Fix Trino transpilation of nullable single field ROW generated from EXCLUDE

src/main/kotlin/org/partiql/scribe/targets/trino/TrinoTarget.kt

@@ -27,13 +27,15 @@ import org.partiql.scribe.asNonNullable
 import org.partiql.scribe.sql.SqlCalls
 import org.partiql.scribe.sql.SqlFeatures
 import org.partiql.scribe.sql.SqlTarget
+import org.partiql.types.AnyOfType
 import org.partiql.types.BoolType
 import org.partiql.types.CollectionType
 import org.partiql.types.DateType
 import org.partiql.types.DecimalType
 import org.partiql.types.FloatType
 import org.partiql.types.IntType
 import org.partiql.types.ListType
+import org.partiql.types.MissingType
 import org.partiql.types.NullType
 import org.partiql.types.NumberConstraint
 import org.partiql.types.SingleType
@@ -528,6 +530,16 @@ public open class TrinoTarget : SqlTarget() {
                     val elementType = elementType.toTrinoString()
                     head + elementType + ">"
                 }
+                is AnyOfType -> {
+                    // Filter out unknown types. Trino types are nullable by default. Once Scribe uses PLK 0.15+,
+                    // `StaticType`s will be nullable + missable by default, so this branch will not be needed.
+                    val typesWithoutUnknown = this.flatten().allTypes.filterNot { it is NullType || it is MissingType }
+                    if (typesWithoutUnknown.size != 1) {
+                        error("Not able to convert StaticType $this to Trino")
+                    }
+                    val singleType = typesWithoutUnknown.first()
+                    singleType.toTrinoString()
+                }
                 else -> TODO("Not able to convert StaticType $this to Trino")
             }
         }

src/test/resources/catalogs/default/datatypes/T_CHAR_16_NULL.ion

@@ -0,0 +1,32 @@
+{
+  type: "bag",
+  items: {
+    type: "struct",
+    constraints: [ closed, ordered, unique ],
+    fields: [
+      {
+        name: "foo",
+        type: {
+          type: "struct",
+          constraints: [ closed, ordered, unique ],
+          fields: [
+            {
+              name: "bar",
+              type: "string",
+            },
+            {
+              name: "keep",
+              type: [
+                {
+                  type: "char",
+                  length: 16
+                },
+                "null"
+              ]
+            }
+          ]
+        },
+      },
+    ]
+  }
+}

src/test/resources/catalogs/default/datatypes/T_INT32_NULL.ion

@@ -0,0 +1,26 @@
+{
+  type: "bag",
+  items: {
+    type: "struct",
+    constraints: [ closed, ordered, unique ],
+    fields: [
+      {
+        name: "foo",
+        type: {
+          type: "struct",
+          constraints: [ closed, ordered, unique ],
+          fields: [
+            {
+              name: "bar",
+              type: "string",
+            },
+            {
+              name: "keep",
+              type: [ "int32", "null" ]
+            },
+          ]
+        },
+      },
+    ]
+  }
+}

src/test/resources/catalogs/default/datatypes/T_STRING_16_NULL.ion

@@ -0,0 +1,32 @@
+{
+  type: "bag",
+  items: {
+    type: "struct",
+    constraints: [ closed, ordered, unique ],
+    fields: [
+      {
+        name: "foo",
+        type: {
+          type: "struct",
+          constraints: [ closed, ordered, unique ],
+          fields: [
+            {
+              name: "bar",
+              type: "string",
+            },
+            {
+              name: "keep",
+              type: [
+                {
+                  type: "string",
+                  length: 16
+                },
+                "null"
+              ]
+            }
+          ]
+        },
+      },
+    ]
+  }
+}

src/test/resources/catalogs/default/datatypes/T_STRING_NULL.ion

@@ -0,0 +1,26 @@
+{
+  type: "bag",
+  items: {
+    type: "struct",
+    constraints: [ closed, ordered, unique ],
+    fields: [
+      {
+        name: "foo",
+        type: {
+          type: "struct",
+          constraints: [ closed, ordered, unique ],
+          fields: [
+            {
+              name: "bar",
+              type: "string",
+            },
+            {
+              name: "keep",
+              type: [ "string", "null" ]
+            },
+          ]
+        },
+      },
+    ]
+  }
+}

src/test/resources/inputs/basics/exclude.sql

@@ -123,3 +123,19 @@ SELECT * EXCLUDE t.foo.bar FROM datatypes.T_TIME_6 AS t;
 -- timestamp(6)
 --#[exclude-31]
 SELECT * EXCLUDE t.foo.bar FROM datatypes.T_TIMESTAMP_6 AS t;
+
+-- union(string, null)
+--#[exclude-32]
+SELECT * EXCLUDE t.foo.bar FROM datatypes.T_STRING_NULL AS t;
+
+-- union(int32, null)
+--#[exclude-33]
+SELECT * EXCLUDE t.foo.bar FROM datatypes.T_INT32_NULL AS t;
+
+-- union(varchar(16), null)
+--#[exclude-34]
+SELECT * EXCLUDE t.foo.bar FROM datatypes.T_STRING_16_NULL AS t;
+
+-- union(char(16), null)
+--#[exclude-35]
+SELECT * EXCLUDE t.foo.bar FROM datatypes.T_CHAR_16_NULL AS t;

src/test/resources/outputs/trino/basics/exclude.sql

@@ -121,3 +121,19 @@ SELECT "$__EXCLUDE_ALIAS__"."t".* FROM (SELECT CAST(ROW(CAST(ROW("t"."foo"."keep
 -- timestamp(6)
 --#[exclude-31]
 SELECT "$__EXCLUDE_ALIAS__"."t".* FROM (SELECT CAST(ROW(CAST(ROW("t"."foo"."keep") AS ROW(keep TIMESTAMP(6)))) AS ROW(foo ROW(keep TIMESTAMP(6)))) AS "t" FROM "default"."datatypes"."T_TIMESTAMP_6" AS "t") AS "$__EXCLUDE_ALIAS__";
+
+-- union(string, null)
+--#[exclude-32]
+SELECT "$__EXCLUDE_ALIAS__"."t".* FROM (SELECT CAST(ROW(CAST(ROW("t"."foo"."keep") AS ROW(keep VARCHAR))) AS ROW(foo ROW(keep VARCHAR))) AS "t" FROM "default"."datatypes"."T_STRING_NULL" AS "t") AS "$__EXCLUDE_ALIAS__";
+
+-- union(int32, null)
+--#[exclude-33]
+SELECT "$__EXCLUDE_ALIAS__"."t".* FROM (SELECT CAST(ROW(CAST(ROW("t"."foo"."keep") AS ROW(keep INTEGER))) AS ROW(foo ROW(keep INTEGER))) AS "t" FROM "default"."datatypes"."T_INT32_NULL" AS "t") AS "$__EXCLUDE_ALIAS__";
+
+-- union(varchar(16), null)
+--#[exclude-34]
+SELECT "$__EXCLUDE_ALIAS__"."t".* FROM (SELECT CAST(ROW(CAST(ROW("t"."foo"."keep") AS ROW(keep VARCHAR(16)))) AS ROW(foo ROW(keep VARCHAR(16)))) AS "t" FROM "default"."datatypes"."T_STRING_16_NULL" AS "t") AS "$__EXCLUDE_ALIAS__";
+
+-- union(char(16), null)
+--#[exclude-35]
+SELECT "$__EXCLUDE_ALIAS__"."t".* FROM (SELECT CAST(ROW(CAST(ROW("t"."foo"."keep") AS ROW(keep CHAR(16)))) AS ROW(foo ROW(keep CHAR(16)))) AS "t" FROM "default"."datatypes"."T_CHAR_16_NULL" AS "t") AS "$__EXCLUDE_ALIAS__";