test: refactor TestTopics function for improved structure and readability

Author: fabianoflorentino

internal/agrupamento_de_dados/topic_test.go

@@ -3,27 +3,88 @@ package agrupamento_de_dados
 import (
 	"os"
 	"testing"
-)
 
-func init() {
-	rootDir = "./"
-}
+	"github.com/fabianoflorentino/aprendago/pkg/topic"
+)
 
 func TestTopics(t *testing.T) {
-	oldStdout := os.Stdout
-	defer func() { os.Stdout = oldStdout }()
+	os.Setenv("GOENV", "test")
 
-	nullFile, err := os.OpenFile(os.DevNull, os.O_WRONLY, 0)
-	if err != nil {
-		t.Fatalf("failed to open null device: %v", err)
+	tt := topic.New()
+
+	list := []string{
+		sliceLiteralComposta,
+		sliceForRange,
+		sliceFatiandoOuDeletando,
+		sliceAnexando,
+		sliceMake,
+		sliceMultiDimensional,
+		sliceSurpresaArraySubjacente,
+		mapsIntroducao,
+		mapsRangeEDeletando,
 	}
-	defer nullFile.Close()
 
-	os.Stdout = nullFile
+	t.Run("TestRootDirValidation", func(t *testing.T) {
+		if rootDir != "internal/agrupamento_de_dados" {
+			t.Errorf("Expected rootDir to be 'internal/agrupamento_de_dados', got '%s'", rootDir)
+		}
+	})
 
-	Topics()
+	t.Run("TestListOfTopicsWithValidInput", func(t *testing.T) {
+		expectedLength := 9
+		topics := tt.ListOfTopics(list, expectedLength)
+		if len(topics) != expectedLength {
+			t.Errorf("Expected %d topics, got %d", expectedLength, len(topics))
+		}
 
-	if err != nil {
-		t.Errorf("Topics() failed: %v", err)
-	}
+		expectedTopics := []string{
+			sliceLiteralComposta,
+			sliceForRange,
+			sliceFatiandoOuDeletando,
+			sliceAnexando,
+			sliceMake,
+			sliceMultiDimensional,
+			sliceSurpresaArraySubjacente,
+			mapsIntroducao,
+			mapsRangeEDeletando,
+		}
+
+		for i, topic := range expectedTopics {
+			if topics[i] != topic {
+				t.Errorf("Expected topic at index %d to be %s, got %s", i, topic, topics[i])
+			}
+		}
+	})
+
+	t.Run("TestListOfTopicsWithLimitGreaterThanListSize", func(t *testing.T) {
+		limit := 10
+		topics := tt.ListOfTopics(list, limit)
+		if len(topics) != len(list) {
+			t.Errorf("Expected %d topics, got %d", len(list), len(topics))
+		}
+	})
+
+	t.Run("TestListOfTopicsWithZeroLimit", func(t *testing.T) {
+		limit := 0
+		topics := tt.ListOfTopics(list, limit)
+		if len(topics) != 0 {
+			t.Errorf("Expected 0 topics, got %d", len(topics))
+		}
+	})
+
+	t.Run("TestListOfTopicsWithNegativeLimit", func(t *testing.T) {
+		limit := -5
+		topics := tt.ListOfTopics(list, limit)
+		if len(topics) != 0 {
+			t.Errorf("Expected 0 topics, got %d", len(topics))
+		}
+	})
+
+	t.Run("TestListOfTopicsWithEmptyList", func(t *testing.T) {
+		emptyList := []string{}
+		topics := tt.ListOfTopics(emptyList, 5)
+		if len(topics) != 0 {
+			t.Errorf("Expected 0 topics for empty list, got %d", len(topics))
+		}
+	})
 }