Publish an example testing go code with Postgres

2024-12-24 16:28:34 +02:00 · 2023-07-05 01:31:59 +03:00 · 2023-07-05 01:31:59 +03:00 · b346272f7f
commit b346272f7f
parent 7e6770223e
15 changed files with 559 additions and 0 deletions
--- a/.editorconfig
+++ b/.editorconfig
@ -0,0 +1,16 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+max_line_length = 100
+tab_width = 4
+
+[Makefile]
+indent_style = tab
+
+[*.go]
+indent_style = tab
--- a/.gitignore
+++ b/.gitignore
@ -0,0 +1 @@
+/coverage.out
--- a/52
+++ b/52
@ -0,0 +1,52 @@
+.DEFAULT_GOAL := help
+
+COVER_FILE ?= coverage.out
+
+.PHONY: build
+build: ## Build a command to quickly check compiles.
+	@go build ./...
+
+.PHONY: check
+check: lint build test ## Runs all necessary code checks.
+
+.PHONY: test
+test: ## Run all tests.
+	@go test -race -count=1 -coverprofile=$(COVER_FILE) ./...
+	@go tool cover -func=$(COVER_FILE) | grep ^total | tr -s '\t'
+
+.PHONY: test-short
+test-short: ## Run only unit tests, tests without I/O dependencies.
+	@go test -short ./...
+
+.PHONY: test-env-up
+test-env-up: ## Run test environment.
+	@docker-compose up migrate
+
+.PHONY: test-env-down
+test-env-down: ## Down and cleanup test environment.
+	@docker-compose down -v
+
+.PHONY: lint
+lint: tools ## Check the project with lint.
+	@golangci-lint run \
+  --fix \
+  --disable-all \
+  -E errcheck \
+  -E godot \
+  -E goimports \
+  -E gosimple \
+  -E govet \
+  -E ineffassign \
+  -E misspell \
+  -E staticcheck \
+  -E typecheck \
+  -E unused \
+  -E whitespace \
+  ./...
+
+tools: ## Install all needed tools, e.g.
+	@go install -v github.com/golangci/golangci-lint/cmd/golangci-lint@v1.53.2
+
+.PHONY: help
+help: ## Show help for each of the Makefile targets.
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
--- a/README.md
+++ b/README.md
@ -0,0 +1,13 @@
+# Example of testing Go code with Postgres
+
+The example suggests a solution to the problem of cleaning the database after
+running tests and the problem of running tests in parallel. It also shows how
+to organize integration testing of Go code with Postgres.
+
+## How to use
+
+Run `make test-env-up test` and then everything will happen by itself.
+
+## Disclaimer
+
+**This example is not an example of software architecture!**
--- a/docker-compose.yml
+++ b/docker-compose.yml
@ -0,0 +1,30 @@
+version: "3.8"
+
+services:
+  postgres:
+    image: postgres:15.3-alpine3.18
+    environment:
+      POSTGRES_DB: postgres
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_USER: postgres
+      POSTGRES_MULTIPLE_DATABASES: reference
+    healthcheck:
+      test: pg_isready --username "postgres" --dbname "reference"
+      interval: 1s
+      retries: 5
+      timeout: 5s
+    ports:
+      - "32260:5432"
+    volumes:
+      - ./docker-multiple-databases.sh:/docker-entrypoint-initdb.d/docker-multiple-databases.sh:ro
+
+  migrate:
+    image: migrate/migrate:v4.16.2
+    command: > 
+      -source 'file:///migrations'
+      -database 'postgresql://postgres:postgres@postgres:5432/reference?sslmode=disable' up
+    depends_on:
+      postgres:
+        condition: service_healthy
+    volumes:
+      - ./migrations:/migrations:ro
--- a/docker-multiple-databases.sh
+++ b/docker-multiple-databases.sh
@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -e
+set -u
+
+function create_user_and_database() {
+  local database=$1
+  echo "  Creating user and database '$database'"
+  psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" <<-EOSQL
+      CREATE DATABASE $database OWNER $POSTGRES_USER;
+EOSQL
+}
+
+if [ -n "$POSTGRES_MULTIPLE_DATABASES" ]; then
+  echo "Multiple database creation requested: $POSTGRES_MULTIPLE_DATABASES"
+  for database in $(echo "$POSTGRES_MULTIPLE_DATABASES" | tr ',' ' '); do
+    create_user_and_database "$database"
+  done
+  echo "Multiple databases created"
+fi
--- a/go.mod
+++ b/go.mod
@ -0,0 +1,23 @@
+module github.com/xorcare/testing-go-code-with-postgres
+
+go 1.20
+
+require (
+	github.com/google/uuid v1.3.0
+	github.com/jackc/pgx/v5 v5.3.1
+	github.com/stretchr/testify v1.8.4
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
+	github.com/jackc/puddle/v2 v2.2.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/rogpeppe/go-internal v1.10.0 // indirect
+	golang.org/x/crypto v0.9.0 // indirect
+	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/text v0.9.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
--- a/go.sum
+++ b/go.sum
@ -0,0 +1,37 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a h1:bbPeKD0xmW/Y25WS6cokEszi5g+S0QxI/d45PkRi7Nk=
+github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.3.1 h1:Fcr8QJ1ZeLi5zsPZqQeUZhNhxfkkKBOgJuYkJHoBOtU=
+github.com/jackc/pgx/v5 v5.3.1/go.mod h1:t3JDKnCBlYIc0ewLF0Q7B8MXmoIaBOZj/ic7iHozM/8=
+github.com/jackc/puddle/v2 v2.2.0 h1:RdcDk92EJBuBS55nQMMYFXTxwstHug4jkhT5pq8VxPk=
+github.com/jackc/puddle/v2 v2.2.0/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
+github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/crypto v0.9.0 h1:LF6fAI+IutBocDJ2OT0Q1g8plpYljMZ4+lty+dsqw3g=
+golang.org/x/crypto v0.9.0/go.mod h1:yrmDGqONDYtNj3tH8X9dzUun2m2lzPa9ngI6/RUPGR0=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/text v0.9.0 h1:2sjJmO8cDvYveuX97RDLsxlyUxLl+GHoLxBiRdHllBE=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
--- a/migrations/000001_create_users_table.down.sql
+++ b/migrations/000001_create_users_table.down.sql
@ -0,0 +1 @@
+DROP TABLE users;
--- a/migrations/000001_create_users_table.up.sql
+++ b/migrations/000001_create_users_table.up.sql
@ -0,0 +1,6 @@
+CREATE TABLE users
+(
+    user_id    uuid,
+    username   VARCHAR(50) UNIQUE       NOT NULL,
+    created_at TIMESTAMP WITH TIME ZONE NOT NULL
+);
--- a/testingpg/testingpg.go
+++ b/testingpg/testingpg.go
@ -0,0 +1,116 @@
+// Copyright (c) 2023 Vasiliy Vasilyuk. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testingpg
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"os"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/stretchr/testify/require"
+)
+
+type TestingT interface {
+	require.TestingT
+
+	Logf(format string, args ...any)
+	Cleanup(f func())
+}
+
+func New(t TestingT) *Postgres {
+	return newPostgres(t).cloneFromReference(t)
+}
+
+type Postgres struct {
+	url string
+	ref string
+
+	conn *pgxpool.Pool
+}
+
+func newPostgres(t TestingT) *Postgres {
+	urlStr := os.Getenv("TESTING_DB_URL")
+	if urlStr == "" {
+		urlStr = "postgresql://postgres:postgres@localhost:32260/postgres?sslmode=disable"
+		const format = "env TESTING_DB_URL is empty, used default value: %s"
+		t.Logf(format, urlStr)
+	}
+
+	refDatabase := os.Getenv("TESTING_DB_REF")
+	if refDatabase == "" {
+		refDatabase = "reference"
+	}
+
+	pool, err := pgxpool.New(context.Background(), urlStr)
+	require.NoError(t, err)
+
+	return &Postgres{
+		url: urlStr,
+		ref: refDatabase,
+
+		conn: pool,
+	}
+}
+
+func (p *Postgres) URL() string {
+	return p.url
+}
+
+func (p *Postgres) PgxPool() *pgxpool.Pool {
+	return p.conn
+}
+
+func (p *Postgres) cloneFromReference(t TestingT) *Postgres {
+	cfg, err := pgxpool.ParseConfig(p.url)
+	require.NoError(t, err)
+
+	pool, err := pgxpool.New(context.Background(), p.url)
+	require.NoError(t, err)
+
+	newDatabaseName := uuid.New().String()
+
+	const sqlTemplate = `CREATE DATABASE %q WITH TEMPLATE %s OWNER %s;`
+	sql := fmt.Sprintf(
+		sqlTemplate,
+		newDatabaseName,
+		p.ref,
+		cfg.ConnConfig.User,
+	)
+	_, err = pool.Exec(context.Background(), sql)
+	require.NoError(t, err)
+
+	// Automatically drop database copy after the test is completed.
+	t.Cleanup(func() {
+		sql := fmt.Sprintf(`DROP DATABASE %q WITH (FORCE);`, newDatabaseName)
+
+		ctx, done := context.WithTimeout(context.Background(), time.Minute)
+		defer done()
+
+		_, err := p.conn.Exec(ctx, sql)
+		require.NoError(t, err)
+	})
+
+	urlString := replaceDBName(t, cfg, newDatabaseName)
+	newPool, err := pgxpool.New(context.Background(), urlString)
+	require.NoError(t, err)
+
+	return &Postgres{
+		url: urlString,
+		ref: newDatabaseName,
+
+		conn: newPool,
+	}
+}
+
+func replaceDBName(t TestingT, cfg *pgxpool.Config, dbname string) string {
+	r, err := url.Parse(cfg.ConnString())
+	require.NoError(t, err)
+	r.Path = dbname
+	return r.String()
+}
--- a/testingpg/testingpg_test.go
+++ b/testingpg/testingpg_test.go
@ -0,0 +1,95 @@
+// Copyright (c) 2023 Vasiliy Vasilyuk. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testingpg_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/stretchr/testify/require"
+
+	"github.com/xorcare/testing-go-code-with-postgres/testingpg"
+)
+
+func TestNewPostgres(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
+	t.Parallel()
+
+	t.Run("Successfully connect by URL and get version", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres := testingpg.New(t)
+
+		ctx := context.Background()
+		dbPool, err := pgxpool.New(ctx, postgres.URL())
+		require.NoError(t, err)
+
+		// Act
+		var version string
+		err = dbPool.QueryRow(ctx, "SELECT version();").Scan(&version)
+
+		// Assert
+		require.NoError(t, err)
+		require.NotEmpty(t, version)
+		t.Log(version)
+	})
+
+	t.Run("Successfully obtained a version using a pre-configured conn", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres := testingpg.New(t)
+		ctx := context.Background()
+
+		// Act
+		var version string
+		err := postgres.PgxPool().QueryRow(ctx, "SELECT version();").Scan(&version)
+
+		// Assert
+		require.NoError(t, err)
+		require.NotEmpty(t, version)
+
+		t.Log(version)
+	})
+
+	t.Run("Changes are not visible in different instances", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres1 := testingpg.New(t)
+		postgres2 := testingpg.New(t)
+
+		ctx := context.Background()
+
+		// Act
+		const sql = `CREATE TABLE "no_conflict" (id integer PRIMARY KEY)`
+		_, err1 := postgres1.PgxPool().Exec(ctx, sql)
+		_, err2 := postgres2.PgxPool().Exec(ctx, sql)
+
+		// Assert
+		require.NoError(t, err1)
+		require.NoError(t, err2, "databases must be isolated for each instance")
+	})
+
+	t.Run("URL is different at different instances", func(t *testing.T) {
+		t.Parallel()
+
+		// Arrange
+		postgres1 := testingpg.New(t)
+		postgres2 := testingpg.New(t)
+
+		// Act
+		url1 := postgres1.URL()
+		url2 := postgres2.URL()
+
+		// Assert
+		require.NotEqual(t, url1, url2)
+	})
+}
--- a/user_model.go
+++ b/user_model.go
@ -0,0 +1,17 @@
+// Copyright (c) 2023 Vasiliy Vasilyuk. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testing_go_code_with_postgres
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type User struct {
+	ID        uuid.UUID
+	Username  string
+	CreatedAt time.Time
+}
--- a/user_repository.go
+++ b/user_repository.go
@ -0,0 +1,55 @@
+// Copyright (c) 2023 Vasiliy Vasilyuk. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testing_go_code_with_postgres
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func NewUserRepository(db *pgxpool.Pool) *UserRepository {
+	return &UserRepository{db: db}
+}
+
+type UserRepository struct {
+	db *pgxpool.Pool
+}
+
+func (r *UserRepository) ReadUser(ctx context.Context, userID uuid.UUID) (User, error) {
+	const sql = `SELECT user_id, username, created_at FROM users WHERE user_id = $1;`
+
+	user := User{}
+
+	row := r.db.QueryRow(ctx, sql, userID)
+	err := row.Scan(&user.ID, &user.Username, &user.CreatedAt)
+	if err != nil {
+		const format = "failed selection of User from database: %v"
+		return User{}, fmt.Errorf(format, err)
+	}
+
+	return user, nil
+}
+
+func (r *UserRepository) CreateUser(ctx context.Context, user User) error {
+	const sql = `INSERT INTO users (user_id, username, created_at) VALUES ($1,$2,$3);`
+
+	_, err := r.db.Exec(
+		ctx,
+		sql,
+		user.ID,
+		user.Username,
+		user.CreatedAt,
+	)
+
+	if err != nil {
+		const format = "failed insertion of User to database: %v"
+		return fmt.Errorf(format, err)
+	}
+
+	return nil
+}
--- a/user_repository_test.go
+++ b/user_repository_test.go
@ -0,0 +1,77 @@
+// Copyright (c) 2023 Vasiliy Vasilyuk. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testing_go_code_with_postgres
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+
+	"github.com/xorcare/testing-go-code-with-postgres/testingpg"
+)
+
+func TestUserRepository_CreateUser(t *testing.T) {
+	newFullyFiledUser := func() User {
+		return User{
+			ID:        uuid.New(),
+			Username:  "gopher",
+			CreatedAt: time.Now().Truncate(time.Microsecond),
+		}
+	}
+
+	t.Run("Successfully created a User", func(t *testing.T) {
+		// Arrange
+		postgres := testingpg.New(t)
+		repo := NewUserRepository(postgres.PgxPool())
+
+		user := newFullyFiledUser()
+
+		// Act
+		err := repo.CreateUser(context.Background(), user)
+
+		// Assert
+		require.NoError(t, err)
+
+		gotUser, err := repo.ReadUser(context.Background(), user.ID)
+		require.NoError(t, err)
+
+		require.Equal(t, user, gotUser)
+	})
+
+	t.Run("Cannot create a user with the same ID", func(t *testing.T) {
+		// Arrange
+		postgres := testingpg.New(t)
+		repo := NewUserRepository(postgres.PgxPool())
+
+		user := newFullyFiledUser()
+
+		err := repo.CreateUser(context.Background(), user)
+		require.NoError(t, err)
+
+		// Act
+		err = repo.CreateUser(context.Background(), user)
+
+		// Assert
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "duplicate key value violates unique constraint")
+	})
+}
+
+func TestUserRepository_ReadUser(t *testing.T) {
+	t.Run("Get an error if the user does not exist", func(t *testing.T) {
+		// Arrange
+		postgres := testingpg.New(t)
+		repo := NewUserRepository(postgres.PgxPool())
+
+		// Act
+		_, err := repo.ReadUser(context.Background(), uuid.New())
+
+		// Assert
+		require.Error(t, err)
+	})
+}