[go] Honor empty ClientOptions.Env (#297)

* honor empty ClientOptions.Env

* fic nil options

Author: qmuntal

go/client.go

@@ -145,7 +145,7 @@ func NewClient(options *ClientOptions) *Client {
 		if options.LogLevel != "" {
 			opts.LogLevel = options.LogLevel
 		}
-		if len(options.Env) > 0 {
+		if options.Env != nil {
 			opts.Env = options.Env
 		}
 		if options.UseStdio != nil {
@@ -165,6 +165,11 @@ func NewClient(options *ClientOptions) *Client {
 		}
 	}
 
+	// Default Env to current environment if not set
+	if opts.Env == nil {
+		opts.Env = os.Environ()
+	}
+
 	// Check environment variable for CLI path
 	if cliPath := os.Getenv("COPILOT_CLI_PATH"); cliPath != "" {
 		opts.CLIPath = cliPath
@@ -1090,12 +1095,8 @@ func (c *Client) startCLIServer() error {
 		c.process.Dir = c.options.Cwd
 	}
 
-	// Set environment if specified, adding auth token if needed
-	if len(c.options.Env) > 0 {
-		c.process.Env = c.options.Env
-	} else {
-		c.process.Env = os.Environ()
-	}
+	// Add auth token if needed.
+	c.process.Env = c.options.Env
 	if c.options.GithubToken != "" {
 		c.process.Env = append(c.process.Env, "COPILOT_SDK_AUTH_TOKEN="+c.options.GithubToken)
 	}

go/client_test.go

@@ -3,6 +3,7 @@ package copilot
 import (
 	"os"
 	"path/filepath"
+	"reflect"
 	"regexp"
 	"testing"
 )
@@ -334,6 +335,53 @@ func TestClient_AuthOptions(t *testing.T) {
 	})
 }
 
+func TestClient_EnvOptions(t *testing.T) {
+	t.Run("should store custom environment variables", func(t *testing.T) {
+		client := NewClient(&ClientOptions{
+			Env: []string{"FOO=bar", "BAZ=qux"},
+		})
+
+		if len(client.options.Env) != 2 {
+			t.Errorf("Expected 2 environment variables, got %d", len(client.options.Env))
+		}
+		if client.options.Env[0] != "FOO=bar" {
+			t.Errorf("Expected first env var to be 'FOO=bar', got %q", client.options.Env[0])
+		}
+		if client.options.Env[1] != "BAZ=qux" {
+			t.Errorf("Expected second env var to be 'BAZ=qux', got %q", client.options.Env[1])
+		}
+	})
+
+	t.Run("should default to inherit from current process", func(t *testing.T) {
+		client := NewClient(&ClientOptions{})
+
+		if want := os.Environ(); !reflect.DeepEqual(client.options.Env, want) {
+			t.Errorf("Expected Env to be %v, got %v", want, client.options.Env)
+		}
+	})
+
+	t.Run("should default to inherit from current process with nil options", func(t *testing.T) {
+		client := NewClient(nil)
+
+		if want := os.Environ(); !reflect.DeepEqual(client.options.Env, want) {
+			t.Errorf("Expected Env to be %v, got %v", want, client.options.Env)
+		}
+	})
+
+	t.Run("should allow empty environment", func(t *testing.T) {
+		client := NewClient(&ClientOptions{
+			Env: []string{},
+		})
+
+		if client.options.Env == nil {
+			t.Error("Expected Env to be non-nil empty slice")
+		}
+		if len(client.options.Env) != 0 {
+			t.Errorf("Expected 0 environment variables, got %d", len(client.options.Env))
+		}
+	})
+}
+
 func findCLIPathForTest() string {
 	abs, _ := filepath.Abs("../nodejs/node_modules/@github/copilot/index.js")
 	if fileExistsForTest(abs) {

go/types.go

@@ -34,7 +34,11 @@ type ClientOptions struct {
 	// AutoRestart automatically restarts the CLI server if it crashes (default: true).
 	// Use Bool(false) to disable.
 	AutoRestart *bool
-	// Env is the environment variables for the CLI process (default: inherits from current process)
+	// Env is the environment variables for the CLI process (default: inherits from current process).
+	// Each entry is of the form "key=value".
+	// If Env is nil, the new process uses the current process's environment.
+	// If Env contains duplicate environment keys, only the last value in the
+	// slice for each duplicate key is used.
 	Env []string
 	// GithubToken is the GitHub token to use for authentication.
 	// When provided, the token is passed to the CLI server via environment variable.