Ignore unknown functions during SQL validation (#226)

Co-authored-by: Kyle Conroy <[email protected]>

Author: Cyberax

internal/dinosql/parser.go

@@ -1254,7 +1254,14 @@ func resolveCatalogRefs(c core.Catalog, rvs []nodes.RangeVar, args []paramRef) (
 			}
 			fun, err := c.LookupFunctionN(fqn, len(n.Args.Items))
 			if err != nil {
-				return nil, err
+				// Synthesize a function on the fly to avoid returning with an error
+				// for an unknown Postgres function (e.g. defined in an extension)
+				fun = core.Function{
+					Name:       fqn.Rel,
+					ArgN:       len(n.Args.Items),
+					Arguments:  nil,
+					ReturnType: "any",
+				}
 			}
 			for i, item := range n.Args.Items {
 				pr, ok := item.(nodes.ParamRef)

internal/dinosql/query_test.go

@@ -927,6 +927,18 @@ func TestComparisonOperators(t *testing.T) {
 	}
 }
 
+func TestUnknownFunctions(t *testing.T) {
+	stmt :=  `
+		CREATE TABLE foo (id text not null);
+		-- name: ListFoos :one
+		SELECT id FROM foo WHERE id = frobnicate($1);
+		`
+	_, err := parseSQL(stmt)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestInvalidQueries(t *testing.T) {
 	for i, tc := range []struct {
 		stmt string