Add Unit Tests for config.go

src/config/config_test.go

@@ -0,0 +1,295 @@
+package config
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func tmpDir(t *testing.T) string {
+	t.Helper()
+	dir, err := os.MkdirTemp("", "config_test_*")
+	require.NoError(t, err)
+
+	t.Cleanup(func() {
+		require.NoError(t, os.RemoveAll(dir))
+	})
+
+	return dir
+}
+
+func createTestConfigWithSingleRoute() *GatewayConfig {
+	testConf := &GatewayConfig{
+		Connections: Connection{
+			Routes: []Routes{
+				{
+					Path:     "products",
+					Url:      "http://services:9001",
+					Auth:     false,
+					ZoneName: "",
+					RateLimit: RateLimit{
+						Zone: 10,
+						Rate: 5,
+					},
+				},
+			},
+		},
+	}
+
+	return testConf
+}
+
+func createTestConfigWithMultipleRoutes() *GatewayConfig {
+	testConf := &GatewayConfig{
+		Connections: Connection{
+			Routes: []Routes{
+				{
+					Path:     "products",
+					Url:      "http://services:9001",
+					Auth:     false,
+					ZoneName: "",
+					RateLimit: RateLimit{
+						Zone: 10,
+						Rate: 5,
+					},
+				},
+				{
+					Path:     "orders",
+					Url:      "http://services:9002",
+					Auth:     false,
+					ZoneName: "",
+					RateLimit: RateLimit{
+						Zone: 10,
+						Rate: 5,
+					},
+				},
+			},
+		},
+	}
+
+	return testConf
+}
+
+type configTest struct {
+	name     string
+	input    string
+	expected *GatewayConfig
+	willFail bool
+}
+
+func TestLoadAndValidateGatewayConf(t *testing.T) {
+	emptyConf := &GatewayConfig{}
+	singleRouteConf := createTestConfigWithSingleRoute()
+	multiRouteConf := createTestConfigWithMultipleRoutes()
+
+	tests := []configTest{
+		{
+			name:     "Empty string as input",
+			input:    "",
+			expected: emptyConf,
+			willFail: false,
+		},
+		{
+			name:     "Only comments as input",
+			input:    "# this is a comment\n# another comment\n   \n",
+			expected: emptyConf,
+			willFail: false,
+		},
+		{
+			name:     "Valid Input with single route",
+			input:    "connections:\n  routes:\n    - path: products\n      url: http://services:9001\n      rate-limit:\n        zone: 10\n        rate: 5\n      auth: false",
+			expected: singleRouteConf,
+			willFail: false,
+		},
+		{
+			name:     "Valid Input with multiple routes",
+			input:    "connections:\n  routes:\n    - path: products\n      url: http://services:9001\n      rate-limit:\n        zone: 10\n        rate: 5\n      auth: false\n\n    - path: orders\n      url: http://services:9002\n      rate-limit:\n        zone: 10\n        rate: 5\n      auth: false",
+			expected: multiRouteConf,
+			willFail: false,
+		},
+		{
+			name:     "Invalid Input",
+			input:    "connections:\n  routes:\n  - path: [invalid yaml",
+			expected: emptyConf,
+			willFail: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg, err := loadAndValidateGatewayConf(tt.input)
+
+			if tt.willFail {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tt.expected, cfg)
+			}
+
+		})
+	}
+}
+
+type (
+	templateDataTest struct {
+		name     string
+		input    expectedTemplateData
+		expected TemplateData
+	}
+
+	expectedTemplateData struct {
+		username string
+		gw       *GatewayConfig
+	}
+)
+
+func TestBuildTemplateData(t *testing.T) {
+	emptyConf := &GatewayConfig{}
+	singleRouteConf := createTestConfigWithSingleRoute()
+
+	tests := []templateDataTest{
+		{
+			name: "Gateway config is empty",
+			input: expectedTemplateData{
+				username: "janedoe",
+				gw:       emptyConf,
+			},
+			expected: TemplateData{
+				Username:    "janedoe",
+				Connections: Connection{},
+			},
+		},
+		{
+			name: "Gateway config is not empty",
+			input: expectedTemplateData{
+				username: "janedoe",
+				gw:       singleRouteConf,
+			},
+			expected: TemplateData{
+				Username: "janedoe",
+				Connections: Connection{
+					Routes: []Routes{
+						{
+							Path:     "products",
+							Url:      "http://services:9001",
+							Auth:     false,
+							ZoneName: "products",
+							RateLimit: RateLimit{
+								Zone: 10,
+								Rate: 5,
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			data := buildTemplateData(tt.input.username, tt.input.gw)
+			require.Equal(t, tt.expected, data)
+		})
+	}
+}
+
+type NewConfigTest struct {
+	name     string
+	req      *http.Request
+	expected int
+}
+
+func TestLoadNewConfig(t *testing.T) {
+	emptyBody, _ := json.Marshal(ConfRequest{Content: ""})
+	payload := ConfRequest{Content: "connections:\n  routes:\n  - path: [broken yaml"}
+	b, _ := json.Marshal(payload)
+
+	tests := []NewConfigTest{
+		{
+			name:     "Method not Allowed",
+			req:      httptest.NewRequest(http.MethodGet, "/config", nil),
+			expected: http.StatusMethodNotAllowed,
+		},
+		{
+			name:     "Missing Session Cookie",
+			req:      httptest.NewRequest(http.MethodPost, "/config", bytes.NewReader(emptyBody)),
+			expected: http.StatusUnauthorized,
+		},
+		{
+			name:     "Invalid JSON body",
+			req:      httptest.NewRequest(http.MethodPost, "/config", strings.NewReader("{bad json")),
+			expected: http.StatusBadRequest,
+		},
+		{
+			name:     "Invalid content",
+			req:      httptest.NewRequest(http.MethodPost, "/config", bytes.NewReader(b)),
+			expected: http.StatusBadRequest,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.name == "Invalid JSON body" || tt.name == "Invalid content" {
+				tt.req.AddCookie(&http.Cookie{Name: "session", Value: "test-session"})
+			}
+
+			rr := httptest.NewRecorder()
+			LoadNewConfig(rr, tt.req)
+			require.Equal(t, tt.expected, rr.Code)
+		})
+	}
+}
+
+type (
+	AtomicWriteTest struct {
+		name  string
+		input AtomicTestData
+	}
+
+	AtomicTestData struct {
+		dir     string
+		file    string
+		content []byte
+	}
+)
+
+func TestAtomicWrites(t *testing.T) {
+	dir := tmpDir(t)
+
+	tests := []AtomicWriteTest{
+		{
+			name: "Valid data supplied",
+			input: AtomicTestData{
+				dir:     dir,
+				file:    "nginx.conf",
+				content: []byte("server { listen 80; }"),
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := atomicWrites(tt.input.dir, tt.input.file, tt.input.content)
+			require.NoError(t, err)
+
+			got, err := os.ReadFile(filepath.Join(dir, "nginx.conf"))
+			require.NoError(t, err)
+			require.Equal(t, tt.input.content, got)
+
+			entries, err := os.ReadDir(dir)
+			require.NoError(t, err)
+			for _, e := range entries {
+				if strings.HasPrefix(e.Name(), "nginx-") && strings.HasSuffix(e.Name(), ".conf") {
+					require.Fail(t, "temp file left behind", e.Name())
+				}
+			}
+		})
+	}
+}