyzer';
 import { StandardJSONSchema } from '../types';
 
-export default function internalSchemaToStandard(
-  /* eslint @typescript-eslint/no-unused-vars: 0 */
+const InternalTypeToStandardTypeMap: Record<
+  SchemaType['name'] | 'Double' | 'BSONSymbol',
+  string | { $ref: string }
+> = {
+  Double: { $ref: '#/$defs/Double' },
+  Number: { $ref: '#/$defs/Double' },
+  String: 'string',
+  Document: 'object',
+  Array: 'array',
+  Binary: { $ref: '#/$defs/Binary' },
+  Undefined: { $ref: '#/$defs/Undefined' },
+  ObjectId: { $ref: '#/$defs/ObjectId' },
+  Boolean: 'boolean',
+  Date: { $ref: '#/$defs/Date' },
+  Null: 'null',
+  RegExp: { $ref: '#/$defs/RegExp' },
+  BSONRegExp: { $ref: '#/$defs/RegExp' },
+  DBRef: { $ref: '#/$defs/DBRef' },
+  DBPointer: { $ref: '#/$defs/DBPointer' },
+  BSONSymbol: { $ref: '#/$defs/BSONSymbol' },
+  Symbol: { $ref: '#/$defs/BSONSymbol' },
+  Code: { $ref: '#/$defs/Code' },
+  Int32: 'integer',
+  Timestamp: { $ref: '#/$defs/Timestamp' },
+  Long: 'integer',
+  Decimal128: { $ref: '#/$defs/Decimal' },
+  MinKey: { $ref: '#/$defs/MinKey' },
+  MaxKey: { $ref: '#/$defs/MaxKey' }
+};
+
+const RELAXED_EJSON_DEFINITIONS = Object.freeze({
+  ObjectId: {
+    type: 'object',
+    properties: {
+      $oid: {
+        type: 'string',
+        pattern: '^[0-9a-fA-F]{24}$'
+      }
+    },
+    required: ['$oid'],
+    additionalProperties: false
+  },
+  BSONSymbol: {
+    type: 'object',
+    properties: {
+      $symbol: {
+        type: 'string'
+      }
+    },
+    required: ['$symbol'],
+    additionalProperties: false
+  },
+  Double: {
+    oneOf: [
+      { type: 'number' },
+      {
+        enum: ['Infinity', '-Infinity', 'NaN']
+      }
+    ]
+  },
+  Decimal128: {
+    type: 'object',
+    properties: {
+      $numberDecimal: {
+        type: 'string'
+      }
+    },
+    required: ['$numberDecimal'],
+    additionalProperties: false
+  },
+  Binary: {
+    type: 'object',
+    properties: {
+      $binary: {
+        type: 'object',
+        properties: {
+          base64: {
+            type: 'string'
+          },
+          subType: {
+            type: 'string',
+            pattern: '^[0-9a-fA-F]{1,2}$' // BSON binary type as a one- or two-character hex string
+          }
+        },
+        required: ['base64', 'subType'],
+        additionalProperties: false
+      }
+    },
+    required: ['$binary'],
+    additionalProperties: false
+  },
+  Code: {
+    type: 'object',
+    properties: {
+      $code: {
+        type: 'string'
+      }
+    },
+    required: ['$code'],
+    additionalProperties: false
+  },
+  CodeWScope: {
+    type: 'object',
+    properties: {
+      $code: {
+        type: 'string'
+      },
+      $scope: {
+        type: 'object' // TODO: object is ejson object hmm
+      }
+    },
+    required: ['$code', '$scope'],
+    additionalProperties: false
+  },
+  Timestamp: {
+    type: 'object',
+    properties: {
+      $timestamp: {
+        type: 'object',
+        properties: {
+          t: {
+            type: 'integer',
+            minimum: 0
+          },
+          i: {
+            type: 'integer',
+            minimum: 0
+          }
+        },
+        required: ['t', 'i'],
+        additionalProperties: false
+      }
+    },
+    required: ['$timestamp'],
+    additionalProperties: false
+  },
+  RegExp: {
+    type: 'object',
+    properties: {
+      $regularExpression: {
+        type: 'object',
+        properties: {
+          pattern: {
+            type: 'string'
+          },
+          options: {
+            type: 'string',
+            pattern: '^[gimuy]*$'
+          }
+        },
+        required: ['pattern'],
+        additionalProperties: false
+      }
+    },
+    required: ['$regularExpression'],
+    additionalProperties: false
+  },
+  DBPointer: {
+    type: 'object',
+    properties: {
+      $dbPointer: {
+        type: 'object',
+        properties: {
+          $ref: {
+            type: 'string'
+          },
+          $id: {
+            $ref: '#/$defs/Decimal'
+          }
+        },
+        required: ['$ref', '$id'],
+        additionalProperties: false
+      }
+    },
+    required: ['$dbPointer'],
+    additionalProperties: false
+  },
+  Date: {
+    type: 'object',
+    properties: {
+      $date: {
+        type: 'string',
+        format: 'date-time'
+      }
+    },
+    required: ['$date'],
+    additionalProperties: false
+  },
+  DBRef: {
+    type: 'object',
+    properties: {
+      $ref: {
+        type: 'string'
+      },
+      $id: {},
+      $db: {
+        type: 'string'
+      }
+    },
+    required: ['$ref', '$id'],
+    additionalProperties: true
+  },
+  MinKey: {
+    type: 'object',
+    properties: {
+      $minKey: {
+        type: 'integer',
+        const: 1
+      }
+    },
+    required: ['$minKey'],
+    additionalProperties: false
+  },
+  MaxKey: {
+    type: 'object',
+    properties: {
+      $maxKey: {
+        type: 'integer',
+        const: 1
+      }
+    },
+    required: ['$maxKey'],
+    additionalProperties: false
+  },
+  Undefined: {
+    type: 'object',
+    properties: {
+      $undefined: {
+        type: 'boolean',
+        const: true
+      }
+    },
+    required: ['$undefined'],
+    additionalProperties: false
+  }
+});
+
+const convertInternalType = (type: string) => {
+  const bsonType = InternalTypeToStandardTypeMap[type];
+  if (!bsonType) throw new Error(`Encountered unknown type: ${type}`);
+  return bsonType;
+};
+
+async function allowAbort(signal?: AbortSignal) {
+  return new Promise<void>((resolve, reject) =>
+    setTimeout(() => {
+      if (signal?.aborted) return reject(signal?.reason || new Error('Operation aborted'));
+      resolve();
+    })
+  );
+}
+
+async function parseType(type: SchemaType, signal?: AbortSignal): Promise<StandardJSONSchema> {
+  await allowAbort(signal);
+  const schema: StandardJSONSchema = {
+    bsonType: convertInternalType(type.bsonType)
+  };
+  switch (type.bsonType) {
+    case 'Array':
+      schema.items = await parseTypes((type as ArraySchemaType).types);
+      break;
+    case 'Document':
+      Object.assign(schema,
+        await parseFields((type as DocumentSchemaType).fields, signal)
+      );
+      break;
+  }
+
+  return schema;
+}
+
+async function parseTypes(types: SchemaType[], signal?: AbortSignal): Promise<StandardJSONSchema> {
+  await allowAbort(signal);
+  const definedTypes = types.filter(type => type.bsonType.toLowerCase() !== 'undefined');
+  const isSingleType = definedTypes.length === 1;
+  if (isSingleType) {
+    return parseType(definedTypes[0], signal);
+  }
+  const parsedTypes = await Promise.all(definedTypes.map(type => parseType(type, signal)));
+  if (definedTypes.some(type => ['Document', 'Array'].includes(type.bsonType))) {
+    return {
+      anyOf: parsedTypes
+    };
+  }
+  return {
+    bsonType: definedTypes.map((type) => convertInternalType(type.bsonType))
+  };
+}
+
+async function parseFields(fields: DocumentSchemaType['fields'], signal?: AbortSignal): Promise<{
+  required: StandardJSONSchema['required'],
+  properties: StandardJSONSchema['properties'],
+}> {
+  const required = [];
+  const properties: StandardJSONSchema['properties'] = {};
+  for (const field of fields) {
+    if (field.probability === 1) required.push(field.name);
+    properties[field.name] = await parseTypes(field.types, signal);
+  }
+
+  return { required, properties };
+}
+
+export default async function internalSchemaToMongodb(
   internalSchema: InternalSchema,
   options: {
     signal?: AbortSignal
-}): Promise<StandardJSONSchema> {
-  // TODO: COMPASS-8700
-  return Promise.resolve({} as StandardJSONSchema);
+} = {}): Promise<StandardJSONSchema> {
+  const { required, properties } = await parseFields(internalSchema.fields, options.signal);
+  const schema: StandardJSONSchema = {
+    bsonType: 'object',
+    required,
+    properties,
+    $defs: RELAXED_EJSON_DEFINITIONS
+  };
+  return schema;
 }