feat: add support for missing value interpretation

src/managedwriter/json_writer.ts

@@ -15,11 +15,16 @@
 import * as protobuf from 'protobufjs';
 import * as protos from '../../protos/protos';
 import {PendingWrite} from './pending_write';
-import {StreamConnection, RemoveListener} from './stream_connection';
+import {RemoveListener} from './stream_connection';
 import * as adapt from '../adapt';
-import {Writer} from './writer';
+import {Writer, WriterOptions} from './writer';
 
 type TableSchema = protos.google.cloud.bigquery.storage.v1.ITableSchema;
+type MissingValueInterpretation =
+  protos.google.cloud.bigquery.storage.v1.AppendRowsRequest['defaultMissingValueInterpretation'];
+type MissingValueInterpretationMap = {
+  [column: string]: MissingValueInterpretation;
+};
 type IInt64Value = protos.google.protobuf.IInt64Value;
 type IDescriptorProto = protos.google.protobuf.IDescriptorProto;
 type DescriptorProto = protos.google.protobuf.DescriptorProto;
@@ -55,16 +60,10 @@ export class JSONWriter {
   /**
    * Creates a new JSONWriter instance.
    *
-   * @param {Object} params - The parameters for the JSONWriter.
-   * @param {StreamConnection} params.connection - The stream connection
-   *   to the BigQuery streaming insert operation.
-   * @param {IDescriptorProto} params.protoDescriptor - The proto descriptor
-   *   for the JSON rows.
+   * @param {WriterOptions} params - The parameters for the JSONWriter.
+   *   See WriterOptions docs for more information.
    */
-  constructor(params: {
-    connection: StreamConnection;
-    protoDescriptor: IDescriptorProto;
-  }) {
+  constructor(params: WriterOptions) {
     const {connection, protoDescriptor} = params;
     this._writer = new Writer(params);
     this._schemaListener = connection.onSchemaUpdated(this.onSchemaUpdated);
@@ -94,6 +93,30 @@ export class JSONWriter {
     this._writer.setProtoDescriptor(protoDescriptor);
   }
 
+  /**
+   * Update how missing values are interpreted by for the given stream.
+   *
+   * @param {MissingValueInterpretation} defaultMissingValueInterpretation
+   */
+  setDefaultMissingValueInterpretation(
+    defaultMissingValueInterpretation: MissingValueInterpretation
+  ) {
+    this._writer.setDefaultMissingValueInterpretation(
+      defaultMissingValueInterpretation
+    );
+  }
+
+  /**
+   * Update how missing values are interpreted for individual columns.
+   *
+   * @param {MissingValueInterpretationMap} missingValueInterpretations
+   */
+  setMissingValueInterpretations(
+    missingValueInterpretations: MissingValueInterpretationMap
+  ) {
+    this._writer.setMissingValueInterpretations(missingValueInterpretations);
+  }
+
   /**
    * Writes a JSONList that contains objects to be written to the BigQuery table by first converting
    * the JSON data to protobuf messages, then using Writer's appendRows() to write the data at current end

src/managedwriter/writer.ts

@@ -24,9 +24,60 @@ type ProtoData =
   protos.google.cloud.bigquery.storage.v1.AppendRowsRequest.IProtoData;
 type IDescriptorProto = protos.google.protobuf.IDescriptorProto;
 type DescriptorProto = protos.google.protobuf.DescriptorProto;
+type MissingValueInterpretation =
+  AppendRowRequest['defaultMissingValueInterpretation'];
+type MissingValueInterpretationMap = {
+  [column: string]: MissingValueInterpretation;
+};
 
 const DescriptorProto = protos.google.protobuf.DescriptorProto;
 
+export interface WriterOptions {
+  /** The stream connection to the BigQuery streaming insert operation. */
+  connection: StreamConnection;
+
+  /** The proto descriptor for the stream. */
+  protoDescriptor: IDescriptorProto;
+
+  /**
+   * Controls how missing values are interpreted by for a given stream.
+   * `missingValueInterpretations` set for individual colums can override the default chosen
+   * with this option.
+   *
+   * For example, if you want to write
+   * `NULL` instead of using default values for some columns, you can set
+   * `defaultMissingValueInterpretation` to `DEFAULT_VALUE` and at the same
+   * time, set `missingValueInterpretations` to `NULL_VALUE` on those columns.
+   */
+  defaultMissingValueInterpretation?: MissingValueInterpretation;
+
+  /**
+   * Control how missing values are interpreted for individual columns.
+   *
+   * You must provide an object to indicate how to interpret missing value for some fields. Missing
+   * values are fields present in user schema but missing in rows. The key is
+   * the field name. The value is the interpretation of missing values for the
+   * field.
+   *
+   * For example, the following option would indicate that missing values in the "foo"
+   * column are interpreted as null, whereas missing values in the "bar" column are
+   * treated as the default value:
+   *
+   * {
+   *     "foo": 'DEFAULT_VALUE',
+   *		 "bar": 'NULL_VALUE',
+   * }
+   *
+   * If a field is not in this object and has missing values, the missing values
+   * in this field are interpreted as NULL unless overridden with a default missing
+   * value interpretation.
+   *
+   * Currently, field name can only be top-level column name, can't be a struct
+   * field path like 'foo.bar'.
+   */
+  missingValueInterpretations?: MissingValueInterpretationMap;
+}
+
 /**
  * A BigQuery Storage API Writer that can be used to write data into BigQuery Table
  * using the Storage API.
@@ -37,23 +88,26 @@ const DescriptorProto = protos.google.protobuf.DescriptorProto;
 export class Writer {
   private _protoDescriptor: DescriptorProto;
   private _streamConnection: StreamConnection;
+  private _defaultMissingValueInterpretation?: MissingValueInterpretation;
+  private _missingValueInterpretations?: MissingValueInterpretationMap;
 
   /**
    * Creates a new Writer instance.
    *
-   * @param {Object} params - The parameters for the JSONWriter.
-   * @param {StreamConnection} params.connection - The stream connection
-   *   to the BigQuery streaming insert operation.
-   * @param {IDescriptorProto} params.protoDescriptor - The proto descriptor
-   *   for the JSON rows.
+   * @param {WriterOptions} params - The parameters for the Writer.
+   *   See WriterOptions docs for more information.
    */
-  constructor(params: {
-    connection: StreamConnection;
-    protoDescriptor: IDescriptorProto;
-  }) {
-    const {connection, protoDescriptor} = params;
+  constructor(params: WriterOptions) {
+    const {
+      connection,
+      protoDescriptor,
+      missingValueInterpretations,
+      defaultMissingValueInterpretation,
+    } = params;
     this._streamConnection = connection;
     this._protoDescriptor = new DescriptorProto(protoDescriptor);
+    this._defaultMissingValueInterpretation = defaultMissingValueInterpretation;
+    this._missingValueInterpretations = missingValueInterpretations;
   }
 
   /**
@@ -72,6 +126,28 @@ export class Writer {
     }
   }
 
+  /**
+   * Update how missing values are interpreted by for the given stream.
+   *
+   * @param {MissingValueInterpretation} defaultMissingValueInterpretation
+   */
+  setDefaultMissingValueInterpretation(
+    defaultMissingValueInterpretation: MissingValueInterpretation
+  ) {
+    this._defaultMissingValueInterpretation = defaultMissingValueInterpretation;
+  }
+
+  /**
+   * Update how missing values are interpreted for individual columns.
+   *
+   * @param {MissingValueInterpretationMap} missingValueInterpretations
+   */
+  setMissingValueInterpretations(
+    missingValueInterpretations: MissingValueInterpretationMap
+  ) {
+    this._missingValueInterpretations = missingValueInterpretations;
+  }
+
   /**
    * Schedules the writing of rows at given offset.
    *
@@ -97,6 +173,10 @@ export class Writer {
           protoDescriptor: this._protoDescriptor.toJSON(),
         },
       },
+      defaultMissingValueInterpretation:
+        this._defaultMissingValueInterpretation,
+      missingValueInterpretations: this
+        ._missingValueInterpretations as AppendRowRequest['missingValueInterpretations'],
       offset,
     };
 

system-test/managed_writer_client_test.ts

@@ -554,6 +554,105 @@ describe('managedwriter.WriterClient', () => {
     }).timeout(30 * 1000);
   });
 
+  it('should fill default values when MissingValuesInterpretation is set', async () => {
+    bqWriteClient.initialize();
+    const client = new WriterClient();
+    client.setClient(bqWriteClient);
+
+    const updatedSchema: TableSchema = {
+      fields: [
+        ...(schema.fields || []),
+        {
+          name: 'id',
+          type: 'STRING',
+          defaultValueExpression: 'GENERATE_UUID()',
+        },
+        {
+          name: 'created_at',
+          type: 'TIMESTAMP',
+          defaultValueExpression: 'CURRENT_TIMESTAMP()',
+        },
+        {
+          name: 'updated_at',
+          type: 'TIMESTAMP',
+          defaultValueExpression: 'CURRENT_TIMESTAMP()',
+        },
+      ],
+    };
+    const [table] = await bigquery
+      .dataset(datasetId)
+      .createTable(tableId + '_default_values', {schema: updatedSchema});
+    const parent = `projects/${projectId}/datasets/${datasetId}/tables/${table.id}`;
+
+    const storageSchema =
+      adapt.convertBigQuerySchemaToStorageTableSchema(updatedSchema);
+    const protoDescriptor: DescriptorProto =
+      adapt.convertStorageSchemaToProto2Descriptor(storageSchema, 'root');
+
+    // Row 1
+    const row1 = {
+      customer_name: 'Ada Lovelace',
+      row_num: 1,
+    };
+
+    // Row 2
+    const row2 = {
+      customer_name: 'Alan Turing',
+      row_num: 2,
+    };
+
+    try {
+      const connection = await client.createStreamConnection({
+        streamType: managedwriter.PendingStream,
+        destinationTable: parent,
+      });
+
+      const streamId = connection.getStreamId();
+      const writer = new JSONWriter({
+        connection,
+        protoDescriptor,
+        defaultMissingValueInterpretation: 'DEFAULT_VALUE',
+        missingValueInterpretations: {
+          updated_at: 'NULL_VALUE',
+        },
+      });
+
+      const pw = writer.appendRows([row1, row2], 0);
+      const result = await pw.getResult();
+
+      assert.equal(result.error, null);
+
+      const res = await connection.finalize();
+      connection.close();
+      assert.equal(res?.rowCount, 2);
+
+      const commitResponse = await client.batchCommitWriteStream({
+        parent,
+        writeStreams: [streamId],
+      });
+      assert.equal(commitResponse.streamErrors?.length, 0);
+
+      const [rows] = await bigquery.query(
+        `SELECT * FROM \`${projectId}.${datasetId}.${table.id}\` order by row_num`
+      );
+
+      assert.strictEqual(rows.length, 2);
+      const first = rows[0];
+      assert.notEqual(first.id, null);
+      assert.notEqual(first.created_at, null);
+      assert.equal(first.updated_at, null);
+
+      const second = rows[1];
+      assert.notEqual(second.id, null);
+      assert.notEqual(second.created_at, null);
+      assert.equal(second.updated_at, null);
+
+      writer.close();
+    } finally {
+      client.close();
+    }
+  });
+
   describe('Error Scenarios', () => {
     it('send request with mismatched proto descriptor', async () => {
       bqWriteClient.initialize();