examples_test.go

package espresso_test

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"os"

	"github.com/googollee/go-espresso"
)

func ExampleEspresso() {
	type Book struct {
		ID    int    `json:"id"`
		Title string `json:"title"`
	}
	type Books map[int]Book

	books := make(Books)
	books[1] = Book{
		ID:    1,
		Title: "The Espresso Book",
	}
	books[2] = Book{
		ID:    2,
		Title: "The Second Book",
	}

	espo := espresso.New()
	// Log to stdout for Output
	espo.AddModule(espresso.LogModule.ProvideWithFunc(func(ctx context.Context) (*slog.Logger, error) {
		removeTime := func(groups []string, a slog.Attr) slog.Attr {
			// Remove time from the output for predictable test output.
			if a.Key == slog.TimeKey {
				return slog.Attr{}
			}
			return a
		}

		opt := slog.HandlerOptions{
			ReplaceAttr: removeTime,
		}
		return slog.New(slog.NewTextHandler(os.Stdout, &opt)), nil
	}))

	espo.AddModule(espresso.ProvideCodecs)

	router := espo.WithPrefix("/http")
	router.HandleFunc(func(ctx espresso.Context) error {
		var id int
		if err := ctx.Endpoint(http.MethodGet, "/book/{id}").
			BindPath("id", &id).
			End(); err != nil {
			return err
		}

		book, ok := books[id]
		if !ok {
			return espresso.Error(http.StatusNotFound, fmt.Errorf("not found"))
		}

		if err := espresso.CodecsModule.Value(ctx).EncodeResponse(ctx, &book); err != nil {
			return err
		}

		return nil
	})
	router.HandleFunc(func(ctx espresso.Context) error {
		if err := ctx.Endpoint(http.MethodPost, "/book").
			End(); err != nil {
			return err
		}

		codecs := espresso.CodecsModule.Value(ctx)

		var book Book
		if err := codecs.DecodeRequest(ctx, &book); err != nil {
			return espresso.Error(http.StatusBadRequest, err)
		}

		book.ID = len(books)
		books[book.ID] = book

		if err := codecs.EncodeResponse(ctx, &book); err != nil {
			return err
		}

		return nil
	})

	svr := httptest.NewServer(espo)
	defer svr.Close()

	func() {
		var book Book
		resp, err := http.Get(svr.URL + "/http/book/1")
		if err != nil {
			panic(err)
		}
		defer resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			panic(resp.Status)
		}

		if err := json.NewDecoder(resp.Body).Decode(&book); err != nil {
			panic(err)
		}

		fmt.Println("Book 1 title:", book.Title)
	}()

	func() {
		arg := Book{Title: "The New Book"}

		var buf bytes.Buffer
		if err := json.NewEncoder(&buf).Encode(&arg); err != nil {
			panic(err)
		}

		resp, err := http.Post(svr.URL+"/http/book", "application/json", &buf)
		if err != nil {
			panic(err)
		}
		defer resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			panic(resp.Status)
		}

		var ret Book
		if err := json.NewDecoder(resp.Body).Decode(&ret); err != nil {
			panic(err)
		}

		fmt.Println("The New Book id:", ret.ID)
	}()

	// Output:
	// level=INFO msg="receive http" method=GET path=/http/book/1
	// level=INFO msg="finish http" method=GET path=/http/book/1
	// Book 1 title: The Espresso Book
	// level=INFO msg="receive http" method=POST path=/http/book
	// level=INFO msg="finish http" method=POST path=/http/book
	// The New Book id: 2
}

func ExampleEspresso_rpc() {
	type Book struct {
		ID    int    `json:"id"`
		Title string `json:"title"`
	}
	type Books map[int]Book

	books := make(Books)
	books[1] = Book{
		ID:    1,
		Title: "The Espresso Book",
	}
	books[2] = Book{
		ID:    2,
		Title: "The Second Book",
	}

	espo := espresso.New()
	// Log to stdout for Output
	espo.AddModule(espresso.LogModule.ProvideWithFunc(func(ctx context.Context) (*slog.Logger, error) {
		removeTime := func(groups []string, a slog.Attr) slog.Attr {
			// Remove time from the output for predictable test output.
			if a.Key == slog.TimeKey {
				return slog.Attr{}
			}
			return a
		}

		opt := slog.HandlerOptions{
			ReplaceAttr: removeTime,
		}
		return slog.New(slog.NewTextHandler(os.Stdout, &opt)), nil
	}))
	espo.AddModule(espresso.ProvideCodecs)

	router := espo.WithPrefix("/rpc")
	router.HandleFunc(espresso.RPCRetrive(func(ctx espresso.Context) (*Book, error) {
		var id int
		if err := ctx.Endpoint(http.MethodGet, "/book/{id}").
			BindPath("id", &id).
			End(); err != nil {
			return nil, err
		}

		book, ok := books[id]
		if !ok {
			return nil, espresso.Error(http.StatusNotFound, fmt.Errorf("not found"))
		}

		return &book, nil
	}))
	router.HandleFunc(espresso.RPC(func(ctx espresso.Context, book *Book) (*Book, error) {
		if err := ctx.Endpoint(http.MethodPost, "/book").
			End(); err != nil {
			return nil, err
		}

		book.ID = len(books)
		books[book.ID] = *book

		return book, nil
	}))

	svr := httptest.NewServer(espo)
	defer svr.Close()

	func() {
		var book Book
		resp, err := http.Get(svr.URL + "/rpc/book/1")
		if err != nil {
			panic(err)
		}
		defer resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			panic(resp.Status)
		}

		if err := json.NewDecoder(resp.Body).Decode(&book); err != nil {
			panic(err)
		}

		fmt.Println("Book 1 title:", book.Title)
	}()

	func() {
		arg := Book{Title: "The New Book"}

		var buf bytes.Buffer
		if err := json.NewEncoder(&buf).Encode(&arg); err != nil {
			panic(err)
		}

		resp, err := http.Post(svr.URL+"/rpc/book", "application/json", &buf)
		if err != nil {
			panic(err)
		}
		defer resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			panic(resp.Status)
		}

		var ret Book
		if err := json.NewDecoder(resp.Body).Decode(&ret); err != nil {
			panic(err)
		}

		fmt.Println("The New Book id:", ret.ID)
	}()

	// Output:
	// level=INFO msg="receive http" method=GET path=/rpc/book/1
	// level=INFO msg="finish http" method=GET path=/rpc/book/1
	// Book 1 title: The Espresso Book
	// level=INFO msg="receive http" method=POST path=/rpc/book
	// level=INFO msg="finish http" method=POST path=/rpc/book
	// The New Book id: 2
}