ex

README

ex - implements interfaces which write output to stdout

This is useful for writing short Examples in go, eg. when testing output from http handlers.

Examples

Writers implement the http.ResponseWriter interface

JsonWriter

r := bytes.NewBufferString(`{"name":"John","car":{"model":"x,2","plate":"abc123"}}`)
io.Copy(jsonWriter, r)

Output:

{
    "name":"John",
    "car":{
        "model":"x,2",
        "plate":"abc123"
    }
}

StatusWriter

w := NewStatusWriter()
w.Write([]byte("Hello, world!"))

Output:

200

BodyWriter

bodyWriter.Write([]byte("Hello, world!"))

Output:

Hello, world!

Documentation

Overview

Package ex implements interfaces which writes output to stdout

Index

• func DumpParts(msg io.Reader, boundary string)
• func Print(any ...interface{})
• func Tfprint(tidy TidyFunc, w io.Writer, any ...interface{})
• func Tprint(tidy TidyFunc, any ...interface{})
• type BodyWriter
  • func BodyOf(r *http.Request, err error) (*BodyWriter, *http.Request)
  • func NewBodyWriter() *BodyWriter
  • func (w *BodyWriter) Header() http.Header
  • func (w *BodyWriter) Write(b []byte) (int, error)
  • func (w *BodyWriter) WriteHeader(v int)
• type HeaderWriter
  • func HeadersOf(r *http.Request, err error) (*HeaderWriter, *http.Request)
  • func NewHeaderWriter() *HeaderWriter
  • func (w *HeaderWriter) Header() http.Header
  • func (w *HeaderWriter) Write(b []byte) (int, error)
  • func (w *HeaderWriter) WriteHeader(v int)
• type JsonWriter
  • func JsonOf(r *http.Request, err error) (*JsonWriter, *http.Request)
  • func NewJsonWriter() *JsonWriter
  • func (w *JsonWriter) Header() http.Header
  • func (w *JsonWriter) Write(b []byte) (int, error)
  • func (w *JsonWriter) WriteHeader(v int)
  • func (w *JsonWriter) WriteTo(out io.Writer, b []byte) (int, error)
• type StatusWriter
  • func NewStatusWriter() *StatusWriter
  • func StatusOf(r *http.Request, err error) (*StatusWriter, *http.Request)
  • func (w *StatusWriter) Header() http.Header
  • func (w *StatusWriter) Write(b []byte) (int, error)
  • func (w *StatusWriter) WriteHeader(v int)
• type TidyFunc

Examples

• BodyOf
• BodyWriter.Write
• BodyWriter.WriteHeader
• DumpParts
• DumpParts (With_nice_json)
• HeaderWriter.Write
• HeaderWriter.WriteHeader
• HeadersOf
• JsonOf
• JsonWriter.Write
• JsonWriter.Write (Specific_output)
• JsonWriter.WriteHeader
• JsonWriter.WriteTo
• Print
• StatusOf
• StatusWriter.Write
• StatusWriter.WriteHeader
• Tprint

Functions

func DumpParts

func DumpParts(msg io.Reader, boundary string)

DumpParts prints each part of a multipart message

Example

buf := bytes.NewBufferString("")
body := multipart.NewWriter(buf)
body.SetBoundary("--X")

w, _ := body.CreatePart(textproto.MIMEHeader{})
w.Write([]byte("Hello"))

w, _ = body.CreatePart(textproto.MIMEHeader{})
w.Write([]byte(", world!"))

DumpParts(buf, "--X")

Output:

Hello, world!

Example (With_nice_json)

buf := bytes.NewBufferString("")
body := multipart.NewWriter(buf)
body.SetBoundary("--X")

header := textproto.MIMEHeader{}
header["Content-Type"] = []string{"application/json"}
w, _ := body.CreatePart(header)
w.Write([]byte(`{"text":"hello","more":"world"}`))

w, _ = body.CreatePart(textproto.MIMEHeader{})
w.Write([]byte("next part"))

DumpParts(buf, "--X")

Output:

{
    "text":"hello",
    "more":"world"
}
next part

func Print

func Print(any ...interface{})

Print writes any element to stdout.

Example

h := http.Header{}
h.Add("Content-Type", "text/plain")
h.Add("Abbe", "one")
h.Add("Abbe", "two")
Print(h)

Output:

Abbe: one
Abbe: two
Content-Type: text/plain

func Tfprint

func Tfprint(tidy TidyFunc, w io.Writer, any ...interface{})

func Tprint

func Tprint(tidy TidyFunc, any ...interface{})

Example

h := http.Header{}
h.Add("Content-Type", "text/plain")
h.Add("Abbe", "one")
h.Add("Abbe", "two")
tidy := func(v string) string {
	return strings.Replace(v, "one", "zero", -1)
}
Tprint(tidy, h)

Output:

Abbe: zero
Abbe: two
Content-Type: text/plain

Types

type BodyWriter

type BodyWriter struct {
	// contains filtered or unexported fields
}

func BodyOf

func BodyOf(r *http.Request, err error) (*BodyWriter, *http.Request)

Example

handler := func(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello, %s!", "world")
}
handler(BodyOf(http.NewRequest("GET", "/", nil)))

Output:

Hello, world!

func NewBodyWriter

func NewBodyWriter() *BodyWriter

func (*BodyWriter) Header

func (w *BodyWriter) Header() http.Header

func (*BodyWriter) Write

func (w *BodyWriter) Write(b []byte) (int, error)

Write the given byte slice to stdout

Example

bodyWriter.Write([]byte("Hello, world!"))

Output:

Hello, world!

func (*BodyWriter) WriteHeader

func (w *BodyWriter) WriteHeader(v int)

Example

bodyWriter.WriteHeader(200)

type HeaderWriter

type HeaderWriter struct {
	// contains filtered or unexported fields
}

func HeadersOf

func HeadersOf(r *http.Request, err error) (*HeaderWriter, *http.Request)

Example

handler := func(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	fmt.Fprintf(w, "Hello, %s!", "world")
}
handler(HeadersOf(http.NewRequest("GET", "/", nil)))

func NewHeaderWriter

func NewHeaderWriter() *HeaderWriter

func (*HeaderWriter) Header

func (w *HeaderWriter) Header() http.Header

func (*HeaderWriter) Write

func (w *HeaderWriter) Write(b []byte) (int, error)

Write the given byte slice to stdout

Example

headerWriter.Write([]byte("body not visible"))

func (*HeaderWriter) WriteHeader

func (w *HeaderWriter) WriteHeader(v int)

Example

w := NewHeaderWriter()
w.Header().Add("Content-type", "text/plain")
w.Header().Add("Accept", "*")
w.Header().Add("Accept", "application/json")
w.Write([]byte("body not visible"))
w.Write([]byte("second write does nothing"))

Output:

Accept: *; application/json
Content-Type: text/plain

type JsonWriter

type JsonWriter struct {
	Out io.Writer
	// contains filtered or unexported fields
}

JsonWriter formats incomming json and implements http.ResponseWriter.

func JsonOf

func JsonOf(r *http.Request, err error) (*JsonWriter, *http.Request)

Example

handler := func(w http.ResponseWriter, r *http.Request) {
	json.NewEncoder(w).Encode(
		struct {
			Message string
		}{"Hello, World!"})
}
handler(JsonOf(http.NewRequest("GET", "/", nil)))

Output:

{
    "Message":"Hello, World!"
}

func NewJsonWriter

func NewJsonWriter() *JsonWriter

func (*JsonWriter) Header

func (w *JsonWriter) Header() http.Header

func (*JsonWriter) Write

func (w *JsonWriter) Write(b []byte) (int, error)

Write the given byte slice to stdout

Example

json := `{"name":"John","car":{"model":"x,2","plate":"abc\"123"}}`
reader := bytes.NewBufferString(json)
io.Copy(jsonWriter, reader)

Output:

{
    "name":"John",
    "car":{
        "model":"x,2",
        "plate":"abc\"123"
    }
}

Example (Specific_output)

json := `{"name":"John","car":{"model":"x,2","plate":"abc\"123"}}`
reader := bytes.NewBufferString(json)
jsonWriter := NewJsonWriter()
jsonWriter.Out = os.Stdout
io.Copy(jsonWriter, reader)

Output:

{
    "name":"John",
    "car":{
        "model":"x,2",
        "plate":"abc\"123"
    }
}

func (*JsonWriter) WriteHeader

func (w *JsonWriter) WriteHeader(v int)

Example

jsonWriter.WriteHeader(200)

func (*JsonWriter) WriteTo

func (w *JsonWriter) WriteTo(out io.Writer, b []byte) (int, error)

Write the given byte slice to stdout

Example

json := `{"name":"John","car":{"model":"x,2","plate":"abc\"123"}}`
buf := bytes.NewBufferString("")
jsonWriter.WriteTo(buf, []byte(json))
fmt.Print(buf.String())

Output:

{
    "name":"John",
    "car":{
        "model":"x,2",
        "plate":"abc\"123"
    }
}

type StatusWriter

type StatusWriter struct {
	// contains filtered or unexported fields
}

func NewStatusWriter

func NewStatusWriter() *StatusWriter

func StatusOf

func StatusOf(r *http.Request, err error) (*StatusWriter, *http.Request)

Example

handler := func(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
}
handler(StatusOf(http.NewRequest("GET", "/", nil)))

Output:

200

func (*StatusWriter) Header

func (w *StatusWriter) Header() http.Header

func (*StatusWriter) Write

func (w *StatusWriter) Write(b []byte) (int, error)

Example

w := NewStatusWriter()
w.Write([]byte("Hello, world!"))

Output:

200

func (*StatusWriter) WriteHeader

func (w *StatusWriter) WriteHeader(v int)

Write the given value to stdout

Example

statusWriter.WriteHeader(200)

Output:

200

type TidyFunc

type TidyFunc func(string) string