| 1 | // SPDX-License-Identifier: AGPL-3.0-or-later |
| 2 | |
| 3 | // Package dbtest provides a parallel-safe test database harness. Each |
| 4 | // caller gets a freshly cloned database from a template that has all |
| 5 | // migrations applied. |
| 6 | // |
| 7 | // Usage: |
| 8 | // |
| 9 | // func TestSomething(t *testing.T) { |
| 10 | // pool := dbtest.NewTestDB(t) |
| 11 | // // pool is a *pgxpool.Pool against a freshly cloned DB. |
| 12 | // } |
| 13 | // |
| 14 | // The harness reads SHITHUB_TEST_DATABASE_URL for the bootstrap connection |
| 15 | // (used to CREATE/DROP databases). Tests are skipped if the env var is not |
| 16 | // set, so unit tests stay green on machines without Postgres. |
| 17 | package dbtest |
| 18 | |
| 19 | import ( |
| 20 | "context" |
| 21 | "crypto/rand" |
| 22 | "encoding/hex" |
| 23 | "fmt" |
| 24 | "net/url" |
| 25 | "os" |
| 26 | "sync" |
| 27 | "testing" |
| 28 | "time" |
| 29 | |
| 30 | "github.com/jackc/pgx/v5" |
| 31 | "github.com/jackc/pgx/v5/pgxpool" |
| 32 | |
| 33 | "github.com/tenseleyFlow/shithub/internal/infra/db" |
| 34 | _ "github.com/tenseleyFlow/shithub/internal/migrationsfs" // register migrations |
| 35 | ) |
| 36 | |
| 37 | const envURL = "SHITHUB_TEST_DATABASE_URL" |
| 38 | |
| 39 | var ( |
| 40 | templateOnce sync.Once |
| 41 | templateName string |
| 42 | templateError error |
| 43 | ) |
| 44 | |
| 45 | // NewTestDB returns a *pgxpool.Pool against a freshly created database |
| 46 | // cloned from the per-test-suite template. The database is dropped on |
| 47 | // t.Cleanup. Calls t.Skip if SHITHUB_TEST_DATABASE_URL is unset. |
| 48 | func NewTestDB(t *testing.T) *pgxpool.Pool { |
| 49 | t.Helper() |
| 50 | bootURL := os.Getenv(envURL) |
| 51 | if bootURL == "" { |
| 52 | t.Skipf("dbtest: %s not set; skipping integration test", envURL) |
| 53 | } |
| 54 | |
| 55 | templateOnce.Do(func() { |
| 56 | templateName, templateError = ensureTemplate(bootURL) |
| 57 | }) |
| 58 | if templateError != nil { |
| 59 | t.Fatalf("dbtest: template setup: %v", templateError) |
| 60 | } |
| 61 | |
| 62 | dbName := uniqueDBName() |
| 63 | if err := createFromTemplate(bootURL, dbName, templateName); err != nil { |
| 64 | t.Fatalf("dbtest: clone db: %v", err) |
| 65 | } |
| 66 | t.Cleanup(func() { |
| 67 | if err := dropDB(bootURL, dbName); err != nil { |
| 68 | t.Logf("dbtest: drop %s: %v", dbName, err) |
| 69 | } |
| 70 | }) |
| 71 | |
| 72 | pool, err := db.Open(context.Background(), db.Config{ |
| 73 | URL: replaceDBName(bootURL, dbName), |
| 74 | MaxConns: 4, |
| 75 | MinConns: 0, |
| 76 | }) |
| 77 | if err != nil { |
| 78 | t.Fatalf("dbtest: open clone: %v", err) |
| 79 | } |
| 80 | t.Cleanup(pool.Close) |
| 81 | return pool |
| 82 | } |
| 83 | |
| 84 | // ensureTemplate creates the template database (if absent) and applies all |
| 85 | // migrations to it. Idempotent: subsequent runs reuse the existing template. |
| 86 | func ensureTemplate(bootURL string) (string, error) { |
| 87 | const name = "shithub_test_template" |
| 88 | ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second) |
| 89 | defer cancel() |
| 90 | |
| 91 | exists, err := dbExists(ctx, bootURL, name) |
| 92 | if err != nil { |
| 93 | return "", err |
| 94 | } |
| 95 | if !exists { |
| 96 | if err := createDB(bootURL, name); err != nil { |
| 97 | return "", err |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | // Apply migrations to the template. |
| 102 | tplURL := replaceDBName(bootURL, name) |
| 103 | if err := db.Migrate(ctx, db.Config{URL: tplURL}, db.MigrateUp); err != nil { |
| 104 | return "", fmt.Errorf("dbtest: migrate template: %w", err) |
| 105 | } |
| 106 | |
| 107 | // Mark the database as a template so CREATE ... TEMPLATE works without |
| 108 | // requiring superuser. (PG allows a non-template database as TEMPLATE |
| 109 | // when no other connections exist; marking it explicitly is cleaner.) |
| 110 | if err := execBoot(bootURL, "ALTER DATABASE "+quoteIdent(name)+" IS_TEMPLATE TRUE"); err != nil { |
| 111 | // Some Postgres versions/configs reject this; tolerate. |
| 112 | _ = err |
| 113 | } |
| 114 | return name, nil |
| 115 | } |
| 116 | |
| 117 | func dbExists(ctx context.Context, bootURL, name string) (bool, error) { |
| 118 | conn, err := pgx.Connect(ctx, bootURL) |
| 119 | if err != nil { |
| 120 | return false, fmt.Errorf("dbtest: connect: %w", err) |
| 121 | } |
| 122 | defer func() { _ = conn.Close(ctx) }() |
| 123 | var exists bool |
| 124 | err = conn.QueryRow(ctx, "SELECT EXISTS (SELECT 1 FROM pg_database WHERE datname = $1)", name).Scan(&exists) |
| 125 | if err != nil { |
| 126 | return false, fmt.Errorf("dbtest: pg_database query: %w", err) |
| 127 | } |
| 128 | return exists, nil |
| 129 | } |
| 130 | |
| 131 | func createDB(bootURL, name string) error { |
| 132 | return execBoot(bootURL, "CREATE DATABASE "+quoteIdent(name)) |
| 133 | } |
| 134 | |
| 135 | func dropDB(bootURL, name string) error { |
| 136 | // Force-disconnect any leftover sessions; harmless if there are none. |
| 137 | _ = execBoot(bootURL, "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = "+quoteLiteral(name)) |
| 138 | return execBoot(bootURL, "DROP DATABASE IF EXISTS "+quoteIdent(name)) |
| 139 | } |
| 140 | |
| 141 | func createFromTemplate(bootURL, name, template string) error { |
| 142 | return execBoot(bootURL, "CREATE DATABASE "+quoteIdent(name)+" TEMPLATE "+quoteIdent(template)) |
| 143 | } |
| 144 | |
| 145 | func execBoot(bootURL, sql string) error { |
| 146 | ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second) |
| 147 | defer cancel() |
| 148 | conn, err := pgx.Connect(ctx, bootURL) |
| 149 | if err != nil { |
| 150 | return fmt.Errorf("dbtest: connect: %w", err) |
| 151 | } |
| 152 | defer func() { _ = conn.Close(ctx) }() |
| 153 | _, err = conn.Exec(ctx, sql) |
| 154 | if err != nil { |
| 155 | return fmt.Errorf("dbtest: %s: %w", sql, err) |
| 156 | } |
| 157 | return nil |
| 158 | } |
| 159 | |
| 160 | // replaceDBName rewrites the path component of a postgres URL to point at a |
| 161 | // different database. |
| 162 | func replaceDBName(bootURL, name string) string { |
| 163 | u, err := url.Parse(bootURL) |
| 164 | if err != nil { |
| 165 | return bootURL |
| 166 | } |
| 167 | u.Path = "/" + name |
| 168 | return u.String() |
| 169 | } |
| 170 | |
| 171 | // uniqueDBName returns a per-test-database name. Hex prefix avoids clashes |
| 172 | // across parallel test runs. |
| 173 | func uniqueDBName() string { |
| 174 | var b [6]byte |
| 175 | _, _ = rand.Read(b[:]) |
| 176 | return "shithub_test_" + hex.EncodeToString(b[:]) |
| 177 | } |
| 178 | |
| 179 | // quoteIdent wraps an identifier in double quotes and escapes any embedded |
| 180 | // double quotes. For test-DB names we generate the names ourselves so this |
| 181 | // is purely belt-and-braces. |
| 182 | func quoteIdent(s string) string { |
| 183 | out := make([]byte, 0, len(s)+2) |
| 184 | out = append(out, '"') |
| 185 | for i := 0; i < len(s); i++ { |
| 186 | if s[i] == '"' { |
| 187 | out = append(out, '"') |
| 188 | } |
| 189 | out = append(out, s[i]) |
| 190 | } |
| 191 | out = append(out, '"') |
| 192 | return string(out) |
| 193 | } |
| 194 | |
| 195 | func quoteLiteral(s string) string { |
| 196 | out := make([]byte, 0, len(s)+2) |
| 197 | out = append(out, '\'') |
| 198 | for i := 0; i < len(s); i++ { |
| 199 | if s[i] == '\'' { |
| 200 | out = append(out, '\'') |
| 201 | } |
| 202 | out = append(out, s[i]) |
| 203 | } |
| 204 | out = append(out, '\'') |
| 205 | return string(out) |
| 206 | } |
| 207 |