Initial commit

.gitignore

@@ -0,0 +1 @@
+.idea

cmd/gen.go

@@ -0,0 +1,157 @@
+// Generates a README.md from the README.tpl and provides some template helpers.
+package main
+
+import (
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"io/ioutil"
+	"os"
+	"strings"
+	"text/template"
+	"unicode"
+	"unicode/utf8"
+)
+
+func main() {
+	if err := run(); err != nil {
+		println(err.Error())
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	const tplName = "README.tpl"
+	tplVal, err := ioutil.ReadFile(tplName)
+	if err != nil {
+		return fmt.Errorf("can't read a file %q: %w", tplName, err)
+	}
+
+	tpl := template.New("readme").Funcs(template.FuncMap{
+		"quote_go_func": func(fileName, funcName string) (string, error) {
+			fileVal, err := ioutil.ReadFile(fileName)
+			if err != nil {
+				return "", fmt.Errorf("can't read a file %q: %w", fileName, err)
+			}
+
+			fileValS := string(fileVal)
+			f, err := parser.ParseFile(token.NewFileSet(), fileName, fileValS, 0)
+			if err != nil {
+				return "", fmt.Errorf("can't parse a file %q: %w", fileName, err)
+			}
+			found := false
+			var functionBody string
+			ast.Inspect(f, func(node ast.Node) bool {
+				if found {
+					return false
+				}
+				fDecl, ok := node.(*ast.FuncDecl)
+				if ok && fDecl.Name.Name == funcName && fDecl.Body != nil {
+					found = true
+					functionBody = fileValS[fDecl.Pos()-1 : fDecl.End()]
+					return false
+				}
+
+				return true
+			})
+
+			if !found {
+				return "", fmt.Errorf("can't read a file %q: %w", fileName, err)
+			}
+
+			return resetIndents(functionBody), nil
+		},
+		"quote_go_func_body": func(fileName, funcName string) (string, error) {
+			fileVal, err := ioutil.ReadFile(fileName)
+			if err != nil {
+				return "", fmt.Errorf("can't read a file %q: %w", fileName, err)
+			}
+
+			fileValS := string(fileVal)
+			f, err := parser.ParseFile(token.NewFileSet(), fileName, fileValS, 0)
+			if err != nil {
+				return "", fmt.Errorf("can't parse a file %q: %w", fileName, err)
+			}
+			found := false
+			var functionBody string
+			ast.Inspect(f, func(node ast.Node) bool {
+				if found {
+					return false
+				}
+				fDecl, ok := node.(*ast.FuncDecl)
+				if ok && fDecl.Name.Name == funcName && fDecl.Body != nil {
+					found = true
+					functionBody = fileValS[fDecl.Body.Pos() : fDecl.Body.End()-2]
+					return false
+				}
+
+				return true
+			})
+
+			if !found {
+				return "", fmt.Errorf("can't read a file %q: %w", fileName, err)
+			}
+			return resetIndents(functionBody), nil
+		},
+		"quote_file": func(fileName string) (string, error) {
+			fileVal, err := ioutil.ReadFile(fileName)
+			if err != nil {
+				return "", fmt.Errorf("can't read a file %q: %w", fileName, err)
+			}
+
+			return strings.TrimRight(string(fileVal), "\n"), nil
+		},
+		"indent": indent,
+	})
+
+	if tpl, err = tpl.Parse(string(tplVal)); err != nil {
+		return fmt.Errorf("can't parse a template: %w", err)
+	}
+
+	const resFileName = "README.md"
+	resFile, err := os.Create(resFileName)
+	if err != nil {
+		return fmt.Errorf("can't create a result file %q: %w", resFileName, err)
+	}
+
+	if err = tpl.Execute(resFile, nil); err != nil {
+		return fmt.Errorf("can't execute template: %w", err)
+	}
+
+	return nil
+}
+
+func resetIndents(s string) string {
+	minCountOfLeadingSpaces := -1
+	lines := strings.Split(strings.Trim(s, "\n"), "\n")
+	for _, line := range lines {
+		trimmed := strings.TrimLeftFunc(line, unicode.IsSpace)
+		if utf8.RuneCountInString(trimmed) == 0 {
+			continue
+		}
+		countOfLeadingSpaces := utf8.RuneCountInString(line) - utf8.RuneCountInString(trimmed)
+		if countOfLeadingSpaces < minCountOfLeadingSpaces || minCountOfLeadingSpaces == -1 {
+			minCountOfLeadingSpaces = countOfLeadingSpaces
+		}
+	}
+	if minCountOfLeadingSpaces == 0 {
+		return s
+	}
+	res := ""
+	for i, line := range lines {
+		if i != 0 {
+			res += "\n"
+		}
+		if utf8.RuneCountInString(line) == 0 {
+			continue
+		}
+		res += string([]rune(line)[minCountOfLeadingSpaces:])
+	}
+	return res
+}
+
+func indent(spaces int, v string) string {
+	pad := strings.Repeat(" ", spaces)
+	return pad + strings.Replace(v, "\n", "\n"+pad, -1)
+}

go.mod

@@ -0,0 +1,11 @@
+module github.com/vivid-money/article-golang-di
+
+go 1.13
+
+require (
+	github.com/google/wire v0.4.0
+	go.uber.org/dig v1.10.0
+	go.uber.org/fx v1.13.1
+	go.uber.org/multierr v1.6.0
+	golang.org/x/sync v0.0.0-20190423024810-112230192c58
+)

go.sum

@@ -0,0 +1,65 @@
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+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/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/google/subcommands v1.0.1 h1:/eqq+otEXm5vhfBrbREPCSVQbvofip6kIz+mX5TUH7k=
+github.com/google/subcommands v1.0.1/go.mod h1:ZjhPrFU+Olkh9WazFPsl27BQ4UPiG37m3yTrtFlrHVk=
+github.com/google/wire v0.4.0 h1:kXcsA/rIGzJImVqPdhfnr6q0xsS9gU0515q1EPpJ9fE=
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+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
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pkg/components/dbconn.go

@@ -0,0 +1,41 @@
+package components
+
+import (
+	"context"
+	"sync"
+)
+
+// Fake db connection.
+type DBConn struct {
+	logger Logger
+	once   sync.Once
+}
+
+func NewDBConn(logger Logger) *DBConn {
+	logger.Print("New DBConn")
+	return &DBConn{
+		logger: logger,
+	}
+}
+
+func (h *DBConn) Connect(ctx context.Context) error {
+	h.logger.Print("Connecting DBConn")
+	defer h.logger.Print("Connected DBConn")
+	go func() { // эмулируем остановку соединения по отмене контекста
+		<-ctx.Done()
+		_ = h.Stop(context.Background())
+	}()
+	return nil
+}
+
+func (h *DBConn) Stop(_ context.Context) error {
+	h.once.Do(func() {
+		h.logger.Print("Stop DBConn")
+		defer h.logger.Print("Stopped DBConn")
+	})
+	return nil
+}
+
+func (h *DBConn) Query(_ string) (string, error) {
+	return "Fake result", nil
+}

pkg/components/helper.go

@@ -0,0 +1,18 @@
+package components
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+// Простенький хелпер, чтобы не писать один и тот же код несколько раз.
+func AwaitSignal(ctx context.Context) {
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
+	select {
+	case <-ctx.Done():
+	case <-sig:
+	}
+}

pkg/components/http_server.go

@@ -0,0 +1,61 @@
+package components
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+)
+
+type HTTPServer struct {
+	httpSrv *http.Server
+	conn    *DBConn
+	logger  Logger
+}
+
+func NewHTTPServer(logger Logger, conn *DBConn) *HTTPServer {
+	logger.Print("New HTTPServer")
+	mux := http.NewServeMux()
+
+	s := &HTTPServer{
+		conn:   conn,
+		logger: logger,
+	}
+	mux.HandleFunc("/get", func(writer http.ResponseWriter, _ *http.Request) {
+		res, err := conn.Query("SELECT * FROM something")
+		if err != nil {
+			writer.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		_, _ = writer.Write([]byte(res))
+	})
+	s.httpSrv = &http.Server{
+		Addr:    ":3000",
+		Handler: mux,
+	}
+
+	return s
+}
+
+func (s *HTTPServer) Serve(ctx context.Context) error {
+	s.logger.Print("Serving HTTPServer")
+	defer s.logger.Print("Finished serving HTTPServer")
+	go func() { // вызываем остановку по отмене контекста, так как net/http не умеет работать с контекстами
+		<-ctx.Done()
+		_ = s.Stop(context.Background())
+	}()
+	if err := s.httpSrv.ListenAndServe(); err != nil {
+		return fmt.Errorf("http listen: %w", err)
+	}
+
+	return nil
+}
+
+func (s *HTTPServer) Stop(ctx context.Context) error {
+	s.logger.Print("Stop HTTPServer")
+	defer s.logger.Print("Stopped HTTPServer")
+	if err := s.httpSrv.Shutdown(ctx); err != nil {
+		return fmt.Errorf("http shutdown: %w", err)
+	}
+
+	return nil
+}

pkg/components/logger.go

@@ -0,0 +1,10 @@
+package components
+
+type Logger interface {
+	Print(v ...interface{})
+	Printf(format string, v ...interface{})
+	Fatal(v ...interface{})
+	Fatalf(format string, v ...interface{})
+	Panic(v ...interface{})
+	Panicf(format string, v ...interface{})
+}