Add some test coverage for Config

internal/config_test.go

@@ -0,0 +1,43 @@
+package internal
+
+import (
+ "testing"
+ "time"
+
+ "github.com/stretchr/testify/assert"
+ "github.com/stretchr/testify/require"
+)
+
+func TestConfig_defaults(t *testing.T) {
+ usingProgramArgs(t, "thruster", "echo", "hello")
+
+ c, err := NewConfig()
+ require.NoError(t, err)
+
+ assert.Equal(t, 3000, c.TargetPort)
+ assert.Equal(t, "echo", c.UpstreamCommand)
+ assert.Equal(t, defaultCacheSize, c.CacheSizeBytes)
+}
+
+func TestConfig_override_defaults_with_env_vars(t *testing.T) {
+ usingProgramArgs(t, "thruster", "echo", "hello")
+ usingEnvVar(t, "TARGET_PORT", "4000")
+ usingEnvVar(t, "CACHE_SIZE", "256")
+ usingEnvVar(t, "HTTP_READ_TIMEOUT", "30")
+ usingEnvVar(t, "X_SENDFILE_ENABLED", "0")
+
+ c, err := NewConfig()
+ require.NoError(t, err)
+
+ assert.Equal(t, 4000, c.TargetPort)
+ assert.Equal(t, 256, c.CacheSizeBytes)
+ assert.Equal(t, 30*time.Second, c.HttpReadTimeout)
+ assert.Equal(t, false, c.XSendfileEnabled)
+}
+
+func TestConfig_return_error_when_no_upstream_command(t *testing.T) {
+ usingProgramArgs(t, "thruster")
+
+ _, err := NewConfig()
+ require.Error(t, err)
+}

internal/testing.go

@@ -3,6 +3,7 @@ package internal
 import (
  "os"
  "path"
+ "testing"
 )
 
 func fixturePath(name string) string {
@@ -18,3 +19,25 @@ func fixtureLength(name string) int64 {
  info, _ := os.Stat(fixturePath(name))
  return info.Size()
 }
+
+func usingEnvVar(t *testing.T, key, value string) {
+ old, found := os.LookupEnv(key)
+ os.Setenv(key, value)
+
+ t.Cleanup(func() {
+ if found {
+ os.Setenv(key, old)
+ } else {
+ os.Unsetenv(key)
+ }
+ })
+}
+
+func usingProgramArgs(t *testing.T, args ...string) {
+ old := os.Args
+ os.Args = args
+
+ t.Cleanup(func() {
+ os.Args = old
+ })
+}