feat: complete API-driven projects with infrastructure and business acceptance

database/configOverlay_test.go

@@ -0,0 +1,35 @@
+package database
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestApplyEnvPreservesFilePoolAndHidesDSN(t *testing.T) {
+	cfg := DefaultConfig()
+	cfg.MaxOpenConns = 3
+	cfg.MaxIdleConns = 1
+	cfg.PingTimeout = time.Second
+	t.Setenv("OMNI_TEST_DSN", "user:secret@tcp(localhost:3306)/test")
+	t.Setenv("OMNI_TEST_MAX_IDLE_CONNS", "0")
+	got, err := ApplyEnv(cfg, "OMNI_TEST_")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.MaxOpenConns != 3 || got.MaxIdleConns != 0 || got.PingTimeout != time.Second {
+		t.Fatalf("lost file defaults: %+v", got)
+	}
+	data, err := json.Marshal(got)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(string(data), "secret") || !strings.Contains(string(data), "maxOpenConns") {
+		t.Fatalf("unsafe config encoding: %s", data)
+	}
+	t.Setenv("OMNI_TEST_MAX_OPEN_CONNS", "bad")
+	if _, err = ApplyEnv(cfg, "OMNI_TEST_"); err == nil {
+		t.Fatal("invalid override accepted")
+	}
+}

database/database.go

@@ -14,13 +14,13 @@ import (
 )
 
 type Config struct {
-	Driver          string
-	DSN             string
-	MaxOpenConns    int
-	MaxIdleConns    int
-	ConnMaxLifetime time.Duration
-	ConnMaxIdleTime time.Duration
-	PingTimeout     time.Duration
+	Driver          string        `json:"driver"`
+	DSN             string        `json:"-"`
+	MaxOpenConns    int           `json:"maxOpenConns"`
+	MaxIdleConns    int           `json:"maxIdleConns"`
+	ConnMaxLifetime time.Duration `json:"connMaxLifetime"`
+	ConnMaxIdleTime time.Duration `json:"connMaxIdleTime"`
+	PingTimeout     time.Duration `json:"pingTimeout"`
 }
 
 func DefaultConfig() Config {
@@ -35,16 +35,25 @@ func DefaultConfig() Config {
 
 // ConfigFromEnv reads GO_OMNI_DB_* style settings. DSN is required.
 func ConfigFromEnv(prefix string) (Config, error) {
+	return ApplyEnv(DefaultConfig(), prefix)
+}
+
+// ApplyEnv overlays nonempty environment settings on file/default configuration.
+// DSN is environment-only when Config is decoded from JSON or YAML.
+func ApplyEnv(cfg Config, prefix string) (Config, error) {
 	prefix = strings.TrimSpace(prefix)
 	if prefix == "" {
 		prefix = "GO_OMNI_DB_"
 	}
-	cfg := DefaultConfig()
-	cfg.Driver = strings.TrimSpace(os.Getenv(prefix + "DRIVER"))
+	if value := strings.TrimSpace(os.Getenv(prefix + "DRIVER")); value != "" {
+		cfg.Driver = value
+	}
 	if cfg.Driver == "" {
 		cfg.Driver = "mysql"
 	}
-	cfg.DSN = strings.TrimSpace(os.Getenv(prefix + "DSN"))
+	if value := strings.TrimSpace(os.Getenv(prefix + "DSN")); value != "" {
+		cfg.DSN = value
+	}
 	if cfg.DSN == "" {
 		return Config{}, fmt.Errorf("%sDSN is required", prefix)
 	}