refactor: internal package

internal/httpx/mock.go

@@ -0,0 +1,96 @@
+package httpx
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path"
+	"path/filepath"
+)
+
+var contentTypes = map[string]string{
+	".json": "application/json",
+	".txt":  "text/plain",
+}
+
+// MockClient serves responses from the file system instead of remote calls.
+// Should be used for testing purposes only.
+type MockClient struct {
+	dir string
+}
+
+// Mock creates a new MockClient and installs it instead of the default one.
+func Mock(path ...string) *MockClient {
+	dir := filepath.Join("testdata", filepath.Join(path...))
+	c := &MockClient{dir: dir}
+	client = c
+	return c
+}
+
+// Do serves the file according to the request URL.
+func (c *MockClient) Do(req *http.Request) (*http.Response, error) {
+	filename := filepath.Join(c.dir, path.Base(req.URL.Path))
+
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		resp := http.Response{
+			Status:     http.StatusText(http.StatusNotFound),
+			StatusCode: http.StatusNotFound,
+		}
+		return &resp, nil
+	}
+
+	cType, ok := contentTypes[path.Ext(filename)]
+	if !ok {
+		cType = "application/octet-stream"
+	}
+	rdr := respond(cType, data)
+	resp, err := http.ReadResponse(bufio.NewReader(rdr), req)
+	if err != nil {
+		panic(err)
+	}
+	return resp, nil
+}
+
+func respond(cType string, data []byte) io.Reader {
+	buf := bytes.Buffer{}
+	buf.WriteString("HTTP/1.1 200 OK\n")
+	buf.WriteString(fmt.Sprintf("Content-Type: %s\n\n", cType))
+	_, err := buf.Write(data)
+	if err != nil {
+		panic(err)
+	}
+	return &buf
+}
+
+// MockServer creates a mock HTTP server and installs its client
+// instead of the default one. Serves responses from the file system
+// instead of remote calls. Should be used for testing purposes only.
+func MockServer() *httptest.Server {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		filename := filepath.Join("testdata", path.Base(r.URL.Path))
+
+		data, err := os.ReadFile(filename)
+		if err != nil {
+			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+			return
+		}
+
+		cType, ok := contentTypes[path.Ext(filename)]
+		if !ok {
+			cType = "application/octet-stream"
+		}
+
+		w.Header().Set("content-type", cType)
+		_, err = w.Write(data)
+		if err != nil {
+			panic(err)
+		}
+	}))
+	client = srv.Client()
+	return srv
+}