withttp

Build http requests and parse their responses with fluent syntax and wit. This package aims to quickly configure http roundtrips by covering common scenarios, while leaving all details of http requests and responses open for developers to allow maximum flexibility.

Supported underlying http implementations are:

• net/http
• fasthttp
• Wrap your client with Client interface ...
• ... or open an issue to include your preferred one!

Query Restful endpoints

type GithubRepoInfo struct {
  ID  int    `json:"id"`
  URL string `json:"html_url"`
}

func GetRepoInfo(user, repo string) (GithubRepoInfo, error) {

  call := withttp.NewCall[GithubRepoInfo](withttp.WithFasthttp()).
    WithURL(fmt.Sprintf("https://api.github.com/repos/%s/%s", user, repo)).
    WithMethod(http.MethodGet).
    WithHeader("User-Agent", "withttp/0.5.1 See https://github.com/sonirico/withttp", false).
    WithParseJSON().
    WithExpectedStatusCodes(http.StatusOK)

  err := call.Call(context.Background())

  return call.BodyParsed, err
}

func main() {
  info, _ := GetRepoInfo("sonirico", "withttp")
  log.Println(info)
}

Stream data to server (from a slice)

See full example

type metric struct {
  Time time.Time `json:"t"`
  Temp float32   `json:"T"`
}

func CreateStream() error {
  points := []metric{
    {
      Time: time.Unix(time.Now().Unix()-1, 0),
      Temp: 39,
    },
    {
      Time: time.Now(),
      Temp: 40,
    },
  }

  stream := withttp.Slice[metric](points)

  testEndpoint := withttp.NewEndpoint("webhook-site-request-stream-example").
    Request(
      withttp.WithBaseURL("https://webhook.site/24e84e8f-75cf-4239-828e-8bed244c0afb"),
    )

  call := withttp.NewCall[any](withttp.WithFasthttp()).
    WithMethod(http.MethodPost).
    WithContentType(withttp.ContentTypeJSONEachRow).
    WithRequestSniffed(func(data []byte, err error) {
      fmt.Printf("recv: '%s', err: %v", string(data), err)
    }).
    WithRequestStreamBody(
      withttp.WithRequestStreamBody[any, metric](stream),
    ).
    WithExpectedStatusCodes(http.StatusOK)

  return call.CallEndpoint(context.Background(), testEndpoint)
}

Stream data to server (from a channel)

See full example

func CreateStreamChannel() error {
  points := make(chan metric, 2)

  go func() {
    points <- metric{
      Time: time.Unix(time.Now().Unix()-1, 0),
      Temp: 39,
    }

    points <- metric{
      Time: time.Now(),
      Temp: 40,
    }

    close(points)
  }()

  stream := withttp.Channel[metric](points)

  testEndpoint := withttp.NewEndpoint("webhook-site-request-stream-example").
    Request(
      withttp.WithBaseURL("https://webhook.site/24e84e8f-75cf-4239-828e-8bed244c0afb"),
    )

  call := withttp.NewCall[any](withttp.WithFasthttp()).
    WithMethod(http.MethodPost).
    WithContentType(withttp.ContentTypeJSONEachRow).
    WithRequestSniffed(func(data []byte, err error) {
      fmt.Printf("recv: '%s', err: %v", string(data), err)
    }).
    WithRequestStreamBody(
      withttp.WithRequestStreamBody[any, metric](stream),
    ).
    WithExpectedStatusCodes(http.StatusOK)

  return call.CallEndpoint(context.Background(), testEndpoint)
}

Stream data to server (from a reader)

See full example

func CreateStreamReader() error {
  buf := bytes.NewBuffer(nil)

  go func() {
    buf.WriteString("{\"t\":\"2022-09-01T00:58:15+02:00\"")
    buf.WriteString(",\"T\":39}\n{\"t\":\"2022-09-01T00:59:15+02:00\",\"T\":40}\n")
  }()

  streamFactory := withttp.NewProxyStreamFactory(1 << 10)

  stream := withttp.NewStreamFromReader(buf, streamFactory)

  testEndpoint := withttp.NewEndpoint("webhook-site-request-stream-example").
    Request(
      withttp.WithBaseURL("https://webhook.site/24e84e8f-75cf-4239-828e-8bed244c0afb"),
    )

  call := withttp.NewCall[any](withttp.WithNetHttp()).
    WithMethod(http.MethodPost).
    WithRequestSniffed(func(data []byte, err error) {
      fmt.Printf("recv: '%s', err: %v", string(data), err)
    }).
    WithContentType(withttp.ContentTypeJSONEachRow).
    WithRequestStreamBody(
      withttp.WithRequestStreamBody[any, []byte](stream),
    ).
    WithExpectedStatusCodes(http.StatusOK)

  return call.CallEndpoint(context.Background(), testEndpoint)
}

Several endpoints

In case of a wide range catalog of endpoints, predefined parameters and behaviours can be defined by employing an endpoint definition.

var (
  githubApi = withttp.NewEndpoint("GithubAPI").
    Request(withttp.WithBaseURL("https://api.github.com/"))
)

type GithubRepoInfo struct {
  ID  int    `json:"id"`
  URL string `json:"html_url"`
}

func GetRepoInfo(user, repo string) (GithubRepoInfo, error) {
  call := withttp.NewCall[GithubRepoInfo](withttp.WithFasthttp()).
    WithURI(fmt.Sprintf("repos/%s/%s", user, repo)).
    WithMethod(http.MethodGet).
    WithHeader("User-Agent", "withttp/0.5.1 See https://github.com/sonirico/withttp", false).
    WithHeaderFunc(func() (key, value string, override bool) {
      key = "X-Date"
      value = time.Now().String()
      override = true
      return
    }).
    WithParseJSON().
    WithExpectedStatusCodes(http.StatusOK)

  err := call.CallEndpoint(context.Background(), githubApi)

  return call.BodyParsed, err
}

type GithubCreateIssueResponse struct {
  ID  int    `json:"id"`
  URL string `json:"url"`
}

func CreateRepoIssue(user, repo, title, body, assignee string) (GithubCreateIssueResponse, error) {
  type payload struct {
    Title    string `json:"title"`
    Body     string `json:"body"`
    Assignee string `json:"assignee"`
  }

  p := payload{
    Title:    title,
    Body:     body,
    Assignee: assignee,
  }

  call := withttp.NewCall[GithubCreateIssueResponse](
    withttp.WithFasthttp(),
  ).
    WithURI(fmt.Sprintf("repos/%s/%s/issues", user, repo)).
    WithMethod(http.MethodPost).
    WithContentType("application/vnd+github+json").
    WithBody(p).
    WithHeaderFunc(func() (key, value string, override bool) {
      key = "Authorization"
      value = fmt.Sprintf("Bearer %s", "S3cret")
      override = true
      return
    }).
    WithExpectedStatusCodes(http.StatusCreated)

  err := call.CallEndpoint(context.Background(), githubApi)

  log.Println("req body", string(call.Req.Body()))

  return call.BodyParsed, err
}

func main() {
  // Fetch repo info
  info, _ := GetRepoInfo("sonirico", "withttp")
  log.Println(info)

  // Create an issue
  res, err := CreateRepoIssue("sonirico", "withttp", "test",
    "This is a test", "sonirico")
  log.Println(res, err)
}

Test your calls again a mock endpoint

Quickly test your calls by creating a mock endpoint

var (
  exchangeListOrders = withttp.NewEndpoint("ListOrders").
        Request(withttp.WithBaseURL("http://example.com")).
        Response(
      withttp.WithMockedRes(func(res withttp.Response) {
        res.SetBody(io.NopCloser(bytes.NewReader(mockResponse)))
        res.SetStatus(http.StatusOK)
      }),
    )
  mockResponse = []byte(strings.TrimSpace(`
    {"amount": 234, "pair": "BTC/USDT"}
    {"amount": 123, "pair": "ETH/USDT"}`))
)

func main() {
  type Order struct {
    Amount float64 `json:"amount"`
    Pair   string  `json:"pair"`
  }

  res := make(chan Order)

  call := withttp.NewCall[Order](withttp.WithFasthttp()).
    WithURL("https://github.com/").
    WithMethod(http.MethodGet).
    WithHeader("User-Agent", "withttp/0.5.1 See https://github.com/sonirico/withttp", false).
    WithParseJSONEachRowChan(res).
    WithExpectedStatusCodes(http.StatusOK)

  go func() {
    for order := range res {
      log.Println(order)
    }
  }()

  err := call.CallEndpoint(context.Background(), exchangeListOrders)

  if err != nil {
    panic(err)
  }
}

TODO:

• Form-data content type codecs
• More quality-of-life methods for auth
• Able to parse more content types:
  • tabular separated
  • xml
  • gRPC