Add unified posts database groundwork (#2)

Adds self-referencing post and post-vote tables, generated schema models, and an idempotent snapshot migration that preserves the legacy tables during the staged application cutover. Co-authored-by: codegirl-007 <s.raide@gmail.com>
2026-08-27 07:05:24 +00:00
parent 418ef93da5
commit c5ef15ae1f
4 changed files with 335 additions and 0 deletions
@@ -0,0 +1,213 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/google/uuid"
+)
+
+func TestMigratePostsCopiesLegacyData(t *testing.T) {
+	rawURL := strings.TrimSpace(os.Getenv("TEST_DATABASE_URL"))
+	if rawURL == "" {
+		t.Skip("TEST_DATABASE_URL is not set")
+	}
+	dsn, err := postgresDSN(rawURL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	db, err := sql.Open("pgx", dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	ctx := context.Background()
+	conn, err := db.Conn(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+
+	schemaName := "test_posts_" + strings.ReplaceAll(uuid.NewString(), "-", "")
+	if _, err := conn.ExecContext(ctx, "CREATE SCHEMA "+schemaName); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		_, _ = conn.ExecContext(context.Background(), "SET search_path TO public")
+		_, _ = conn.ExecContext(context.Background(), "DROP SCHEMA "+schemaName+" CASCADE")
+	}()
+	if _, err := conn.ExecContext(ctx, "SET search_path TO "+schemaName); err != nil {
+		t.Fatal(err)
+	}
+
+	legacySchema := `
+CREATE TABLE users (
+  id TEXT PRIMARY KEY
+);
+CREATE TABLE questions (
+  id TEXT PRIMARY KEY,
+  author_id TEXT NOT NULL REFERENCES users(id),
+  title TEXT NOT NULL,
+  body TEXT NOT NULL,
+  city TEXT NOT NULL DEFAULT '',
+  hunt_date TEXT NOT NULL,
+  hidden INTEGER NOT NULL DEFAULT 0,
+  created_at TEXT NOT NULL
+);
+CREATE TABLE answers (
+  question_id TEXT PRIMARY KEY REFERENCES questions(id) ON DELETE CASCADE,
+  author_id TEXT NOT NULL REFERENCES users(id),
+  body TEXT NOT NULL,
+  created_at TEXT NOT NULL,
+  updated_at TEXT NOT NULL
+);
+CREATE TABLE votes (
+  user_id TEXT NOT NULL REFERENCES users(id),
+  question_id TEXT NOT NULL REFERENCES questions(id) ON DELETE CASCADE,
+  value INTEGER NOT NULL CHECK (value IN (-1, 1)),
+  PRIMARY KEY (user_id, question_id)
+);`
+	if err := applySchema(ctx, conn, legacySchema); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := conn.ExecContext(ctx, `
+INSERT INTO users (id) VALUES ('homeowner'), ('plumber');
+INSERT INTO questions (id, author_id, title, body, city, hunt_date, hidden, created_at)
+VALUES ('question-1', 'homeowner', 'Leaky sink', 'It drips.', 'Oakland', '2026-08-26', 0, '2026-08-26T08:00:00Z');
+INSERT INTO answers (question_id, author_id, body, created_at, updated_at)
+VALUES ('question-1', 'plumber', 'Replace the cartridge.', '2026-08-26T09:00:00Z', '2026-08-26T09:05:00Z');
+INSERT INTO votes (user_id, question_id, value)
+VALUES ('homeowner', 'question-1', 1);`); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := migratePosts(ctx, conn); err != nil {
+		t.Fatal(err)
+	}
+	if err := migratePosts(ctx, conn); err != nil {
+		t.Fatalf("migration is not idempotent: %v", err)
+	}
+
+	var postCount, voteCount, legacyQuestionCount, legacyAnswerCount int
+	if err := conn.QueryRowContext(ctx, "SELECT count(*) FROM posts").Scan(&postCount); err != nil {
+		t.Fatal(err)
+	}
+	if err := conn.QueryRowContext(ctx, "SELECT count(*) FROM post_votes").Scan(&voteCount); err != nil {
+		t.Fatal(err)
+	}
+	if err := conn.QueryRowContext(ctx, "SELECT count(*) FROM questions").Scan(&legacyQuestionCount); err != nil {
+		t.Fatal(err)
+	}
+	if err := conn.QueryRowContext(ctx, "SELECT count(*) FROM answers").Scan(&legacyAnswerCount); err != nil {
+		t.Fatal(err)
+	}
+	if postCount != 2 || voteCount != 1 || legacyQuestionCount != 1 || legacyAnswerCount != 1 {
+		t.Fatalf(
+			"counts posts=%d votes=%d legacy questions=%d answers=%d",
+			postCount,
+			voteCount,
+			legacyQuestionCount,
+			legacyAnswerCount,
+		)
+	}
+
+	var rootParent sql.NullString
+	var rootAuthor, title, rootBody, city, postDate, rootCreated, rootUpdated string
+	if err := conn.QueryRowContext(ctx, `
+SELECT parent_id, author_id, title, body, city, post_date, created_at, updated_at
+FROM posts
+WHERE id = 'question-1'`).Scan(
+		&rootParent,
+		&rootAuthor,
+		&title,
+		&rootBody,
+		&city,
+		&postDate,
+		&rootCreated,
+		&rootUpdated,
+	); err != nil {
+		t.Fatal(err)
+	}
+	if rootParent.Valid ||
+		rootAuthor != "homeowner" ||
+		title != "Leaky sink" ||
+		rootBody != "It drips." ||
+		city != "Oakland" ||
+		postDate != "2026-08-26" ||
+		rootCreated != "2026-08-26T08:00:00Z" ||
+		rootUpdated != rootCreated {
+		t.Fatalf("unexpected root post")
+	}
+
+	var replyParent, replyAuthor, replyBody, replyCreated, replyUpdated string
+	if err := conn.QueryRowContext(ctx, `
+SELECT parent_id, author_id, body, created_at, updated_at
+FROM posts
+WHERE id = 'answer:question-1'`).Scan(
+		&replyParent,
+		&replyAuthor,
+		&replyBody,
+		&replyCreated,
+		&replyUpdated,
+	); err != nil {
+		t.Fatal(err)
+	}
+	if replyParent != "question-1" ||
+		replyAuthor != "plumber" ||
+		replyBody != "Replace the cartridge." ||
+		replyCreated != "2026-08-26T09:00:00Z" ||
+		replyUpdated != "2026-08-26T09:05:00Z" {
+		t.Fatalf("unexpected reply post")
+	}
+
+	var voteValue int
+	if err := conn.QueryRowContext(ctx, `
+SELECT value FROM post_votes
+WHERE user_id = 'homeowner' AND post_id = 'question-1'`).Scan(&voteValue); err != nil {
+		t.Fatal(err)
+	}
+	if voteValue != 1 {
+		t.Fatalf("vote value = %d, want 1", voteValue)
+	}
+
+	if _, err := conn.ExecContext(ctx, `
+INSERT INTO posts (
+  id, parent_id, author_id, title, body, city, post_date, hidden, created_at, updated_at
+) VALUES (
+  'invalid-reply', 'question-1', 'homeowner', 'Replies cannot have titles', 'Body', '', '', 0, 'now', 'now'
+)`); err == nil {
+		t.Fatal("reply with root-only title unexpectedly succeeded")
+	}
+}
+
+func TestMigratePostsReportsStep(t *testing.T) {
+	t.Parallel()
+
+	exec := &failingMigrationExec{failAt: 5}
+	err := migratePosts(context.Background(), exec)
+	if err == nil || !strings.Contains(err.Error(), "copy questions") {
+		t.Fatalf("error = %v, want copy questions context", err)
+	}
+}
+
+type failingMigrationExec struct {
+	calls  int
+	failAt int
+}
+
+func (f *failingMigrationExec) ExecContext(context.Context, string, ...any) (sql.Result, error) {
+	f.calls++
+	if f.calls == f.failAt {
+		return nil, fmt.Errorf("boom")
+	}
+	return nil, nil
+}
+
+func (*failingMigrationExec) QueryContext(context.Context, string, ...any) (*sql.Rows, error) {
+	return nil, fmt.Errorf("not implemented")
+}