Add password generation algorithm option and corresponding tests

The password generation algorithm is now customizable via the `WithAlgorithm()` function, giving users more control over password generation. Tests have been added to 'config_test.go' to ensure correct functionality of the new option. Additionally, the variable naming in 'config.go' has been improved for better readability.

config.go

@@ -48,8 +48,8 @@ type Option func(*Config)
 
 // NewConfig creates a new Config instance and pre-fills it with sane
 // default settings. The Config is returned as pointer value
-func NewConfig(o ...Option) *Config {
-	c := &Config{
+func NewConfig(opts ...Option) *Config {
+	config := &Config{
 		MaxLength:  DefaultMaxLength,
 		MinLength:  DefaultMinLength,
 		Mode:       DefaultMode,
@@ -57,32 +57,39 @@ func NewConfig(o ...Option) *Config {
 	}
 
 	// Override defaults with optionally provided config.Option functions
-	for _, co := range o {
-		if co == nil {
+	for _, opt := range opts {
+		if opt == nil {
 			continue
 		}
-		co(c)
+		opt(config)
+	}
+	return config
+}
+
+// WithAlgorithm overrides the algorithm mode for the password generation
+func WithAlgorithm(algo Algorithm) Option {
+	return func(config *Config) {
+		config.Algorithm = algo
 	}
-	return c
 }
 
 // WithMinLength overrides the minimum password length
-func WithMinLength(l int64) Option {
-	return func(c *Config) {
-		c.MinLength = l
+func WithMinLength(length int64) Option {
+	return func(config *Config) {
+		config.MinLength = length
 	}
 }
 
 // WithMaxLength overrides the maximum password length
-func WithMaxLength(l int64) Option {
-	return func(c *Config) {
-		c.MaxLength = l
+func WithMaxLength(length int64) Option {
+	return func(config *Config) {
+		config.MaxLength = length
 	}
 }
 
-// WithNumberPass overrides the number of generated passwords setting
-func WithNumberPass(n int64) Option {
-	return func(c *Config) {
-		c.NumberPass = n
+// WithNumberPass overrides the amount of generated passwords setting
+func WithNumberPass(amount int64) Option {
+	return func(config *Config) {
+		config.NumberPass = amount
 	}
 }

config_test.go

@@ -29,6 +29,36 @@ func TestNewConfig(t *testing.T) {
 	}
 }
 
+func TestWithAlgorithm(t *testing.T) {
+	tests := []struct {
+		name string
+		algo Algorithm
+		want int
+	}{
+		{"Pronouncble passwords", AlgoPronouncable, 0},
+		{"Random passwords", AlgoRandom, 1},
+		{"Coinflip", AlgoCoinFlip, 2},
+		{"Unsupported", AlgoUnsupported, 3},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := NewConfig(WithAlgorithm(tt.algo))
+			if c == nil {
+				t.Errorf("NewConfig(WithAlgorithm()) failed, expected config pointer but got nil")
+				return
+			}
+			if c.Algorithm != tt.algo {
+				t.Errorf("NewConfig(WithAlgorithm()) failed, expected algo: %d, got: %d",
+					tt.algo, c.Algorithm)
+			}
+			if IntToAlgo(tt.want) != c.Algorithm {
+				t.Errorf("IntToAlgo() failed, expected algo: %d, got: %d",
+					tt.want, c.Algorithm)
+			}
+		})
+	}
+}
+
 func TestWithMaxLength(t *testing.T) {
 	var e int64 = 123
 	c := NewConfig(WithMaxLength(e))