feat: Add script to mirror code to sqlc-gen-go (sqlc-dev#2952)

* feat(scripts): Mirror sqlc-gen-go to second repo

For easy forking, mirror the Go plugin to a separate read-only
repository.

* fix: Use correct import paths

Author: kyleconroy

scripts/mirror-go-plugin/main.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io/fs"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func main() {
+	flag.Parse()
+	// Assume it exists
+	loc := flag.Arg(0)
+
+	dir := filepath.Join("internal", "codegen", "golang")
+	err := filepath.Walk(dir, func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info.IsDir() {
+			return nil
+		}
+		contents, err := os.ReadFile(path)
+		if err != nil {
+			return err
+		}
+
+		newdir := filepath.Join(loc, "internal")
+		newpath := strings.Replace(path, dir, newdir, 1)
+
+		os.MkdirAll(filepath.Dir(newpath), 0755)
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/codegen/golang/opts"`),
+			[]byte(`"github.com/sqlc-dev/sqlc-gen-go/internal/opts"`))
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/plugin"`),
+			[]byte(`"github.com/sqlc-dev/plugin-sdk-go/plugin"`))
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/codegen/sdk"`),
+			[]byte(`"github.com/sqlc-dev/plugin-sdk-go/sdk"`))
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/metadata"`),
+			[]byte(`"github.com/sqlc-dev/plugin-sdk-go/metadata"`))
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/pattern"`),
+			[]byte(`"github.com/sqlc-dev/plugin-sdk-go/pattern"`))
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/debug"`),
+			[]byte(`"github.com/sqlc-dev/sqlc-gen-go/internal/debug"`))
+
+		contents = bytes.ReplaceAll(contents,
+			[]byte(`"github.com/sqlc-dev/sqlc/internal/inflection"`),
+			[]byte(`"github.com/sqlc-dev/sqlc-gen-go/internal/inflection"`))
+
+		if err := os.WriteFile(newpath, contents, 0644); err != nil {
+			return err
+		}
+		return nil
+	})
+
+	if err != nil {
+		fmt.Printf("error walking the path: %v\n", err)
+		return
+	}
+
+	{
+		path := filepath.Join("internal", "inflection", "singular.go")
+		contents, err := os.ReadFile(path)
+		if err != nil {
+			log.Fatal(err)
+		}
+		newpath := filepath.Join(loc, "internal", "inflection", "singular.go")
+		if err := os.WriteFile(newpath, contents, 0644); err != nil {
+			log.Fatal(err)
+		}
+	}
+
+}