fix(compiler): prevent schema parse failures by ignoring psql meta commands

Resolves #4065

Author: andrewmbenton

internal/compiler/compile.go

@@ -1,6 +1,7 @@
 package compiler
 
 import (
+	"bufio"
 	"errors"
 	"fmt"
 	"io"
@@ -38,6 +39,7 @@ func (c *Compiler) parseCatalog(schemas []string) error {
 			continue
 		}
 		contents := migrations.RemoveRollbackStatements(string(blob))
+		contents = removePsqlMetaCommands(contents)
 		c.schema = append(c.schema, contents)
 		stmts, err := c.parser.Parse(strings.NewReader(contents))
 		if err != nil {
@@ -57,6 +59,19 @@ func (c *Compiler) parseCatalog(schemas []string) error {
 	return nil
 }
 
+func removePsqlMetaCommands(contents string) string {
+	s := bufio.NewScanner(strings.NewReader(contents))
+	var lines []string
+	for s.Scan() {
+		line := s.Text()
+		if strings.HasPrefix(line, `\`) {
+			continue
+		}
+		lines = append(lines, line)
+	}
+	return strings.Join(lines, "\n")
+}
+
 func (c *Compiler) parseQueries(o opts.Parser) (*Result, error) {
 	var q []*Query
 	merr := multierr.New()

internal/endtoend/testdata/pg_dump/schema.sql

@@ -5,6 +5,8 @@
 -- Dumped from database version 15.3 (Debian 15.3-1.pgdg120+1)
 -- Dumped by pg_dump version 15.3
 
+\restrict auwherpfqaiuwrhgp
+
 SET statement_timeout = 0;
 SET lock_timeout = 0;
 SET idle_in_transaction_session_timeout = 0;