fix: make user signup work for the minimum

A lot of work is still to be done ...

.gitignore

@@ -25,3 +25,4 @@ go.work.sum
 # Custom
 /_output
 /deployment/db_data
+/tmp/**

Makefile

@@ -33,9 +33,12 @@ all: add-copyright format build
 # ==============================================================================
 
 .PHONY: build
-build: tidy # build.
+build: tidy sqlc # build.
 	@go build -v -ldflags "$(GO_LDFLAGS)" -o $(OUTPUT_DIR)/howmuch $(ROOT_DIR)/cmd/howmuch/main.go 2>/dev/null
 
+.PHONY: sqlc
+	@sqlc generate
+
 .PHONY: format
 format: # format code.
 	@gofmt -s -w ./

README.md

@@ -198,9 +198,46 @@ type User struct {
 
 Use Buffalo pop `Soda CLI` to create database migrations.
 
-### 2024/10/07
+### 2024/10/06
 
 Implement the architecture design for User entity.
 
 Checked out OpenAPI, and found that it was not that simple at all. It needs
 a whole package of knowledge about the web development!
+
+For the test-driven part,
+
+- model layer: just model designs, **nothing to test**
+- infra: routes and db connections, it works when it works. Nothing to test.
+- registry: Just return some structs, no logic. **Not worth testing**
+- adapter:
+    - input-port (controller) test: it is about testing parsing the input
+    value, and the output results writing. The unit test of controller is to
+    **make sure that they behave as defined in the API documentation**. To
+    test, we have to mock the **business service**.
+    - output-port (repo) test: it is about testing converting business model
+    to database model and the interaction with the database. If we are going
+    to test them, it's about simulating different type of database behaviour
+    (success, timeout, etc.). To test, we have to mock the
+    **database connection**.
+- usecase: This is the core part to test, it's about the core business.
+We provide the data input and we check the data output in a fake repository.
+
+With this design, although it may seem overkill for this little project, fits
+perfectly well with the TDD method.
+
+Concretely, I will do the TDD for my usecase level development, and for the
+rest, I just put unit tests aside for later.
+
+#### Workflow
+
+1. OAS Definition
+2. (Integration/Validation test)
+3. Usecase unit test cases
+4. Usecase development
+5. Refactor (2-3-4)
+6. Input-port/Output-port
+
+That should be the correct workflow. But to save time, I will cut off the
+integration test part (the 2nd point).
+

api/openapi/openapi.yaml

@@ -39,7 +39,7 @@ tags:
   - name: user
 
 paths:
-  /signup:
+  /user/signup:
     post:
       tags:
         - user

docs/error_code.md

@@ -0,0 +1,7 @@
+# Platform level error code design
+
+- InternalError
+- InvalidParameter
+- AuthFailure
+- ResourceNotFound
+- FailedOperation

go.mod

@@ -35,7 +35,6 @@ require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
-	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.7 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
@@ -61,7 +60,6 @@ require (
 	golang.org/x/arch v0.8.0 // indirect
 	golang.org/x/crypto v0.27.0 // indirect
 	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
-	golang.org/x/sync v0.8.0 // indirect
 	golang.org/x/sys v0.25.0 // indirect
 	golang.org/x/text v0.18.0 // indirect
 	google.golang.org/protobuf v1.34.1 // indirect

internal/howmuch/adapter/controller/user.go

@@ -25,33 +25,66 @@ package controller
 import (
 	"net/http"
 
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/usecase"
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/core"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/errno"
+	"github.com/gin-gonic/gin"
 )
 
 // User is the user controller interface, it describes all the handlers
 // that need to be implemented for the /user endpoint
 type User interface {
 	Signup(core.Context)
-	UpdateInfo(core.Context)
-	Login(core.Context)
-	Logout(core.Context)
-	ChangePassword(core.Context)
+	UpdateInfo(*gin.Context)
+	Login(*gin.Context)
+	Logout(*gin.Context)
+	ChangePassword(*gin.Context)
 }
 
-type UserController struct{}
+type UserController struct {
+	userUsecase usecase.User
+}
+
+var UserParamsErr = &errno.Errno{
+	HTTP:    http.StatusBadRequest,
+	Code:    errno.ErrorCode(errno.InvalidParameterCode, "UserParamsErr"),
+	Message: "user info is not correct",
+}
+
+func NewUserController(us usecase.User) User {
+	return &UserController{
+		userUsecase: us,
+	}
+}
 
 func (uc *UserController) Signup(ctx core.Context) {
-	ctx.JSON(http.StatusOK, "hello")
+	var params model.User
+
+	if err := ctx.Bind(&params); err != nil {
+		core.WriteResponse(ctx, UserParamsErr, nil)
+		return
 	}
 
-func (uc *UserController) UpdateInfo(ctx core.Context) {
+	// TODO: check params validity (govalidator)
+
+	_, err := uc.userUsecase.Create(ctx, &params)
+	if err != nil {
+		core.WriteResponse(ctx, err, nil)
+		return
 	}
 
-func (uc *UserController) Login(ctx core.Context) {
+	core.WriteResponse(ctx, errno.OK, nil)
 }
 
-func (uc *UserController) Logout(ctx core.Context) {
+func (uc *UserController) UpdateInfo(ctx *gin.Context) {
 }
 
-func (uc *UserController) ChangePassword(ctx core.Context) {
+func (uc *UserController) Login(ctx *gin.Context) {
+}
+
+func (uc *UserController) Logout(ctx *gin.Context) {
+}
+
+func (uc *UserController) ChangePassword(ctx *gin.Context) {
 }

internal/howmuch/adapter/repo/db.go

@@ -0,0 +1,68 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+	"github.com/jackc/pgx/v5"
+)
+
+type dbRepository struct {
+	db *pgx.Conn
+}
+
+func NewDBRepository(db *pgx.Conn) repo.DBRepository {
+	return &dbRepository{
+		db: db,
+	}
+}
+
+// XXX: Do I need rollback? in which cases?
+
+func (dr *dbRepository) Transaction(
+	ctx context.Context,
+	txFunc func(txCtx context.Context, tx interface{}) (interface{}, error),
+) (interface{}, error) {
+	tx, err := dr.db.Begin(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if p := recover(); p != nil {
+			tx.Rollback(ctx)
+			log.PanicLog("transaction panicked!")
+		} else if err != nil {
+			tx.Rollback(ctx)
+			log.ErrorLog("transaction failed!", "err", err)
+		} else {
+			err = tx.Commit(ctx)
+		}
+	}()
+
+	data, err := txFunc(ctx, tx)
+	return data, err
+}

internal/howmuch/adapter/repo/user.go

@@ -0,0 +1,88 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo/sqlc"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+type userRepository struct {
+	db *pgx.Conn
+}
+
+const insertTimeout = 1 * time.Second
+
+func NewUserRepository(db *pgx.Conn) repo.UserRepository {
+	return &userRepository{
+		db: db,
+	}
+}
+
+// Create
+func (ur *userRepository) Create(
+	ctx context.Context,
+	transaction interface{},
+	u *model.User,
+) (*model.User, error) {
+	timeoutCtx, cancel := context.WithTimeout(ctx, insertTimeout)
+	defer cancel()
+
+	args := sqlc.InsertUserParams{
+		Email:     u.Email,
+		FirstName: u.FirstName,
+		LastName:  u.LastName,
+		Password:  u.Password,
+		CreatedAt: pgtype.Timestamp{Time: time.Now(), Valid: true},
+		UpdatedAt: pgtype.Timestamp{Time: time.Now(), Valid: true},
+	}
+
+	tx, ok := transaction.(pgx.Tx)
+	if !ok {
+		return nil, errors.New("transaction is not a pgx.Tx")
+	}
+
+	queries := sqlc.New(tx)
+
+	userDB, err := queries.InsertUser(timeoutCtx, args)
+	if err != nil {
+		return nil, err
+	}
+
+	return &model.User{
+		ID:        int(userDB.ID),
+		Email:     userDB.Email,
+		FirstName: userDB.FirstName,
+		LastName:  userDB.LastName,
+		Password:  userDB.Password,
+		CreatedAt: userDB.CreatedAt.Time,
+		UpdatedAt: userDB.CreatedAt.Time,
+	}, nil
+}

internal/howmuch/howmuch.go

@@ -37,6 +37,7 @@ import (
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
 	"git.vinchent.xyz/vinchent/howmuch/pkg/version/verflag"
 	"github.com/gin-gonic/gin"
+	"github.com/jackc/pgx/v5"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"golang.org/x/net/context"
@@ -105,8 +106,7 @@ func run() error {
 	}
 
 	// Init DB
-	dbPool, err := datastore.NewDB(
-		fmt.Sprintf(
+	dbConfString := fmt.Sprintf(
 		"host=%s port=%d dbname=%s user=%s password=%s sslmode=%s",
 		viper.GetString("db.host"),
 		viper.GetInt("db.port"),
@@ -114,15 +114,19 @@ func run() error {
 		viper.GetString("db.username"),
 		viper.GetString("db.password"),
 		viper.GetString("db.sslmode"),
-		),
 	)
+	dbConf, err := pgx.ParseConfig(dbConfString)
+	if err != nil {
+		log.FatalLog("DB connection config failure", "err", err, "cfg string", dbConfString)
+	}
+	dbConn, err := datastore.NewDB(dbConf)
 	if err != nil {
 		log.FatalLog("DB connection failure", "err", err)
 	}
-	defer dbPool.Close()
+	defer dbConn.Close(context.Background())
 
 	// Register the core service
-	r := registry.NewRegistry(dbPool)
+	r := registry.NewRegistry(dbConn)
 
 	engine := gin.Default()
 

internal/howmuch/infra/datastore/db.go

@@ -25,12 +25,12 @@ package datastore
 import (
 	"context"
 
-	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/jackc/pgx/v5"
 )
 
 // NewDB creates a new database for the application
-func NewDB(dsn string) (*pgxpool.Pool, error) {
-	conn, err := pgxpool.New(context.Background(), dsn)
+func NewDB(connConfig *pgx.ConnConfig) (*pgx.Conn, error) {
+	conn, err := pgx.ConnectConfig(context.Background(), connConfig)
 	if err != nil {
 		return nil, err
 	}

internal/howmuch/infra/router/router.go

@@ -48,7 +48,13 @@ func Routes(engine *gin.Engine, c controller.AppController) *gin.Engine {
 		core.WriteResponse(ctx, errno.PageNotFoundErr, nil)
 	})
 
-	engine.POST("/signup", func(ctx *gin.Context) { c.User.Signup(ctx) })
+	v1 := engine.Group("/v1")
+	{
+		userV1 := v1.Group("/user")
+		{
+			userV1.POST("/signup", func(ctx *gin.Context) { c.User.Signup(ctx) })
+		}
+	}
 
 	return engine
 }

internal/howmuch/model/user.go

@@ -0,0 +1,36 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package model
+
+import "time"
+
+// User model
+type User struct {
+	ID        int       `json:"id"`
+	Email     string    `json:"email"`
+	FirstName string    `json:"first_name"`
+	LastName  string    `json:"last_name"`
+	Password  string    `json:"password"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}

internal/howmuch/registry/registry.go

@@ -24,7 +24,7 @@ package registry
 
 import (
 	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/controller"
-	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/jackc/pgx/v5"
 )
 
 // registry is an implementation of Registry interface.
@@ -32,7 +32,7 @@ import (
 // It might holds other drivers when the projects grows. For example
 // the object needed to connect to Redis or Kafka.
 type registry struct {
-	db *pgxpool.Pool
+	db *pgx.Conn
 }
 
 // Registry returns a new app controller that will be used by main()/run()
@@ -43,7 +43,7 @@ type Registry interface {
 }
 
 // NewRegistry returns a new Registry's implementation.
-func NewRegistry(db *pgxpool.Pool) Registry {
+func NewRegistry(db *pgx.Conn) Registry {
 	return &registry{db: db}
 }
 

internal/howmuch/registry/user.go

@@ -22,9 +22,14 @@
 
 package registry
 
-import "git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/controller"
+import (
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/controller"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/adapter/repo"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/usecase"
+)
 
 // NewUserController returns a user controller's implementation
 func (r *registry) NewUserController() controller.User {
-	return &controller.UserController{}
+	u := usecase.NewUserUsecase(repo.NewUserRepository(r.db), repo.NewDBRepository(r.db))
+	return controller.NewUserController(u)
 }

internal/howmuch/usecase/repo/db.go

@@ -0,0 +1,32 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import "context"
+
+type DBRepository interface {
+	Transaction(
+		ctx context.Context,
+		txFunc func(txCtx context.Context, tx interface{}) (interface{}, error),
+	) (interface{}, error)
+}

internal/howmuch/usecase/repo/testdb.go

@@ -0,0 +1,34 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import "context"
+
+type TestDBRepository struct{}
+
+func (tdr *TestDBRepository) Transaction(
+	ctx context.Context,
+	txFunc func(txCtx context.Context, tx interface{}) (interface{}, error),
+) (interface{}, error) {
+	return txFunc(ctx, nil)
+}

internal/howmuch/usecase/repo/testuser.go

@@ -0,0 +1,42 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+)
+
+type TestUserRepository struct{}
+
+func (tur *TestUserRepository) Create(
+	ctx context.Context,
+	transaction interface{},
+	u *model.User,
+) (*model.User, error) {
+	user := *u
+
+	user.ID = 123
+	return &user, nil
+}

internal/howmuch/usecase/repo/user.go

@@ -0,0 +1,33 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package repo
+
+import (
+	"context"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+)
+
+type UserRepository interface {
+	Create(ctx context.Context, transaction interface{}, u *model.User) (*model.User, error)
+}

internal/howmuch/usecase/usecase/user.go

@@ -0,0 +1,78 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package usecase
+
+import (
+	"context"
+	"fmt"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+)
+
+type userUsecase struct {
+	userRepo repo.UserRepository
+	dbRepo   repo.DBRepository
+}
+
+type User interface {
+	Create(ctx context.Context, u *model.User) (*model.User, error)
+}
+
+func NewUserUsecase(r repo.UserRepository, d repo.DBRepository) User {
+	return &userUsecase{
+		userRepo: r,
+		dbRepo:   d,
+	}
+}
+
+func (uuc *userUsecase) Create(ctx context.Context, u *model.User) (*model.User, error) {
+	data, err := uuc.dbRepo.Transaction(
+		ctx,
+		func(txCtx context.Context, tx interface{}) (interface{}, error) {
+			u, err := uuc.userRepo.Create(txCtx, tx, u)
+			if err != nil {
+				return nil, err
+			}
+
+			// TODO: App log, maybe can be sent to some third party service.
+			log.InfoLog(
+				"created new user",
+				"email",
+				u.Email,
+				"name",
+				fmt.Sprintf("%s %s", u.FirstName, u.LastName),
+			)
+
+			return u, err
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	user := data.(*model.User)
+
+	return user, nil
+}

internal/howmuch/usecase/usecase/user_test.go

@@ -0,0 +1,49 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package usecase
+
+import (
+	"context"
+	"testing"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/model"
+	"git.vinchent.xyz/vinchent/howmuch/internal/howmuch/usecase/repo"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCreateUser(t *testing.T) {
+	ctx := context.Background()
+	userUsecase := NewUserUsecase(&repo.TestUserRepository{}, &repo.TestDBRepository{})
+	input := &model.User{
+		Email:     "a@b.c",
+		FirstName: "James",
+		LastName:  "Bond",
+		Password:  "verystrong",
+	}
+	want := input
+	want.ID = 123
+
+	got, err := userUsecase.Create(ctx, input)
+	assert.NoError(t, err)
+	assert.Equal(t, want, got)
+}

internal/pkg/core/context.go

@@ -22,6 +22,18 @@
 
 package core
 
+import "time"
+
 type Context interface {
+	// Context
+	Deadline() (deadline time.Time, ok bool)
+	Done() <-chan struct{}
+	Err() error
+	Value(key any) any
+
+	// Request
+	Bind(obj any) error
+
+	// Response
 	JSON(code int, obj any)
 }

internal/pkg/errno/code.go

@@ -24,18 +24,28 @@ package errno
 
 import "net/http"
 
+type PlatformLevelErrCode string
+
+const (
+	InternalErrorCode    = "InternalError"
+	InvalidParameterCode = "InvalidParameter"
+	AuthFailureCode      = "AuthFailure"
+	ResourceNotFoundCode = "ResourceNotFound"
+	FailedOperationCode  = "FailedOperation"
+)
+
 var (
 	OK = &Errno{HTTP: http.StatusOK, Code: "", Message: ""}
 
 	InternalServerErr = &Errno{
 		HTTP:    http.StatusInternalServerError,
-		Code:    "InternalError",
+		Code:    InternalErrorCode,
 		Message: "Internal server error",
 	}
 
 	PageNotFoundErr = &Errno{
 		HTTP:    http.StatusNotFound,
-		Code:    "ResourceNotFound.PageNotFound",
+		Code:    ErrorCode(ResourceNotFoundCode, "PageNotFound"),
 		Message: "Page not found",
 	}
 )

internal/pkg/errno/errno.go

@@ -28,6 +28,10 @@ type Errno struct {
 	Message string
 }
 
+func ErrorCode(platformErrCode string, resourceErrCode string) string {
+	return platformErrCode + "." + resourceErrCode
+}
+
 // Error implements Error() method in error interface
 func (err *Errno) Error() string {
 	return err.Message

migrations/20241006114157_admin_table_add_constraint.postgres.up.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "admin"
+ADD CONSTRAINT unique_email UNIQUE ("email");

sqlc.yml

@@ -23,9 +23,9 @@
 version: "2"
 sql:
   - engine: "postgresql"
-    queries: "internal/app/adapter/repo/sqlc"
+    queries: "internal/howmuch/adapter/repo/sqlc"
     schema: "migrations"
     gen:
       go:
-        out: "internal/app/controller/repo/sqlc"
+        out: "internal/howmuch/adapter/repo/sqlc"
         sql_package: "pgx/v5"

tmp/build-errors.log

@@ -1 +0,0 @@
-exit status 2exit status 2exit status 2exit status 2exit status 2