feat: change wand file via arg or env var

README.md

@@ -114,6 +114,18 @@ wand test --help
 
 The first config file found is used.
 
+You can override config discovery with an explicit path:
+
+```bash
+# via flag
+wand --wand-file ./other-config.yml build
+
+# via environment variable
+WAND_FILE=./other-config.yml wand build
+```
+
+The `--wand-file` flag takes precedence over `WAND_FILE`.
+
 ---
 
 ## 📖 Config Reference

cmd/config.go

@@ -87,10 +87,16 @@ type rawConfig struct {
 	Commands  map[string]Command `yaml:",inline"`
 }
 
-func loadConfig() (*Config, map[string]Command, error) {
-	configPath, err := findConfigFile()
-	if err != nil {
-		return nil, nil, err
+func loadConfig(explicitPath string) (*Config, map[string]Command, error) {
+	var configPath string
+	var err error
+	if explicitPath != "" {
+		configPath = explicitPath
+	} else {
+		configPath, err = findConfigFile()
+		if err != nil {
+			return nil, nil, err
+		}
 	}
 
 	data, err := os.ReadFile(configPath)

cmd/config_test.go

@@ -115,7 +115,7 @@ build:
   cmd: go build
 `)
 
-	cfg, commands, err := loadConfig()
+	cfg, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -154,7 +154,7 @@ parent:
           cmd: echo grandchild
 `)
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -185,7 +185,7 @@ main:
   cmd: echo test
 `)
 
-	cfg, commands, err := loadConfig()
+	cfg, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -212,7 +212,7 @@ main:
   cmd: echo test
 `)
 
-	cfg, _, err := loadConfig()
+	cfg, _, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -239,7 +239,7 @@ main:
   cmd: echo test
 `)
 
-	cfg, _, err := loadConfig()
+	cfg, _, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -258,7 +258,7 @@ main:
     MY_VAR: hello
 `)
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -329,7 +329,7 @@ deploy:
   confirm: "Deploy to production?"
 `)
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -348,7 +348,7 @@ deploy:
   confirm: true
 `)
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -367,7 +367,7 @@ build:
   aliases: [b, compile]
 `)
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -386,7 +386,7 @@ main:
   working_dir: /tmp
 `)
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -396,6 +396,28 @@ main:
 	}
 }
 
+func TestLoadConfig_ExplicitPath(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "custom.yml")
+	err := os.WriteFile(configPath, []byte(`
+main:
+  description: from explicit
+  cmd: echo explicit
+`), 0644)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, commands, err := loadConfig(configPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if commands["main"].Description != "from explicit" {
+		t.Errorf("description = %q, want 'from explicit'", commands["main"].Description)
+	}
+}
+
 func TestLoadConfig_NoConfigFile(t *testing.T) {
 	dir := t.TempDir()
 	origDir, _ := os.Getwd()
@@ -408,7 +430,7 @@ func TestLoadConfig_NoConfigFile(t *testing.T) {
 	// Remove HOME to prevent finding a real ~/.wand.yml
 	t.Setenv("HOME", dir)
 
-	_, _, err := loadConfig()
+	_, _, err := loadConfig("")
 	if err == nil {
 		t.Error("expected error for missing config, got nil")
 	}
@@ -434,7 +456,7 @@ main:
 		viper.Reset()
 	}()
 
-	_, commands, err := loadConfig()
+	_, commands, err := loadConfig("")
 	if err != nil {
 		t.Fatal(err)
 	}

cmd/root.go

@@ -1,12 +1,16 @@
 package cmd
 
 import (
+	"os"
+	"strings"
+
 	"github.com/samber/lo"
 	"github.com/spf13/cobra"
 )
 
 func Execute() error {
-	cfg, commands, err := loadConfig()
+	configFile := resolveConfigFile()
+	cfg, commands, err := loadConfig(configFile)
 	if err != nil {
 		return err
 	}
@@ -17,6 +21,8 @@ func Execute() error {
 		SilenceErrors: true,
 	}
 
+	rootCmd.PersistentFlags().String("wand-file", "", "path to wand config file (overrides discovery)")
+
 	if main, ok := commands["main"]; ok {
 		rootCmd.Short = main.Description
 		rootCmd.Args = cobra.ArbitraryArgs
@@ -62,6 +68,19 @@ func buildCobraCommand(cfg *Config, name string, cmd Command) *cobra.Command {
 	return c
 }
 
+// resolveConfigFile extracts --wand-file from os.Args or WAND_FILE env before cobra parses.
+func resolveConfigFile() string {
+	for i, arg := range os.Args {
+		if arg == "--wand-file" && i+1 < len(os.Args) {
+			return os.Args[i+1]
+		}
+		if strings.HasPrefix(arg, "--wand-file=") {
+			return strings.TrimPrefix(arg, "--wand-file=")
+		}
+	}
+	return os.Getenv("WAND_FILE")
+}
+
 func registerFlags(c *cobra.Command, flags map[string]Flag) {
 	lo.ForEach(
 		lo.Entries(flags),

cmd/root_test.go

@@ -1,6 +1,8 @@
 package cmd
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 )
 
@@ -285,6 +287,68 @@ build:
 	}
 }
 
+func TestResolveConfigFile_Flag(t *testing.T) {
+	origArgs := setArgs("wand", "--wand-file", "/tmp/custom.yml", "build")
+	defer restoreArgs(origArgs)
+
+	got := resolveConfigFile()
+	if got != "/tmp/custom.yml" {
+		t.Errorf("resolveConfigFile() = %q, want /tmp/custom.yml", got)
+	}
+}
+
+func TestResolveConfigFile_FlagEquals(t *testing.T) {
+	origArgs := setArgs("wand", "--wand-file=/tmp/custom.yml", "build")
+	defer restoreArgs(origArgs)
+
+	got := resolveConfigFile()
+	if got != "/tmp/custom.yml" {
+		t.Errorf("resolveConfigFile() = %q, want /tmp/custom.yml", got)
+	}
+}
+
+func TestResolveConfigFile_EnvVar(t *testing.T) {
+	origArgs := setArgs("wand", "build")
+	defer restoreArgs(origArgs)
+
+	t.Setenv("WAND_FILE", "/tmp/env.yml")
+
+	got := resolveConfigFile()
+	if got != "/tmp/env.yml" {
+		t.Errorf("resolveConfigFile() = %q, want /tmp/env.yml", got)
+	}
+}
+
+func TestResolveConfigFile_FlagOverridesEnv(t *testing.T) {
+	origArgs := setArgs("wand", "--wand-file", "/tmp/flag.yml")
+	defer restoreArgs(origArgs)
+
+	t.Setenv("WAND_FILE", "/tmp/env.yml")
+
+	got := resolveConfigFile()
+	if got != "/tmp/flag.yml" {
+		t.Errorf("resolveConfigFile() = %q, want /tmp/flag.yml (flag should override env)", got)
+	}
+}
+
+func TestExecute_WithWandFileFlag(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "custom.yml")
+	_ = os.WriteFile(configPath, []byte(`
+main:
+  description: custom
+  cmd: echo custom
+`), 0644)
+
+	origArgs := setArgs("wand", "--wand-file", configPath)
+	defer restoreArgs(origArgs)
+
+	err := Execute()
+	if err != nil {
+		t.Fatalf("Execute() failed: %v", err)
+	}
+}
+
 func TestExecute_NoMain(t *testing.T) {
 	setupTestConfig(t, `
 build: