Add framework for executing tests against multiple postgresql versions using docker compose.

tests/pgintegration/CMakeLists.txt

@@ -0,0 +1,21 @@
+add_library(pgintegration STATIC
+    PgTestEnvironment.h
+    PgTestEnvironment.cpp
+    DbTest.h
+    DbTest.cpp
+    )
+
+target_link_libraries(pgintegration PUBLIC
+    pgsql
+    GTest::gtest
+    Qt6::Core
+    )
+
+target_include_directories(pgintegration PUBLIC
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    )
+
+set_target_properties(pgintegration PROPERTIES
+    CXX_STANDARD 20
+    CXX_STANDARD_REQUIRED ON
+    )

tests/pgintegration/DbTest.cpp

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+#include "DbTest.h"
+#include "PgTestEnvironment.h"
+
+#include <atomic>
+#include <stdexcept>
+
+namespace pgtest {
+
+namespace {
+std::atomic<int> g_counter{0};
+}
+
+QString DbTest::dbUrl() const
+{
+    return urlForDb(dbName_);
+}
+
+void DbTest::SetUp()
+{
+    if (!available())
+        GTEST_SKIP() << "TEST_DATABASE_URL not set or template database unavailable";
+
+    dbName_ = QString("t_%1_%2").arg(g_counter++).arg(processId());
+    try {
+        {
+            Pgsql::Connection admin;
+            admin.connect(*baseUrl());
+            admin.query(QString("CREATE DATABASE %1 TEMPLATE %2")
+                        .arg(quoteIdent(dbName_), quoteIdent(templateDbName())));
+        }
+        conn_ = std::make_unique<Pgsql::Connection>();
+        conn_->connect(dbUrl());
+    }
+    catch (const std::exception &e) {
+        FAIL() << "Creating test database failed: " << e.what();
+    }
+}
+
+void DbTest::TearDown()
+{
+    conn_.reset();
+    if (dbName_.isEmpty())
+        return;
+    try {
+        Pgsql::Connection admin;
+        admin.connect(*baseUrl());
+        admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(dbName_)));
+    }
+    catch (const std::exception &e) {
+        ADD_FAILURE() << "Dropping test database failed: " << e.what();
+    }
+    dbName_.clear();
+}
+
+} // namespace pgtest

tests/pgintegration/DbTest.h

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+#pragma once
+
+#include <gtest/gtest.h>
+#include <memory>
+#include <QString>
+
+#include "Pgsql_Connection.h"
+
+namespace pgtest {
+
+/// Fixture giving every test its own database cloned from the template.
+class DbTest : public ::testing::Test {
+protected:
+    void SetUp() override;
+    void TearDown() override;
+
+    Pgsql::Connection& conn() { return *conn_; }
+    QString dbName() const { return dbName_; }
+    QString dbUrl() const;
+
+private:
+    QString dbName_;
+    std::unique_ptr<Pgsql::Connection> conn_;
+};
+
+} // namespace pgtest

tests/pgintegration/PgTestEnvironment.cpp

@@ -0,0 +1,125 @@
+#include "PgTestEnvironment.h"
+
+#include <QCoreApplication>
+#include <QFile>
+#include <QUrl>
+#include <iostream>
+#include <stdexcept>
+
+#include "Pgsql_Connection.h"
+#include "Pgsql_Result.h"
+
+namespace pgtest {
+
+namespace {
+
+bool g_available = false;
+int g_versionNum = 0;
+
+} // namespace
+
+std::optional<QString> baseUrl()
+{
+    QByteArray v = qgetenv("TEST_DATABASE_URL");
+    if (v.isEmpty())
+        return std::nullopt;
+    return QString::fromUtf8(v);
+}
+
+QString urlForDb(const QString &db)
+{
+    auto base = baseUrl();
+    if (!base)
+        throw std::runtime_error("TEST_DATABASE_URL is not set");
+    QUrl url(*base);
+    url.setPath("/" + db);
+    return url.toString();
+}
+
+bool available()
+{
+    return g_available;
+}
+
+int serverVersionNum()
+{
+    return g_versionNum;
+}
+
+qint64 processId()
+{
+    return QCoreApplication::applicationPid();
+}
+
+QString templateDbName()
+{
+    return QString("tmpl_%1").arg(processId());
+}
+
+QString quoteIdent(const QString &name)
+{
+    QString r = name;
+    r.replace('"', "\"\"");
+    return "\"" + r + "\"";
+}
+
+void PgEnv::SetUp()
+{
+    auto base = baseUrl();
+    if (!base) {
+        std::cerr << "TEST_DATABASE_URL not set, integration tests will be skipped\n";
+        return;
+    }
+
+    const QString tmpl = templateDbName();
+    try {
+        {
+            Pgsql::Connection admin;
+            admin.connect(*base);
+            Pgsql::Result r = admin.query("SHOW server_version_num");
+            if (!r || r.rows() != 1)
+                throw std::runtime_error("could not query server_version_num");
+            g_versionNum = QString::fromUtf8(r.val(0, 0)).toInt();
+            admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(tmpl)));
+            admin.query(QString("CREATE DATABASE %1").arg(quoteIdent(tmpl)));
+        }
+        {
+            QFile f(fixtureDir_ + "/schema.sql");
+            if (!f.open(QIODevice::ReadOnly))
+                throw std::runtime_error("cannot open " + f.fileName().toStdString());
+            QByteArray sql = f.readAll();
+
+            Pgsql::Connection c;
+            c.connect(urlForDb(tmpl));
+            c.query(sql.constData());
+        }
+        g_available = true;
+    }
+    catch (const std::exception &e) {
+        ADD_FAILURE() << "Setting up template database failed: " << e.what();
+        try {
+            Pgsql::Connection admin;
+            admin.connect(*base);
+            admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(tmpl)));
+        }
+        catch (const std::exception &) {
+        }
+    }
+}
+
+void PgEnv::TearDown()
+{
+    if (!g_available)
+        return;
+    try {
+        Pgsql::Connection admin;
+        admin.connect(*baseUrl());
+        admin.query(QString("DROP DATABASE IF EXISTS %1 WITH (FORCE)").arg(quoteIdent(templateDbName())));
+    }
+    catch (const std::exception &e) {
+        ADD_FAILURE() << "Dropping template database failed: " << e.what();
+    }
+    g_available = false;
+}
+
+} // namespace pgtest

tests/pgintegration/PgTestEnvironment.h

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+#pragma once
+
+#include <gtest/gtest.h>
+#include <optional>
+#include <QString>
+
+namespace pgtest {
+
+/// Value of the TEST_DATABASE_URL environment variable, if set and non-empty.
+std::optional<QString> baseUrl();
+
+/// Same as baseUrl() but with the database name replaced.
+QString urlForDb(const QString &db);
+
+/// True when a server is configured and the template database was created.
+bool available();
+
+/// server_version_num of the server under test (0 when unavailable).
+int serverVersionNum();
+
+/// Portable process id.
+qint64 processId();
+
+/// Name of the template database for this process.
+QString templateDbName();
+
+/// Quotes an identifier for use in SQL.
+QString quoteIdent(const QString &name);
+
+/// Global environment, register it in main():
+///   ::testing::AddGlobalTestEnvironment(new pgtest::PgEnv(PGTEST_FIXTURE_DIR));
+/// Creates a template database from <fixtureDir>/schema.sql once per process.
+class PgEnv : public ::testing::Environment {
+public:
+    explicit PgEnv(QString fixtureDir) : fixtureDir_(std::move(fixtureDir)) {}
+    void SetUp() override;
+    void TearDown() override;
+
+private:
+    QString fixtureDir_;
+};
+
+} // namespace pgtest
+
+#define REQUIRE_PG_AT_LEAST(v) \
+    if (pgtest::serverVersionNum() < (v) * 10000) GTEST_SKIP() << "needs PG " #v