refactor config to use functional options pattern

5 files changed, 53 insertions, 27 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index cb144f3..988315a 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -24,7 +24,7 @@ type Config struct {
 	SMTPServer      string `json:"SMTPServer,omitempty"`
 }
 
-func New(configFile string) (Config, error) {
+func NewFromConfigFile(configFile string) (Config, error) {
 	var conf Config
 
 	file, err := os.Open(configFile)
@@ -43,14 +43,50 @@ func New(configFile string) (Config, error) {
 		return conf, err
 	}
 
-	return NewFromConfig(conf)
+	return conf.setDefaults()
 }
 
-func NewFromConfig(conf Config) (Config, error) {
-	return conf.initialize()
+func New(options ...func(*Config)) (Config, error) {
+	var conf Config
+
+	for _, opt := range options {
+		opt(&conf)
+	}
+
+	return conf.setDefaults()
+}
+
+func WithStateDir(stateDir string) func(*Config) {
+	return func(conf *Config) {
+		conf.StateDir = stateDir
+	}
+}
+
+func WithAddress(address string) func(*Config) {
+	return func(conf *Config) {
+		conf.Address = address
+	}
+}
+
+func WithNodes(nodes ...string) func(*Config) {
+	return func(conf *Config) {
+		conf.Nodes = append(conf.Nodes, nodes...)
+	}
+}
+
+func WithMyID(id string) func(*Config) {
+	return func(conf *Config) {
+		conf.MyID = id
+	}
+}
+
+func WithRelaxedMode() func(*Config) {
+	return func(conf *Config) {
+		conf.RelaxedMode = true
+	}
 }
 
-func (conf Config) initialize() (Config, error) {
+func (conf Config) setDefaults() (Config, error) {
 	if conf.LoopIntervalS == 0 {
 		conf.LoopIntervalS = 10
 	}
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index 96d4998..e24c048 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -8,7 +8,7 @@ import (
 
 func TestNodeNumber(t *testing.T) {
 	t.Parallel()
-	conf, _ := NewFromConfig(Config{Nodes: []string{"localhost:1234", "hamburger:4321"}})
+	conf, _ := New(WithNodes("localhost:1234", "hamburger:4321"))
 
 	num := conf.NodeNumber("localhost")
 	if num != 0 {
@@ -23,7 +23,7 @@ func TestNodeNumber(t *testing.T) {
 
 func TestIsNode(t *testing.T) {
 	t.Parallel()
-	conf, _ := NewFromConfig(Config{Nodes: []string{"localhost:1234", "hamburger:4321"}})
+	conf, _ := New(WithNodes("localhost:1234", "hamburger:4321"))
 
 	remoteAddr := "localhost:323232"
 	if !conf.IsNode(remoteAddr) {
@@ -38,7 +38,7 @@ func TestIsNode(t *testing.T) {
 
 func TestIsNodeWithLookup(t *testing.T) {
 	t.Parallel()
-	conf, _ := NewFromConfig(Config{Nodes: []string{"localhost:1234", "hamburger:4321"}})
+	conf, _ := New(WithNodes("localhost:1234", "hamburger:4321"))
 
 	lookupIP := func(addr string) ([]net.IP, error) {
 		switch addr {
diff --git a/internal/quorum/quorum_test.go b/internal/quorum/quorum_test.go
index 3ae87c6..5bf6834 100644
--- a/internal/quorum/quorum_test.go
+++ b/internal/quorum/quorum_test.go
@@ -13,9 +13,7 @@ var inOneHour = time.Now().Add(1 * time.Hour)
 func TestScore(t *testing.T) {
 	t.Parallel()
 
-	conf, _ := config.NewFromConfig(
-		config.Config{Nodes: []string{"foo:1234", "bar:4321", "baz:3444"}},
-	)
+	conf, _ := config.New(config.WithNodes("foo:1234", "bar:4321", "baz:3444"))
 	quo := New(conf)
 
 	vote1, _ := vote.New(conf, []string{"foo", "bar"})
@@ -69,9 +67,7 @@ func TestTieScore(t *testing.T) {
 
 	t.Run("First tie score test", func(t *testing.T) {
 		// If it is a tie, the first particpant (here: "foo") will win.
-		conf, _ := config.NewFromConfig(
-			config.Config{Nodes: []string{"foo:1234", "bar:4321", "baz:3444"}},
-		)
+		conf, _ := config.New(config.WithNodes("foo:1234", "bar:4321", "baz:3444"))
 		quo := New(conf)
 
 		addVotes(conf, quo)
@@ -92,9 +88,7 @@ func TestTieScore(t *testing.T) {
 
 	t.Run("Second tie score test", func(t *testing.T) {
 		// If it is a tie, the first particpant (here: "bar") will win.
-		conf, _ := config.NewFromConfig(
-			config.Config{Nodes: []string{"bar:1234", "foo:4321", "baz:3444"}},
-		)
+		conf, _ := config.New(config.WithNodes("bar:1234", "foo:4321", "baz:3444"))
 		quo := New(conf)
 
 		addVotes(conf, quo)
@@ -115,9 +109,7 @@ func TestTieScore(t *testing.T) {
 }
 
 func TestExpire(t *testing.T) {
-	conf, _ := config.NewFromConfig(
-		config.Config{Nodes: []string{"foo:1234", "bar:4321", "bay:2212"}},
-	)
+	conf, _ := config.New(config.WithNodes("foo:1234", "bar:4321", "bay:2212"))
 	quo := New(conf)
 
 	vote1, _ := vote.New(conf, []string{"bar", "baz", "bay"})
@@ -149,9 +141,7 @@ func TestExpire(t *testing.T) {
 }
 
 func TestLiveNodes(t *testing.T) {
-	conf, _ := config.NewFromConfig(
-		config.Config{Nodes: []string{"foo:1234", "bay:4321"}},
-	)
+	conf, _ := config.New(config.WithNodes("foo:1234", "bay:4321"))
 	quo := New(conf)
 
 	vote1, _ := vote.New(conf, []string{"bar", "baz", "bay"})
diff --git a/internal/run.go b/internal/run.go
index 961df14..7a51f6c 100644
--- a/internal/run.go
+++ b/internal/run.go
@@ -10,7 +10,7 @@ import (
 )
 
 func Run(ctx context.Context, configFile string, loopIntervalS int64) error {
-	conf, err := config.New(configFile)
+	conf, err := config.NewFromConfigFile(configFile)
 	if err != nil {
 		return err
 	}
diff --git a/internal/vote/vote_test.go b/internal/vote/vote_test.go
index a546a2b..f1221b2 100644
--- a/internal/vote/vote_test.go
+++ b/internal/vote/vote_test.go
@@ -10,7 +10,7 @@ import (
 func TestVote(t *testing.T) {
 	t.Parallel()
 
-	conf, _ := config.NewFromConfig(config.Config{MyID: "foo.zone"})
+	conf, _ := config.New(config.WithMyID("foo.zone"))
 	v, _ := New(conf, []string{"foo", "bar", "baz", "bay"})
 
 	if v.FromID != "foo.zone" {
@@ -33,7 +33,7 @@ func TestVote(t *testing.T) {
 func TestVoteExpiry(t *testing.T) {
 	t.Parallel()
 
-	conf, _ := config.NewFromConfig(config.Config{MyID: "foo.zone"})
+	conf, _ := config.New(config.WithMyID("foo.zone"))
 	v, _ := New(conf, []string{"foo", "bar", "baz", "bay"})
 
 	// Set expiry 1h into the future
@@ -52,7 +52,7 @@ func TestVoteExpiry(t *testing.T) {
 func TestMarshalling(t *testing.T) {
 	t.Parallel()
 
-	conf, _ := config.NewFromConfig(config.Config{MyID: "foo.zone"})
+	conf, _ := config.New(config.WithMyID("foo.zone"))
 	v, _ := New(conf, []string{"foo", "bar", "baz", "bay"})
 
 	jsonStr, err := v.ToJSON()