feat: add basic config loader

config_test.go

@@ -0,0 +1,168 @@
+package yourconfig_test
+
+import (
+	"testing"
+
+	"github.com/kjuulh/yourconfig"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoad(t *testing.T) {
+	t.Run("no types", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Zero(t, val)
+	})
+
+	t.Run("default tag, nothing set, no env set", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:""`
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Zero(t, val)
+	})
+
+	t.Run("default tag (required=true), nothing set, no env set, err", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"required:true"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.Error(t, err)
+		require.Zero(t, val)
+
+		assert.Equal(t, "config failed: field: SomeItem (env=SOME_ITEM) is not set and is required", err.Error())
+	})
+
+	t.Run("default tag (required=false), nothing set, no env set no error", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"required:false"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Zero(t, val)
+	})
+
+	t.Run("env tag nothing set, no env set, no error", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"SOME_ITEM"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Zero(t, val)
+	})
+
+	t.Run("default tag (required=true), nothing set, no env set, err", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"SOME_ITEM,required:true"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.Error(t, err)
+		require.Zero(t, val)
+
+		assert.Equal(t, "config failed: field: SomeItem (env=SOME_ITEM) is not set and is required", err.Error())
+	})
+
+	t.Run("default tag (required), nothing set, no env set, err", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"SOME_ITEM,required"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		val, err := yourconfig.Load[Config]()
+		require.Error(t, err)
+		require.Zero(t, val)
+
+		assert.Equal(t, "config failed: field: SomeItem (env=SOME_ITEM) is not set and is required", err.Error())
+	})
+
+	t.Run("default tag private, trying to set, err", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string
+			someOtherItem string `conf:"required:true"`
+			someBool      bool
+		}
+
+		t.Setenv("SOME_OTHER_ITEM", "unsettable")
+
+		val, err := yourconfig.Load[Config]()
+		require.Error(t, err)
+		require.Zero(t, val)
+
+		assert.Equal(t, "config failed: field: someOtherItem is not settable", err.Error())
+	})
+
+	t.Run("env tag and env set, no error", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"required:true"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		t.Setenv("SOME_ITEM", "some-item")
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Equal(t, "some-item", val.SomeItem)
+	})
+
+	t.Run("env tag (different name) and env set, no error", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"DIFFERENT_NAME,required:true"`
+			someOtherItem string
+			someBool      bool
+		}
+
+		t.Setenv("DIFFERENT_NAME", "some-item")
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Equal(t, "some-item", val.SomeItem)
+	})
+
+	t.Run("multiple env tag and env set, no error", func(t *testing.T) {
+		type Config struct {
+			SomeItem      string `conf:"required:true"`
+			SomeOtherItem string `conf:"required:true"`
+			someBool      bool
+		}
+
+		t.Setenv("SOME_ITEM", "some-item")
+		t.Setenv("SOME_OTHER_ITEM", "some-other-item")
+
+		val, err := yourconfig.Load[Config]()
+		require.NoError(t, err)
+
+		assert.Equal(t, "some-item", val.SomeItem)
+		assert.Equal(t, "some-other-item", val.SomeOtherItem)
+	})
+}