feat: add Nushell support (#389)

Implements #207

README.md

@@ -55,6 +55,9 @@ if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force
 #    Or Install cmder: https://github.com/cmderdev/cmder/releases
 # 2. Find script path: clink info | findstr scripts
 # 3. copy internal/shell/clink_vfox.lua to script path
+
+# For Nushell:
+vfox activate nushell | save --append $nu.config-path
 ```
 
 > Remember to restart your shell to apply the changes.

cmd/commands/env.go

@@ -126,7 +126,7 @@ func envFlag(ctx *cli.Context) error {
 		return err
 	}
 
-	if len(sdkEnvs) == 0 {
+	if len(sdkEnvs) == 0 && shellName != "nushell" {
 		return nil
 	}
 

docs/guides/quick-start.md

@@ -129,6 +129,14 @@ y
 3. Restart Clink or Cmder
 :::
 
+::: details Nushell
+
+```shell
+vfox activate nushell | save --append $nu.config-path
+```
+
+:::
+
 ## 3. Add a plugin
 
 **Command**: `vfox add <plugin-name>`

internal/env/macos_env.go

@@ -24,6 +24,8 @@ import (
 	"strings"
 )
 
+const Newline = "\n"
+
 type macosEnvManager struct {
 	envMap        map[string]string
 	deletedEnvMap map[string]struct{}

internal/env/windows_env.go

@@ -30,6 +30,8 @@ import (
 	"golang.org/x/sys/windows/registry"
 )
 
+const Newline = "\r\n"
+
 type windowsEnvManager struct {
 	key registry.Key
 	// $PATH

internal/shell/nushell.go

@@ -0,0 +1,96 @@
+package shell
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/version-fox/vfox/internal/env"
+	"path/filepath"
+)
+
+type nushell struct{}
+
+var Nushell = nushell{}
+
+const nushellConfig = env.Newline +
+	"# vfox configuration" + env.Newline +
+	"export-env {" + env.Newline +
+	"  def --env updateVfoxEnvironment [] {" + env.Newline +
+	"    let envData = (^'{{.SelfPath}}' env -s nushell | from json)" + env.Newline +
+	"    load-env $envData.envsToSet" + env.Newline +
+	"    hide-env ...$envData.envsToUnset" + env.Newline +
+	"  }" + env.Newline +
+	"  $env.config = ($env.config | upsert hooks.pre_prompt {" + env.Newline +
+	"    let currentValue = ($env.config | get -i hooks.pre_prompt)" + env.Newline +
+	"    if $currentValue == null {" + env.Newline +
+	"      [{updateVfoxEnvironment}]" + env.Newline +
+	"    } else {" + env.Newline +
+	"      $currentValue | append {updateVfoxEnvironment}" + env.Newline +
+	"    }" + env.Newline +
+	"  })" + env.Newline +
+	"  $env.__VFOX_SHELL = 'nushell'" + env.Newline +
+	"  $env.__VFOX_PID = $nu.pid" + env.Newline +
+	"  ^'{{.SelfPath}}' env --cleanup | ignore" + env.Newline +
+	"  updateVfoxEnvironment" + env.Newline +
+	"}" + env.Newline
+
+// Activate implements shell.Activate by returning a script to be placed in the Nushell configuration file. This script
+// does the following:
+//
+// 1. Sets up a [pre_prompt hook] to update the environment variables when needed.
+// 2. Initializes the __VFOX_SHELL and __VFOX_PID environment variables.
+// 3. Runs the vfox cleanup task.
+// 4. Updates the environment variables.
+//
+// [pre_prompt hook]: https://www.nushell.sh/book/hooks.html
+func (n nushell) Activate() (string, error) {
+	return nushellConfig, nil
+}
+
+// nushellExportData is used to create a JSON representation of the environment variables to be set and unset.
+type nushellExportData struct {
+	EnvsToSet   map[string]any `json:"envsToSet"`
+	EnvsToUnset []string       `json:"envsToUnset"`
+}
+
+// Export implements shell.Export by creating a JSON representation of the environment variables to be set and unset.
+// Nushell can then convert this JSON string to a [record] using the [from json] command, so it can load and unload the
+// environment variables using the [load-env] and [hide-env] commands.
+//
+// This approach is required for Nushell because it does not support eval-like functionality. For more background
+// information on this, see the article [How Nushell Code Gets Run].
+//
+// [record]: https://www.nushell.sh/lang-guide/chapters/types/basic_types/record.html
+// [from json]: https://www.nushell.sh/commands/docs/from_json.html
+// [load-env]: https://www.nushell.sh/commands/docs/load-env.html
+// [hide-env]: https://www.nushell.sh/commands/docs/hide-env.html
+// [How Nushell Code Gets Run]: https://www.nushell.sh/book/how_nushell_code_gets_run.html
+func (n nushell) Export(envs env.Vars) string {
+	exportData := nushellExportData{
+		EnvsToSet:   make(map[string]any),
+		EnvsToUnset: make([]string, 0),
+	}
+
+	for key, value := range envs {
+		if key == "PATH" { // Convert from string to list.
+			if value == nil {
+				value = new(string)
+			}
+			pathEntries := filepath.SplitList(*value)
+			exportData.EnvsToSet[key] = pathEntries
+		} else {
+			if value == nil {
+				exportData.EnvsToUnset = append(exportData.EnvsToUnset, key)
+			} else {
+				exportData.EnvsToSet[key] = *value
+			}
+		}
+	}
+
+	exportJson, err := json.Marshal(exportData)
+	if err != nil {
+		fmt.Printf("Failed to marshal export data: %s\n", err)
+		return ""
+	}
+
+	return string(exportJson)
+}

internal/shell/nushell_test.go

@@ -0,0 +1,175 @@
+package shell
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/version-fox/vfox/internal/env"
+	"os"
+	"reflect"
+	"runtime"
+	"slices"
+	"testing"
+	"text/template"
+)
+
+func TestActivate(t *testing.T) {
+	var newline string
+	if runtime.GOOS == "windows" {
+		newline = "\r\n"
+	} else {
+		newline = "\n"
+	}
+	selfPath := "/path/to/vfox"
+	want := newline +
+		"# vfox configuration" + newline +
+		"export-env {" + newline +
+		"  def --env updateVfoxEnvironment [] {" + newline +
+		"    let envData = (^'" + selfPath + "' env -s nushell | from json)" + newline +
+		"    load-env $envData.envsToSet" + newline +
+		"    hide-env ...$envData.envsToUnset" + newline +
+		"  }" + newline +
+		"  $env.config = ($env.config | upsert hooks.pre_prompt {" + newline +
+		"    let currentValue = ($env.config | get -i hooks.pre_prompt)" + newline +
+		"    if $currentValue == null {" + newline +
+		"      [{updateVfoxEnvironment}]" + newline +
+		"    } else {" + newline +
+		"      $currentValue | append {updateVfoxEnvironment}" + newline +
+		"    }" + newline +
+		"  })" + newline +
+		"  $env.__VFOX_SHELL = 'nushell'" + newline +
+		"  $env.__VFOX_PID = $nu.pid" + newline +
+		"  ^'" + selfPath + "' env --cleanup | ignore" + newline +
+		"  updateVfoxEnvironment" + newline +
+		"}" + newline
+
+	n := nushell{}
+	gotTemplate, err := n.Activate()
+
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+		return
+	}
+
+	parsedTemplate, err := template.New("activate").Parse(gotTemplate)
+	if err != nil {
+		t.Errorf("Unexpected error parsing template: %v", err)
+		return
+	}
+
+	var buffer bytes.Buffer
+	err = parsedTemplate.Execute(&buffer, struct{ SelfPath string }{selfPath})
+	if err != nil {
+		t.Errorf("Unexpected error executing template: %v", err)
+		return
+	}
+
+	got := buffer.String()
+	if got != want {
+		t.Errorf("Output mismatch:\n\ngot=\n%v\n\nwant=\n%v", got, want)
+	}
+}
+
+func TestExport(t *testing.T) {
+	sep := string(os.PathListSeparator)
+
+	tests := []struct {
+		name string
+		envs env.Vars
+		want nushellExportData
+	}{
+		{
+			"Empty",
+			env.Vars{},
+			nushellExportData{
+				EnvsToSet:   make(map[string]any),
+				EnvsToUnset: make([]string, 0)},
+		},
+		{
+			"SingleEnv",
+			env.Vars{"FOO": newString("bar")},
+			nushellExportData{
+				EnvsToSet:   map[string]any{"FOO": "bar"},
+				EnvsToUnset: make([]string, 0),
+			},
+		},
+		{
+			"MultipleEnvs",
+			env.Vars{"FOO": newString("bar"), "BAZ": newString("qux")},
+			nushellExportData{
+				EnvsToSet:   map[string]any{"FOO": "bar", "BAZ": "qux"},
+				EnvsToUnset: make([]string, 0),
+			},
+		},
+		{
+			"UnsetEnv",
+			env.Vars{"FOO": nil},
+			nushellExportData{
+				EnvsToSet:   make(map[string]any),
+				EnvsToUnset: []string{"FOO"},
+			},
+		},
+		{
+			"MixedEnvs",
+			env.Vars{"FOO": newString("bar"), "BAZ": nil},
+			nushellExportData{
+				EnvsToSet:   map[string]any{"FOO": "bar"},
+				EnvsToUnset: []string{"BAZ"},
+			},
+		},
+		{
+			"MultipleUnsetEnvs",
+			env.Vars{"FOO": nil, "BAZ": nil},
+			nushellExportData{
+				EnvsToSet:   make(map[string]any),
+				EnvsToUnset: []string{"FOO", "BAZ"},
+			},
+		},
+		{
+			"PathEnv",
+			env.Vars{"PATH": newString("/path1" + sep + "/path2")},
+			nushellExportData{
+				EnvsToSet:   map[string]any{"PATH": []any{"/path1", "/path2"}},
+				EnvsToUnset: make([]string, 0),
+			},
+		},
+		{
+			"PathAndOtherEnv",
+			env.Vars{
+				"PATH": newString("/path1" + sep + "/path2" + sep + "/path3"),
+				"FOO":  newString("bar"),
+				"BAZ":  nil,
+			},
+			nushellExportData{
+				EnvsToSet:   map[string]any{"PATH": []any{"/path1", "/path2", "/path3"}, "FOO": "bar"},
+				EnvsToUnset: []string{"BAZ"},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			runExportTest(t, test.envs, test.want)
+		})
+	}
+}
+
+func runExportTest(t *testing.T, envs env.Vars, want nushellExportData) {
+	n := nushell{}
+	got := n.Export(envs)
+	var gotData nushellExportData
+	err := json.Unmarshal([]byte(got), &gotData)
+	if err != nil {
+		t.Errorf("%s: error unmarshaling export data - %v", t.Name(), err)
+		return
+	}
+
+	slices.Sort(want.EnvsToUnset)
+	slices.Sort(gotData.EnvsToUnset)
+	if !reflect.DeepEqual(gotData, want) {
+		t.Errorf("%s: export data mismatch - want %v, got %v", t.Name(), want, gotData)
+	}
+}
+
+func newString(s string) *string {
+	return &s
+}

internal/shell/shell.go

@@ -23,7 +23,12 @@ import (
 )
 
 type Shell interface {
+	// Activate generates a shell script to be placed in the shell's configuration file, which will set up initial
+	// environment variables and set a hook to update the environment variables when needed.
 	Activate() (string, error)
+
+	// Export generates a string that can be used by the shell to set or unset the given environment variables. (The
+	// input specifies environment variables to be unset by giving them a nil value.)
 	Export(envs env.Vars) string
 }
 
@@ -39,7 +44,8 @@ func NewShell(name string) Shell {
 		return Fish
 	case "clink":
 		return Clink
+	case "nushell":
+		return Nushell
 	}
 	return nil
-
 }