Add validation to prevent BigQuery view from creation when input schema contains required fields

.changelog/11101.txt

@@ -0,0 +1,3 @@
+```release-note:breaking-change
+bigquery: added validation to prevent table view creation if schema contains required fields for `google_bigquery_table` resource
+```

google-beta/services/bigquery/resource_bigquery_table.go

@@ -1593,6 +1593,9 @@ func resourceBigQueryTableCreate(d *schema.ResourceData, meta interface{}) error
 	}
 
 	if table.View != nil && table.Schema != nil {
+		if schemaHasRequiredFields(table.Schema) {
+			return errors.New("Schema cannot contain required fields when creating a view")
+		}
 
 		log.Printf("[INFO] Removing schema from table definition because BigQuery does not support setting schema on view creation")
 		schemaBack := table.Schema
@@ -2551,6 +2554,15 @@ func setEmptyPolicyTagsInSchema(field *bigquery.TableFieldSchema) {
 	}
 }
 
+func schemaHasRequiredFields(schema *bigquery.TableSchema) bool {
+	for _, field := range schema.Fields {
+		if "REQUIRED" == field.Mode {
+			return true
+		}
+	}
+	return false
+}
+
 func expandTimePartitioning(configured interface{}) *bigquery.TimePartitioning {
 	raw := configured.([]interface{})[0].(map[string]interface{})
 	tp := &bigquery.TimePartitioning{Type: raw["type"].(string)}

google-beta/services/bigquery/resource_bigquery_table_test.go

@@ -1497,6 +1497,23 @@ func TestAccBigQueryTable_invalidSchemas(t *testing.T) {
 	})
 }
 
+func TestAccBigQueryTable_schemaWithRequiredFieldAndView(t *testing.T) {
+	datasetID := fmt.Sprintf("tf_test_%s", acctest.RandString(t, 10))
+	tableID := fmt.Sprintf("tf_test_%s", acctest.RandString(t, 10))
+
+	acctest.VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckBigQueryTableDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config:      testAccBigQueryTableWithSchemaWithRequiredFieldAndView(datasetID, tableID),
+				ExpectError: regexp.MustCompile("Schema cannot contain required fields when creating a view"),
+			},
+		},
+	})
+}
+
 func TestAccBigQueryTable_TableReplicationInfo_ConflictsWithView(t *testing.T) {
 	t.Parallel()
 
@@ -3982,6 +3999,42 @@ resource "google_bigquery_table" "test" {
 `, datasetID, tableID)
 }
 
+func testAccBigQueryTableWithSchemaWithRequiredFieldAndView(datasetID, tableID string) string {
+	return fmt.Sprintf(`
+resource "google_bigquery_dataset" "test" {
+  dataset_id = "%s"
+}
+
+resource "google_bigquery_table" "test" {
+  deletion_protection = false
+  table_id   = "%s"
+  dataset_id = google_bigquery_dataset.test.dataset_id
+  schema = <<EOF
+  [
+    {
+      "name": "requiredField",
+      "type": "STRING",
+      "mode": "REQUIRED",
+      "description": "requiredField"
+    },
+    {
+      "name": "optionalField",
+      "type": "STRING",
+      "mode": "NULLABLE",
+      "description": "optionalField"
+    }
+  ]
+  EOF
+  view {
+    query = <<EOF
+      SELECT 'a' AS requiredField, 'b' AS optionalField
+    EOF
+    use_legacy_sql = false
+  }
+}
+`, datasetID, tableID)
+}
+
 func testAccBigQueryTableWithReplicationInfo(projectID, sourceDatasetID, sourceTableID, sourceMVID, replicaDatasetID, replicaMVID, sourceMVJobID, dropMVJobID, replicationIntervalExpr string) string {
 	return fmt.Sprintf(`
 resource "google_bigquery_dataset" "source" {

website/docs/guides/version_6_upgrade.html.markdown

@@ -102,6 +102,12 @@ Description of the change and how users should adjust their configuration (if ne
 
 ## Resources
 
+## Resource: `google_bigquery_table`
+
+### View creation now validates `schema`
+
+A `view` can no longer be created when `schema` contains required fields
+
 ## Resource: `google_sql_database_instance`
 
 ### `settings.ip_configuration.require_ssl` is now removed