Add entrypoint to the program

internal/testutils/multilines.go

@@ -0,0 +1,31 @@
+package testutils
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ExpectMultiLineString compares two multi-line strings and report the difference
+func ExpectMultiLineString(expected, actual string) error {
+	expectedLines := strings.Split(expected, "\n")
+	actualLines := strings.Split(actual, "\n")
+
+	numberOfComparableLines := len(expectedLines)
+	if len(actualLines) < numberOfComparableLines {
+		numberOfComparableLines = len(actualLines)
+	}
+
+	for i := 0; i < numberOfComparableLines; i++ {
+		if expectedLines[i] != actualLines[i] {
+			return fmt.Errorf("On line %d\nExpected: %v\nReceived: %v", i+1, expectedLines[i], actualLines[i])
+		}
+	}
+
+	if len(expectedLines) < len(actualLines) {
+		return fmt.Errorf("Unexpected lines:\n%s", strings.Join(actualLines[len(expectedLines):], "\n"))
+	} else if len(expectedLines) > len(actualLines) {
+		return fmt.Errorf("Missing lines:\n%s", strings.Join(expectedLines[len(actualLines):], "\n"))
+	}
+
+	return nil
+}

internal/testutils/multilines_test.go

@@ -0,0 +1,72 @@
+package testutils_test
+
+import (
+	"testing"
+
+	"github.com/sunboyy/repogen/internal/testutils"
+)
+
+func TestExpectMultiLineString(t *testing.T) {
+	t.Run("same string should return nil", func(t *testing.T) {
+		text := `  Hello world
+			this is a test text  `
+
+		err := testutils.ExpectMultiLineString(text, text)
+
+		if err != nil {
+			t.Errorf("Expected = <nil>\nReceived = %s", err.Error())
+		}
+	})
+
+	t.Run("different string with same number of lines", func(t *testing.T) {
+		expectedText := `  Hello world
+this is an expected text
+how are you?`
+		actualText := `  Hello world
+this is a real text
+How are you?`
+
+		err := testutils.ExpectMultiLineString(expectedText, actualText)
+
+		expectedError := "On line 2\nExpected: this is an expected text\nReceived: this is a real text"
+		if err == nil || err.Error() != expectedError {
+			t.Errorf("Expected = %s\nReceived = %s", expectedError, err.Error())
+		}
+	})
+
+	t.Run("expected text longer than actual text", func(t *testing.T) {
+		expectedText := `  Hello world
+this is an expected text
+how are you?
+I'm fine...
+Thank you...`
+		actualText := `  Hello world
+this is an expected text
+how are you?`
+
+		err := testutils.ExpectMultiLineString(expectedText, actualText)
+
+		expectedError := "Missing lines:\nI'm fine...\nThank you..."
+		if err == nil || err.Error() != expectedError {
+			t.Errorf("Expected = %s\nReceived = %s", expectedError, err.Error())
+		}
+	})
+
+	t.Run("actual text longer than expected text", func(t *testing.T) {
+		expectedText := `  Hello world
+this is an expected text
+how are you?`
+		actualText := `  Hello world
+this is an expected text
+how are you?
+I'm fine...
+Thank you...`
+
+		err := testutils.ExpectMultiLineString(expectedText, actualText)
+
+		expectedError := "Unexpected lines:\nI'm fine...\nThank you..."
+		if err == nil || err.Error() != expectedError {
+			t.Errorf("Expected = %s\nReceived = %s", expectedError, err.Error())
+		}
+	})
+}