Add test case for LoadConfig

config/config_test.go

@@ -1,9 +1,29 @@
 package config
 
 import (
+	"io"
+	"log"
+	"os"
 	"testing"
 )
 
+/*
+No test case for GetToken yet due to token_manager dependency
+Mocking token_manager isn't fun
+
+TestLoadConfig focuses on verifying main functionality (e.g. fallback when invalid input),
+and *shouldn't* need exhaustive scenarios
+*/
+
+// setupTestLogger sets up a logger that discards output and returns a function to restore the original logger
+func setupTestLogger() func() {
+	originalLogger := log.Default()
+	log.SetOutput(io.Discard)
+	return func() {
+		log.SetOutput(originalLogger.Writer())
+	}
+}
+
 // TestParseRevision is a test function that verifies the behavior of the parseRevision function.
 func TestParseRevision(t *testing.T) {
 	tests := []struct {
@@ -75,3 +95,116 @@ func TestValidateURL(t *testing.T) {
 		})
 	}
 }
+
+// TestLoadConfig is a test function that verifies the behavior of the LoadConfig function.
+func TestLoadConfig(t *testing.T) {
+	// Helper function to set environment variables
+	setEnv := func(env map[string]string) {
+		for k, v := range env {
+			os.Setenv(k, v)
+		}
+	}
+
+	// Helper function to unset environment variables
+	unsetEnv := func(env map[string]string) {
+		for k := range env {
+			os.Unsetenv(k)
+		}
+	}
+
+	tests := []struct {
+		name    string            // Description of the test case
+		env     map[string]string // Name of the environment variable and its value
+		wantErr bool              // Whether an error is expected
+	}{
+		{
+			name: "Valid configuration",
+			env: map[string]string{
+				"PIXIVFE_HOST":  "localhost",
+				"PIXIVFE_PORT":  "8282",
+				"PIXIVFE_TOKEN": "token1,token2",
+			},
+			wantErr: false,
+		},
+		{
+			name: "Missing required PIXIVFE_TOKEN",
+			env: map[string]string{
+				"PIXIVFE_HOST":       "localhost",
+				"PIXIVFE_PORT":       "8282",
+				"PIXIVFE_IMAGEPROXY": "https://imageproxy.test",
+			},
+			wantErr: true,
+		},
+		{
+			name: "Invalid PIXIVFE_IMAGEPROXY",
+			env: map[string]string{
+				"PIXIVFE_HOST":       "localhost",
+				"PIXIVFE_PORT":       "8282",
+				"PIXIVFE_TOKEN":      "token1,token2",
+				"PIXIVFE_IMAGEPROXY": "invalidimageproxy-test",
+			},
+			wantErr: false, // Should not return an error, but use fallback BuiltinProxyUrl
+		},
+		{
+			name: "Invalid PIXIVFE_TOKEN_LOAD_BALANCING",
+			env: map[string]string{
+				"PIXIVFE_HOST":                 "localhost",
+				"PIXIVFE_PORT":                 "8282",
+				"PIXIVFE_TOKEN":                "token1,token2",
+				"PIXIVFE_TOKEN_LOAD_BALANCING": "invalid-load-balancing-method",
+			},
+			wantErr: false, // Should not return an error, but use fallback round-robin
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Set up test logger
+			restoreLogger := setupTestLogger()
+			defer restoreLogger()
+
+			// Set up environment
+			setEnv(tt.env)
+			defer unsetEnv(tt.env)
+
+			// Create a new ServerConfig instance
+			config := &ServerConfig{}
+
+			// Call LoadConfig
+			err := config.LoadConfig()
+
+			// Check for errors
+			if (err != nil) != tt.wantErr {
+				t.Errorf("LoadConfig() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+			if !tt.wantErr {
+				// Test whether config fields were set correctly
+				if config.Host != tt.env["PIXIVFE_HOST"] {
+					t.Errorf("LoadConfig() Host = %v, want %v", config.Host, tt.env["PIXIVFE_HOST"])
+				}
+
+				if config.Port != tt.env["PIXIVFE_PORT"] {
+					t.Errorf("LoadConfig() Port = %v, want %v", config.Port, tt.env["PIXIVFE_PORT"])
+				}
+
+				if len(config.Token) != 2 && tt.env["PIXIVFE_TOKEN"] == "token1,token2" {
+					t.Errorf("LoadConfig() Token count = %v, want 2", len(config.Token))
+				}
+
+				if config.TokenManager == nil {
+					t.Error("LoadConfig() TokenManager is nil")
+				}
+
+				if config.ProxyServer.String() == "" {
+					t.Error("LoadConfig() ProxyServer is empty")
+				}
+
+				if config.TokenLoadBalancing == "" {
+					t.Error("LoadConfig() TokenLoadBalancing is empty")
+				}
+			}
+		})
+	}
+}