feat: add httpc.Do & httpc.Service.Do (#1775)

* backup

* backup

* backup

* feat: add httpc.Do & httpc.Service.Do

* fix: not using strings.Cut, it's from Go 1.18

* chore: remove redudant code

* feat: httpc.Do finished

* chore: fix reviewdog

* chore: break loop if found

* add more tests

rest/httpc/requests.go

@@ -1,8 +1,17 @@
 package httpc
 
 import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
 	"net/http"
+	nurl "net/url"
+	"strings"
 
+	"github.com/zeromicro/go-zero/core/lang"
+	"github.com/zeromicro/go-zero/core/mapping"
 	"github.com/zeromicro/go-zero/rest/httpc/internal"
 )
 
@@ -10,6 +19,17 @@ var interceptors = []internal.Interceptor{
 	internal.LogInterceptor,
 }
 
+// Do sends an HTTP request with the given arguments and returns an HTTP response.
+// data is automatically marshal into a *httpRequest, typically it's defined in an API file.
+func Do(ctx context.Context, method, url string, data interface{}) (*http.Response, error) {
+	req, err := buildRequest(ctx, method, url, data)
+	if err != nil {
+		return nil, err
+	}
+
+	return DoRequest(req)
+}
+
 // DoRequest sends an HTTP request and returns an HTTP response.
 func DoRequest(r *http.Request) (*http.Response, error) {
 	return request(r, defaultClient{})
@@ -27,6 +47,107 @@ func (c defaultClient) do(r *http.Request) (*http.Response, error) {
 	return http.DefaultClient.Do(r)
 }
 
+func buildFormQuery(u *nurl.URL, val map[string]interface{}) string {
+	query := u.Query()
+	for k, v := range val {
+		query.Add(k, fmt.Sprint(v))
+	}
+
+	return query.Encode()
+}
+
+func buildRequest(ctx context.Context, method, url string, data interface{}) (*http.Request, error) {
+	u, err := nurl.Parse(url)
+	if err != nil {
+		return nil, err
+	}
+
+	var val map[string]map[string]interface{}
+	if data != nil {
+		val, err = mapping.Marshal(data)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err := fillPath(u, val[pathKey]); err != nil {
+		return nil, err
+	}
+
+	var reader io.Reader
+	jsonVars, hasJsonBody := val[jsonKey]
+	if hasJsonBody {
+		if method == http.MethodGet {
+			return nil, ErrGetWithBody
+		}
+
+		var buf bytes.Buffer
+		enc := json.NewEncoder(&buf)
+		if err := enc.Encode(jsonVars); err != nil {
+			return nil, err
+		}
+
+		reader = &buf
+	}
+
+	req, err := http.NewRequestWithContext(ctx, method, u.String(), reader)
+	if err != nil {
+		return nil, err
+	}
+
+	req.URL.RawQuery = buildFormQuery(u, val[formKey])
+	fillHeader(req, val[headerKey])
+	if hasJsonBody {
+		req.Header.Set(contentType, applicationJson)
+	}
+
+	return req, nil
+}
+
+func fillHeader(r *http.Request, val map[string]interface{}) {
+	for k, v := range val {
+		r.Header.Add(k, fmt.Sprint(v))
+	}
+}
+
+func fillPath(u *nurl.URL, val map[string]interface{}) error {
+	used := make(map[string]lang.PlaceholderType)
+	fields := strings.Split(u.Path, slash)
+
+	for i := range fields {
+		field := fields[i]
+		if len(field) > 0 && field[0] == colon {
+			name := field[1:]
+			ival, ok := val[name]
+			if !ok {
+				return fmt.Errorf("missing path variable %q", name)
+			}
+			value := fmt.Sprint(ival)
+			if len(value) == 0 {
+				return fmt.Errorf("empty path variable %q", name)
+			}
+			fields[i] = value
+			used[name] = lang.Placeholder
+		}
+	}
+
+	if len(val) != len(used) {
+		for key := range used {
+			delete(val, key)
+		}
+
+		var unused []string
+		for key := range val {
+			unused = append(unused, key)
+		}
+
+		return fmt.Errorf("more path variables are provided: %q", strings.Join(unused, ", "))
+	}
+
+	u.Path = strings.Join(fields, slash)
+	return nil
+}
+
 func request(r *http.Request, cli client) (*http.Response, error) {
 	var respHandlers []internal.ResponseHandler
 	for _, interceptor := range interceptors {