feat(fastestvpn): update servers data using API instead of zip file

- Add city filter
- More dynamic to servers updates on fastestvpn's end
- Update servers data

internal/provider/fastestvpn/updater/api_test.go

@@ -0,0 +1,164 @@
+package updater
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/qdm12/gluetun/internal/provider/common"
+	"github.com/stretchr/testify/assert"
+)
+
+type roundTripFunc func(r *http.Request) (*http.Response, error)
+
+func (f roundTripFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+	return f(r)
+}
+
+func Test_fechAPIServers(t *testing.T) {
+	t.Parallel()
+
+	errTest := errors.New("test error")
+
+	testCases := map[string]struct {
+		ctx            context.Context
+		protocol       string
+		requestBody    string
+		responseStatus int
+		responseBody   io.ReadCloser
+		transportErr   error
+		servers        []apiServer
+		errWrapped     error
+		errMessage     string
+	}{
+		"transport_error": {
+			ctx:            context.Background(),
+			protocol:       "tcp",
+			requestBody:    "action=vpn_servers&protocol=tcp",
+			responseStatus: http.StatusOK,
+			transportErr:   errTest,
+			errWrapped:     errTest,
+			errMessage: `sending request: Post ` +
+				`"https://support.fastestvpn.com/wp-admin/admin-ajax.php": ` +
+				`test error`,
+		},
+		"not_found_status_code": {
+			ctx:            context.Background(),
+			protocol:       "tcp",
+			requestBody:    "action=vpn_servers&protocol=tcp",
+			responseStatus: http.StatusNotFound,
+			errWrapped:     common.ErrHTTPStatusCodeNotOK,
+			errMessage:     "HTTP status code not OK: 404",
+		},
+		"empty_data": {
+			ctx:            context.Background(),
+			protocol:       "tcp",
+			requestBody:    "action=vpn_servers&protocol=tcp",
+			responseStatus: http.StatusOK,
+			responseBody:   io.NopCloser(strings.NewReader("")),
+			servers:        []apiServer{},
+		},
+		"single_server": {
+			ctx:            context.Background(),
+			protocol:       "tcp",
+			requestBody:    "action=vpn_servers&protocol=tcp",
+			responseStatus: http.StatusOK,
+			responseBody: io.NopCloser(strings.NewReader(
+				"irrelevant<tr><td>Australia</td><td>Sydney</td>" +
+					"<td>au-stream.jumptoserver.com</td></tr>irrelevant")),
+			servers: []apiServer{
+				{country: "Australia", city: "Sydney", hostname: "au-stream.jumptoserver.com"},
+			},
+		},
+		"two_servers": {
+			ctx:            context.Background(),
+			protocol:       "tcp",
+			requestBody:    "action=vpn_servers&protocol=tcp",
+			responseStatus: http.StatusOK,
+			responseBody: io.NopCloser(strings.NewReader(
+				"<tr><td>Australia</td><td>Sydney</td><td>au-stream.jumptoserver.com</td></tr>" +
+					"<tr><td>Australia</td><td>Sydney</td><td>au-01.jumptoserver.com</td></tr>")),
+			servers: []apiServer{
+				{country: "Australia", city: "Sydney", hostname: "au-stream.jumptoserver.com"},
+				{country: "Australia", city: "Sydney", hostname: "au-01.jumptoserver.com"},
+			},
+		},
+	}
+
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			client := &http.Client{
+				Transport: roundTripFunc(func(r *http.Request) (*http.Response, error) {
+					assert.Equal(t, apiURL, r.URL.String())
+					requestBody, err := io.ReadAll(r.Body)
+					assert.NoError(t, err)
+					assert.Equal(t, testCase.requestBody, string(requestBody))
+					if testCase.transportErr != nil {
+						return nil, testCase.transportErr
+					}
+					return &http.Response{
+						StatusCode: testCase.responseStatus,
+						Body:       testCase.responseBody,
+					}, nil
+				}),
+			}
+
+			entries, err := fetchAPIServers(testCase.ctx, client, testCase.protocol)
+
+			assert.ErrorIs(t, err, testCase.errWrapped)
+			if testCase.errWrapped != nil {
+				assert.EqualError(t, err, testCase.errMessage)
+			}
+			assert.Equal(t, testCase.servers, entries)
+		})
+	}
+}
+
+func Test_getNextBlock(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		data       string
+		startToken string
+		endToken   string
+		nextBlock  []byte
+	}{
+		"empty_data": {
+			startToken: "<a>",
+			endToken:   "</a>",
+		},
+		"start_token_not_found": {
+			data:       "test</a>",
+			startToken: "<a>",
+			endToken:   "</a>",
+		},
+		"end_token_not_found": {
+			data:       "<a>test",
+			startToken: "<a>",
+			endToken:   "</a>",
+		},
+		"block_found": {
+			data:       "xy<a>test</a><a>test2</a>zx",
+			startToken: "<a>",
+			endToken:   "</a>",
+			nextBlock:  []byte("<a>test</a>"),
+		},
+	}
+
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			nextBlock := getNextBlock([]byte(testCase.data), testCase.startToken, testCase.endToken)
+
+			assert.Equal(t, testCase.nextBlock, nextBlock)
+		})
+	}
+}