feat(source): support Avro Union type

e2e_test/commands/sr_register

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# Register a schema to schema registry
+#
+# Usage: sr_register <subject> <schema>
+#
+# https://docs.confluent.io/platform/current/schema-registry/develop/api.html#post--subjects-(string-%20subject)-versions
+
+# Validate arguments
+if [[ $# -ne 2 ]]; then
+    echo "Usage: sr_register <subject> <schema>"
+    exit 1
+fi
+
+subject="$1"
+schema="$2"
+
+
+if [[ -z $subject || -z $schema ]]; then
+    echo "Error: Arguments cannot be empty"
+    exit 1
+fi
+
+echo "$schema" | jq '{"schema": tojson}' \
+| curl -X POST -H 'content-type:application/vnd.schemaregistry.v1+json' -d @- "${RISEDEV_SCHEMA_REGISTRY_URL}/subjects/${subject}/versions"

e2e_test/source_inline/kafka/avro/alter_source.slt

@@ -12,8 +12,7 @@ system ok
 rpk topic create 'avro_alter_source_test'
 
 system ok
-echo '{"type":"record","name":"Root","fields":[{"name":"foo","type":"string"}]}' | jq '{"schema": tojson}' \
-| curl -X POST -H 'content-type:application/json' -d @- "${RISEDEV_SCHEMA_REGISTRY_URL}/subjects/avro_alter_source_test-value/versions"
+sr_register avro_alter_source_test-value '{"type":"record","name":"Root","fields":[{"name":"foo","type":"string"}]}'
 
 statement ok
 create source s
@@ -27,8 +26,7 @@ FORMAT PLAIN ENCODE AVRO (
 
 # create a new version of schema and produce a message
 system ok
-echo '{"type":"record","name":"Root","fields":[{"name":"bar","type":"int","default":0},{"name":"foo","type":"string"}]}' | jq '{"schema": tojson}' \
-| curl -X POST -H 'content-type:application/json' -d @- "${RISEDEV_SCHEMA_REGISTRY_URL}/subjects/avro_alter_source_test-value/versions"
+sr_register avro_alter_source_test-value '{"type":"record","name":"Root","fields":[{"name":"bar","type":"int","default":0},{"name":"foo","type":"string"}]}'
 
 system ok
 echo '{"foo":"ABC", "bar":1}' | rpk topic produce --schema-id=topic avro_alter_source_test

e2e_test/source_inline/kafka/avro/union.slt

@@ -0,0 +1,175 @@
+control substitution on
+
+system ok
+rpk topic delete 'avro-union' || true; \
+(rpk sr subject delete 'avro-union-value' && rpk sr subject delete 'avro-union-value' --permanent) || true;
+rpk topic create avro-union
+
+system ok
+sr_register avro-union-value '
+{
+  "type": "record",
+  "name": "Root",
+  "fields": [
+    {
+      "name": "unionType",
+      "type": ["int", "string"]
+    },
+    {
+      "name": "unionTypeComplex",
+      "type": [
+        "null",
+        {"type": "record", "name": "Email","fields": [{"name":"inner","type":"string"}]},
+        {"type": "record", "name": "Fax","fields": [{"name":"inner","type":"int"}]},
+        {"type": "record", "name": "Sms","fields": [{"name":"inner","type":"int"}]}
+      ]
+    },
+    {
+        "name": "enumField",
+        "type": ["null", "int", {
+            "type": "enum",
+            "name": "myEnum",
+            "namespace": "my.namespace",
+            "symbols": ["A", "B", "C", "D"]
+        }],
+        "default": null
+    }
+  ]
+}
+'
+
+system ok
+cat<<EOF | rpk topic produce avro-union --schema-id=topic
+{"unionType": {"int":1}, "unionTypeComplex": {"Sms": {"inner":6}},  "enumField": {"my.namespace.myEnum": "A"}}
+{"unionType": {"string":"2"}, "unionTypeComplex": {"Fax": {"inner":6}}}
+{"unionType": {"int":3}, "unionTypeComplex": {"Email": {"inner":"[email protected]"}}, "enumField": {"int":66}}
+EOF
+
+statement error
+create source avro_union
+WITH (
+    ${RISEDEV_KAFKA_WITH_OPTIONS_COMMON},
+    topic = 'avro-union'
+)
+FORMAT PLAIN ENCODE AVRO (
+    schema.registry = '${RISEDEV_SCHEMA_REGISTRY_URL}'
+);
+----
+db error: ERROR: Failed to run the query
+
+Caused by these errors (recent errors listed first):
+  1: connector error
+  2: failed to convert Avro union to struct
+  3: Feature is not yet implemented: Avro named type used in Union type: Record(RecordSchema { name: Name { name: "Email", namespace: None }, aliases: None, doc: None, fields: [RecordField { name: "inner", doc: None, aliases: None, default: None, schema: String, order: Ascending, position: 0, custom_attributes: {} }], lookup: {"inner": 0}, attributes: {} })
+Tracking issue: https://github.com/risingwavelabs/risingwave/issues/17632
+
+
+# FIXME: The following is the current buggy result.
+
+
+# query ? rowsort
+# select * from avro_union
+# ----
+# ("([email protected])",,)
+# (,"(6)",)
+# (,"(6)",)
+
+# # Demonstrate how to access union variants (struct fields) below:
+# # Note that we need to use quotes.
+
+# query ? rowsort
+# select ("enumField")."my.namespace.myEnum" from avro_union;
+# ----
+# A
+# NULL
+# NULL
+
+# # To output the union’s tag (i.e. case in protobuf), a case-when can be used.
+# query ? rowsort
+# select
+# case
+#   when ("unionTypeComplex")."Sms" is not null then 'Sms'
+#   when ("unionTypeComplex")."Fax" is not null then 'Fax'
+#   when ("unionTypeComplex")."Email"  is not null then 'Email'
+#   else null -- optional
+# end
+# from avro_union;
+# ----
+# Email
+# Fax
+# Fax
+
+
+
+system ok
+rpk topic delete 'avro-union-simple' || true; \
+(rpk sr subject delete 'avro-union-simple-value' && rpk sr subject delete 'avro-union-simple-value' --permanent) || true;
+rpk topic create avro-union-simple
+
+system ok
+sr_register avro-union-simple-value '
+{
+  "type": "record",
+  "name": "Root",
+  "fields": [
+    {
+      "name": "unionType",
+      "type": ["int", "string", "null", "boolean"]
+    }
+  ]
+}
+'
+
+system ok
+cat<<EOF | rpk topic produce avro-union-simple --schema-id=topic
+{"unionType": {"int":1}}
+{"unionType": {"string":"2"}}
+{"unionType": {"boolean": true}}
+{"unionType": null}
+EOF
+
+statement ok
+create source avro_union
+WITH (
+    ${RISEDEV_KAFKA_WITH_OPTIONS_COMMON},
+    topic = 'avro-union-simple'
+)
+FORMAT PLAIN ENCODE AVRO (
+    schema.registry = '${RISEDEV_SCHEMA_REGISTRY_URL}'
+);
+
+
+query ? rowsort
+select * from avro_union
+----
+(,,t)
+(,2,)
+(1,,)
+NULL
+
+# Demonstrate how to access union variants (struct fields) below:
+# Note that we need to use quotes.
+
+query ? rowsort
+select ("unionType")."string" from avro_union;
+----
+2
+NULL
+NULL
+NULL
+
+# To output the union’s tag (i.e. case in protobuf), a case-when can be used.
+query ? rowsort
+select
+case
+  when ("unionType")."int" is not null then 'int'
+  when ("unionType")."string" is not null then 'string'
+  when ("unionType")."boolean"  is not null then 'boolean'
+  else null -- optional
+end
+from avro_union;
+----
+NULL
+boolean
+int
+string

src/common/src/types/mod.rs

@@ -573,6 +573,8 @@ pub trait ScalarRef<'a>: ScalarBounds<ScalarRefImpl<'a>> + 'a + Copy {
 macro_rules! scalar_impl_enum {
     ($( { $variant_name:ident, $suffix_name:ident, $scalar:ty, $scalar_ref:ty } ),*) => {
         /// `ScalarImpl` embeds all possible scalars in the evaluation framework.
+        ///
+        /// See `for_all_variants` for the definition.
         #[derive(Debug, Clone, PartialEq, Eq, EstimateSize)]
         pub enum ScalarImpl {
             $( $variant_name($scalar) ),*