feat: add the bm:seed command

Validates a whole JSON file (course keys, meeting numbers, values, dates)
and upserts meetings, courses, class sessions, deadlines and readings in
one transaction, matched on their natural identity. Prints a created,
updated and unchanged summary; --dry-run only validates. Ships a small
example fixture with made-up data.

console/seed.go

@@ -0,0 +1,58 @@
+// Code generated by summer make. DO NOT EDIT.
+
+package console
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"git.golem15.com/golem15/summercms/modules/bonfire"
+	"git.golem15.com/jakub/sm-bm-plugin/classes"
+	"gorm.io/gorm"
+)
+
+// SeedCommand returns the bm:seed console command. withDB runs the
+// command's work with the application's database; the plugin supplies it.
+func SeedCommand(withDB func(ctx context.Context, fn func(*gorm.DB) error) error) bonfire.Command {
+	return bonfire.Command{
+		Name:        "bm:seed",
+		Description: "Upsert meetings, courses, class sessions, deadlines and readings from a JSON file",
+		Args:        []bonfire.Arg{{Name: "file", Description: "Path of the seed JSON file", Required: true}},
+		Flags: []bonfire.Flag{
+			{Name: "dry-run", Description: "Validate the file without writing", Bare: true},
+		},
+		Run: func(ctx context.Context, in bonfire.Input, out bonfire.Output) error {
+			path, _ := in.Argument("file")
+			if path == "" {
+				return fmt.Errorf("bm:seed: a file is required")
+			}
+			fh, err := os.Open(path)
+			if err != nil {
+				return fmt.Errorf("bm:seed: %w", err)
+			}
+			defer fh.Close()
+			file, err := classes.ParseSeed(fh)
+			if err != nil {
+				return err
+			}
+			if err := file.Validate(); err != nil {
+				return fmt.Errorf("bm:seed: %s is not valid, nothing was written:\n%w", path, err)
+			}
+			if dry, _ := in.Flag("dry-run"); dry == "true" {
+				out.Success(fmt.Sprintf("%s is valid: %d meetings, %d courses, %d class sessions, %d deadlines, %d readings", path,
+					len(file.Meetings), len(file.Courses), len(file.ClassSessions), len(file.Deadlines), len(file.Readings)))
+				return nil
+			}
+			return withDB(ctx, func(db *gorm.DB) error {
+				sum, err := classes.Seed(ctx, db, file)
+				if err != nil {
+					return fmt.Errorf("bm:seed: nothing was written: %w", err)
+				}
+				out.Table([]string{"kind", "created", "updated", "unchanged"}, sum.Rows())
+				out.Success("bm:seed: " + path + " applied")
+				return nil
+			})
+		},
+	}
+}

console/seed_test.go

@@ -0,0 +1,69 @@
+package console_test
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"git.golem15.com/golem15/summercms/modules/bonfire"
+	"git.golem15.com/jakub/sm-bm-plugin/console"
+	"gorm.io/gorm"
+)
+
+func TestSeedCommandShape(t *testing.T) {
+	cmd := console.SeedCommand(nil)
+	if cmd.Name != "bm:seed" || cmd.Description == "" {
+		t.Errorf("command = %q %q", cmd.Name, cmd.Description)
+	}
+	if len(cmd.Args) != 1 || cmd.Args[0].Name != "file" || !cmd.Args[0].Required {
+		t.Errorf("Args = %+v, want one required file argument", cmd.Args)
+	}
+}
+
+func TestSeedCommandChecksTheFileBeforeTheDatabase(t *testing.T) {
+	called := false
+	withDB := func(ctx context.Context, fn func(*gorm.DB) error) error {
+		called = true
+		return errors.New("no database in this test")
+	}
+	cmds := []bonfire.Command{console.SeedCommand(withDB)}
+	dir := t.TempDir()
+	invalid := filepath.Join(dir, "invalid.json")
+	if err := os.WriteFile(invalid, []byte(`{"readings": [{"course": "ghost", "title": "X"}]}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	broken := filepath.Join(dir, "broken.json")
+	if err := os.WriteFile(broken, []byte(`{"courses": [`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	var out bytes.Buffer
+	for _, args := range [][]string{nil, {filepath.Join(dir, "missing.json")}, {broken}, {invalid}} {
+		if err := bonfire.Call(context.Background(), cmds, "bm:seed", args, &out); err == nil {
+			t.Errorf("bm:seed %v succeeded", args)
+		}
+	}
+	err := bonfire.Call(context.Background(), cmds, "bm:seed", []string{invalid}, &out)
+	if err == nil || !strings.Contains(err.Error(), "nothing was written") || !strings.Contains(err.Error(), "ghost") {
+		t.Errorf("invalid file error = %v", err)
+	}
+	if called {
+		t.Error("bm:seed reached the database with an invalid file")
+	}
+
+	out.Reset()
+	if err := bonfire.Call(context.Background(), cmds, "bm:seed", []string{"../testdata/seed.example.json", "--dry-run"}, &out); err != nil {
+		t.Fatalf("dry run: %v", err)
+	}
+	if called || !strings.Contains(out.String(), "3 courses") {
+		t.Errorf("dry run called=%v output %q", called, out.String())
+	}
+
+	err = bonfire.Call(context.Background(), cmds, "bm:seed", []string{"../testdata/seed.example.json"}, &out)
+	if !called || err == nil {
+		t.Errorf("valid file: called=%v err=%v, want the withDB error", called, err)
+	}
+}