Added support for destination table write preference in BQ Execute Plugin

Addressed PR comments: updated description, added documentation for the added feature

Formatted to fix failing tests

Refactor: Replace hardcoded write preference strings with JobInfo.WriteDisposition constants

Refactor: Simplify error message for invalid write preference validation

Refactor: Centralize valid write preferences in BigQueryExecute.Config

Refactor: Dynamically generate valid write preferences from JobInfo.WriteDisposition

Author: anshumanks

docs/BigQueryExecute-action.md

@@ -62,6 +62,11 @@ cache that will be flushed whenever tables in the query are modified.
 It is only applicable when users choose to store the query results in a BigQuery table.
 More information can be found [here](https://cloud.google.com/data-fusion/docs/how-to/customer-managed-encryption-keys)
 
+**Destination Table Write Preference**: Provides the following options as write preferences for the destination table:
+* **Write if Empty**: Only write if the table is empty
+* **Append to Table**: Add results to existing data. Schema should match.
+* **Overwrite Table**: Replace all existing data. Schema will also be overriden.
+
 **Row As Arguments**: Row as arguments. For example, if the query is 'select min(id) as min_id, max(id) as max_id from my_dataset.my_table',
 an arguments for 'min_id' and 'max_id' will be set based on the query results. Plugins further down the pipeline can then
 reference these values with macros ${min_id} and ${max_id}.

src/main/java/io/cdap/plugin/gcp/bigquery/action/BigQueryExecute.java

@@ -58,9 +58,11 @@
 
 import java.io.IOException;
 import java.time.Duration;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 
 /**
@@ -111,6 +113,7 @@ public void run(ActionContext context) throws Exception {
     String datasetProjectId = config.getDatasetProject();
     if (config.getStoreResults() && datasetProjectId != null && datasetName != null && tableName != null) {
       builder.setDestinationTable(TableId.of(datasetProjectId, datasetName, tableName));
+      builder.setWriteDisposition(JobInfo.WriteDisposition.valueOf(config.getWritePreference()));
     }
 
     // Enable or Disable the query cache to force live query evaluation.
@@ -274,6 +277,7 @@ public static final class Config extends AbstractBigQueryActionConfig {
     private static final String SQL = "sql";
     private static final String DATASET = "dataset";
     private static final String TABLE = "table";
+    private static final String WRITE_PREFERENCE = "writePreference";
     private static final String NAME_LOCATION = "location";
     public static final String NAME_BQ_JOB_LABELS = "jobLabels";
     private static final int ERROR_CODE_NOT_FOUND = 404;
@@ -290,6 +294,8 @@ public static final class Config extends AbstractBigQueryActionConfig {
     // Sn = a * (1 - r^n) / (r - 1)
     public static final long DEFULT_MAX_RETRY_DURATION_SECONDS = 63L;
     public static final int DEFAULT_READ_TIMEOUT = 120;
+    public static final Set<String> VALID_WRITE_PREFERENCES = Arrays.stream(JobInfo.WriteDisposition.values())
+        .map(Enum::name).collect(Collectors.toSet());
 
     @Description("Dialect of the SQL command. The value must be 'legacy' or 'standard'. " +
       "If set to 'standard', the query will use BigQuery's standard SQL: " +
@@ -398,13 +404,20 @@ public static final class Config extends AbstractBigQueryActionConfig {
     @Description("Timeout in seconds to read data from an established HTTP connection (Default value is 120).")
     private Integer readTimeout;
 
+    @Name(WRITE_PREFERENCE)
+    @Nullable
+    @Macro
+    @Description("Specifies if a job should overwrite or append the existing destination table if it already exists.")
+    private String writePreference;
+
     private Config(@Nullable String project, @Nullable String serviceAccountType, @Nullable String serviceFilePath,
                    @Nullable String serviceAccountJson, @Nullable String dataset, @Nullable String table,
                    @Nullable String location, @Nullable String cmekKey, @Nullable String dialect, @Nullable String sql,
                    @Nullable String mode, @Nullable Boolean storeResults, @Nullable String jobLabelKeyValue,
                    @Nullable String rowAsArguments, @Nullable Boolean retryOnBackendError,
                    @Nullable Long initialRetryDuration, @Nullable Long maxRetryDuration,
-                   @Nullable Double retryMultiplier, @Nullable Integer maxRetryCount, @Nullable Integer readTimeout) {
+                   @Nullable Double retryMultiplier, @Nullable Integer maxRetryCount, @Nullable Integer readTimeout,
+                   @Nullable String writePreference) {
       this.project = project;
       this.serviceAccountType = serviceAccountType;
       this.serviceFilePath = serviceFilePath;
@@ -425,6 +438,7 @@ private Config(@Nullable String project, @Nullable String serviceAccountType, @N
       this.maxRetryCount = maxRetryCount;
       this.retryMultiplier = retryMultiplier;
       this.readTimeout = readTimeout;
+      this.writePreference = writePreference;
     }
 
     public boolean isLegacySQL() {
@@ -451,6 +465,11 @@ public Boolean getStoreResults() {
       return storeResults == null || storeResults;
     }
 
+    public String getWritePreference() {
+      String defaultPreference = JobInfo.WriteDisposition.WRITE_EMPTY.name();
+      return Strings.isNullOrEmpty(writePreference) ? defaultPreference : writePreference.toUpperCase();
+    }
+
     public QueryJobConfiguration.Priority getMode() {
       return QueryJobConfiguration.Priority.valueOf(mode.toUpperCase());
     }
@@ -546,9 +565,25 @@ public void validate(FailureCollector failureCollector, Map<String, String> argu
         validateJobLabelKeyValue(failureCollector);
       }
 
+      if (!containsMacro(WRITE_PREFERENCE)) {
+        validateWritePreference(failureCollector, getWritePreference());
+      }
+
       failureCollector.getOrThrowException();
     }
 
+    void validateWritePreference(FailureCollector failureCollector, String writePreference) {
+      if (!VALID_WRITE_PREFERENCES.contains(writePreference)) {
+        failureCollector.addFailure(
+            String.format("Invalid write preference '%s'. Allowed values are '%s'.",
+                writePreference, VALID_WRITE_PREFERENCES.toString()
+            ),
+            "Please provide a valid write preference."
+        )
+        .withConfigProperty(WRITE_PREFERENCE);
+      }
+    }
+
     void validateJobLabelKeyValue(FailureCollector failureCollector) {
       BigQueryUtil.validateJobLabelKeyValue(jobLabelKeyValue, failureCollector, NAME_BQ_JOB_LABELS);
       // Verify retry configuration when retry on backend error is enabled and none of the retry configuration
@@ -677,6 +712,7 @@ public static class Builder {
       private Integer maxRetryCount;
       private Double retryMultiplier;
       private Integer readTimeout;
+      private String writePreference;
 
       public Builder setProject(@Nullable String project) {
         this.project = project;
@@ -778,6 +814,11 @@ public Builder setReadTimeout(@Nullable Integer readTimeout) {
         return this;
       }
 
+      public Builder setWritePreference(@Nullable String writePreference) {
+        this.writePreference = writePreference;
+        return this;
+      }
+
       public Config build() {
         return new Config(
           project,
@@ -799,7 +840,8 @@ public Config build() {
           maxRetryDuration,
           retryMultiplier,
           maxRetryCount,
-          readTimeout
+          readTimeout,
+          writePreference
         );
       }
     }

src/test/java/io/cdap/plugin/gcp/bigquery/action/BigQueryExecuteTest.java

@@ -25,6 +25,7 @@
 import com.google.cloud.bigquery.JobStatus;
 import com.google.cloud.bigquery.QueryJobConfiguration;
 import com.google.cloud.bigquery.TableResult;
+import com.google.common.collect.ImmutableSet;
 import io.cdap.cdap.api.metrics.Metrics;
 import io.cdap.cdap.etl.api.StageMetrics;
 import io.cdap.cdap.etl.api.action.ActionContext;
@@ -37,6 +38,7 @@
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
+import java.util.Set;
 
 public class BigQueryExecuteTest {
   @Mock
@@ -226,5 +228,24 @@ public void testValidateRetryConfigurationWithInvalidReadTimeout() {
             failureCollector.getValidationFailures().get(0).getMessage());
   }
 
+  @Test
+  public void testValidateWritePreferenceWithInvalidValue() {
+    config.validateWritePreference(failureCollector, "INVALID_PREFERENCE");
+
+    // Assert validation failure
+    Assert.assertEquals(1, failureCollector.getValidationFailures().size());
+    Assert.assertEquals(
+        String.format("Invalid write preference 'INVALID_PREFERENCE'. Allowed values are '%s'.",
+            config.VALID_WRITE_PREFERENCES.toString()
+        ),
+        failureCollector.getValidationFailures().get(0).getMessage()
+    );
+  }
+
+  @Test
+  public void testDefaultWritePreference() {
+    Assert.assertEquals(JobInfo.WriteDisposition.WRITE_EMPTY.name(), config.getWritePreference());
+  }
+
 }
 

widgets/BigQueryExecute-action.json

@@ -150,6 +150,29 @@
             "placeholder": "projects/<gcp-project-id>/locations/<key-location>/keyRings/<key-ring-name>/cryptoKeys/<key-name>"
           }
         },
+        {
+          "widget-type": "radio-group",
+          "label": "Destination Table Write Preference",
+          "name": "writePreference",
+          "widget-attributes": {
+            "layout": "vertical",
+            "default": "WRITE_EMPTY",
+            "options": [
+              {
+                "id": "WRITE_EMPTY",
+                "label": "Write if Empty"
+              },
+              {
+                "id": "WRITE_APPEND",
+                "label": "Append to Table"
+              },
+              {
+                "id": "WRITE_TRUNCATE",
+                "label": "Overwrite Table"
+              }
+            ]
+          }
+        },
         {
           "name": "rowAsArguments",
           "label": "Row As Arguments",
@@ -313,6 +336,10 @@
         {
           "type": "property",
           "name": "cmekKey"
+        },
+        {
+          "type": "property",
+          "name": "writePreference"
         }
       ]
     }