make WrapFunction not panic

parser_test.go

@@ -8,6 +8,6 @@ import (
 )
 
 func TestParser(t *testing.T) {
-	_, err := parser.Parse("SELECT 1")
+	_, err := parser.Parse("CREATE TABLE t (a TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP)")
 	require.NoError(t, err)
 }

pkg/sql/sem/tree/function_name.go

@@ -19,7 +19,6 @@ import (
 	"github.com/cockroachdb/cockroachdb-parser/pkg/sql/pgwire/pgerror"
 	"github.com/cockroachdb/cockroachdb-parser/pkg/sql/sem/catconstants"
 	"github.com/cockroachdb/errors"
-	"github.com/cockroachdb/redact"
 	"github.com/lib/pq/oid"
 )
 
@@ -144,7 +143,7 @@ type CustomBuiltinFunctionWrapper interface {
 func WrapFunction(n string) ResolvableFunctionReference {
 	fd, ok := FunDefs[n]
 	if !ok {
-		panic(errors.AssertionFailedf("function %s() not defined", redact.Safe(n)))
+		return ResolvableFunctionReference{&FunctionDefinition{Name: n}}
 	}
 	return ResolvableFunctionReference{fd}
 }

snapshot.sh

@@ -42,6 +42,9 @@ rm pkg/sql/lexbase/.gitignore pkg/sql/parser/.gitignore
 find pkg -type f -name '*_test.go' | xargs rm
 # sed replace any instances of cockroachdb
 find pkg -type f -name '*.go' | xargs sed -i '' -e 's_github\.com/cockroachdb/cockroach/_github.com/cockroachdb/cockroachdb-parser/_g'
+# replace WrapFunction
+sed -i '' -e 's_panic(errors.AssertionFailedf("function %s() not defined", redact.Safe(n)))_return ResolvableFunctionReference{\&FunctionDefinition{Name: n}}_g' pkg/sql/sem/tree/function_name.go
+goimports -w pkg/sql/sem/tree/function_name.go
 
 echo "Cleaning up go and testing everything works"
 go mod tidy