feat: dotnet segment for .NET SDK display

New segment for .NET SDK version (or unsupported version) display.

Includes update for handling command execution errors so segments
can act differently based on exit codes. Using a custom error
type to make it testable rather than passing the OS error directly
to the segment.

docs/docs/segment-dotnet.md

@@ -0,0 +1,31 @@
+---
+id: dotnet
+title: Dotnet
+sidebar_label: Dotnet
+---
+
+## What
+
+Display the currently active .NET SDK version.
+
+## Sample Configuration
+
+```json
+{
+  "type": "dotnet",
+  "style": "powerline",
+  "powerline_symbol": "",
+  "foreground": "#000000",
+  "background": "#00ffff",
+  "properties": {
+    "prefix": " \uE77F "
+  }
+}
+```
+
+## Properties
+
+- display_version: `boolean` - display the active version or not; useful if all you need is an icon indicating `dotnet`
+  is present - defaults to `true`
+- unsupported_version_icon: `string` - text/icon that is displayed when the active .NET SDK version (e.g., one specified
+  by `global.json`) is not installed/supported - defaults to `\u2327` (X in a rectangle box)

docs/sidebars.js

@@ -17,6 +17,7 @@ module.exports = {
         "az",
         "battery",
         "command",
+        "dotnet",
         "environment",
         "exit",
         "git",

environment.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"errors"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"os"
@@ -26,7 +28,7 @@ type environmentInfo interface {
 	getHostName() (string, error)
 	getRuntimeGOOS() string
 	hasCommand(command string) bool
-	runCommand(command string, args ...string) string
+	runCommand(command string, args ...string) (string, error)
 	runShellCommand(shell string, command string) string
 	lastErrorCode() int
 	getArgs() *args
@@ -39,6 +41,14 @@ type environment struct {
 	cwd  string
 }
 
+type commandError struct {
+	exitCode int
+}
+
+func (e *commandError) Error() string {
+	return fmt.Sprintf("%d", e.exitCode)
+}
+
 func (env *environment) getenv(key string) string {
 	return os.Getenv(key)
 }
@@ -110,12 +120,18 @@ func (env *environment) getRuntimeGOOS() string {
 	return runtime.GOOS
 }
 
-func (env *environment) runCommand(command string, args ...string) string {
+func (env *environment) runCommand(command string, args ...string) (string, error) {
 	out, err := exec.Command(command, args...).Output()
-	if err != nil {
-		return ""
+
+	var exerr *exec.ExitError
+	if errors.As(err, &exerr) {
+		return "", &commandError{exitCode: exerr.ExitCode()}
 	}
-	return strings.TrimSpace(string(out))
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSpace(string(out)), nil
 }
 
 func (env *environment) runShellCommand(shell string, command string) string {

properties.go

@@ -20,6 +20,8 @@ const (
 	ColorBackground Property = "color_background"
 	//IgnoreFolders folders to ignore and not run the segment logic
 	IgnoreFolders Property = "ignore_folders"
+	//DisplayVersion show the version number or not
+	DisplayVersion Property = "display_version"
 )
 
 type properties struct {

segment.go

@@ -67,6 +67,8 @@ const (
 	Az SegmentType = "az"
 	//Kubectl writes the Kubernetes context we're currently in
 	Kubectl SegmentType = "kubectl"
+	//Dotnet writes which dotnet version is currently active
+	Dotnet SegmentType = "dotnet"
 	//Powerline writes it Powerline style
 	Powerline SegmentStyle = "powerline"
 	//Plain writes it without ornaments
@@ -123,6 +125,7 @@ func (segment *Segment) mapSegmentWithWriter(env environmentInfo) error {
 		EnvVar:    &envvar{},
 		Az:        &az{},
 		Kubectl:   &kubectl{},
+		Dotnet:    &dotnet{},
 	}
 	if writer, ok := functions[segment.Type]; ok {
 		props := &properties{

segment_az.go

@@ -40,7 +40,7 @@ func (a *az) enabled() bool {
 		return false
 	}
 
-	output := a.env.runCommand("az", "account", "show", "--query=[name,id]", "-o=tsv")
+	output, _ := a.env.runCommand("az", "account", "show", "--query=[name,id]", "-o=tsv")
 	if output == "" {
 		return false
 	}

segment_dotnet.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"errors"
+)
+
+type dotnet struct {
+	props              *properties
+	env                environmentInfo
+	activeVersion      string
+	unsupportedVersion bool
+}
+
+const (
+	//UnsupportedDotnetVersionIcon is displayed when the dotnet version in
+	//the current folder isn't supported by the installed dotnet SDK set.
+	UnsupportedDotnetVersionIcon Property = "unsupported_version_icon"
+)
+
+func (d *dotnet) string() string {
+	if d.unsupportedVersion {
+		return d.props.getString(UnsupportedDotnetVersionIcon, "\u2327")
+	}
+
+	if d.props.getBool(DisplayVersion, true) {
+		return d.activeVersion
+	}
+
+	return ""
+}
+
+func (d *dotnet) init(props *properties, env environmentInfo) {
+	d.props = props
+	d.env = env
+}
+
+func (d *dotnet) enabled() bool {
+	if !d.env.hasCommand("dotnet") {
+		return false
+	}
+
+	output, err := d.env.runCommand("dotnet", "--version")
+	if err == nil {
+		d.activeVersion = output
+		return true
+	}
+
+	// Exit code 145 is a special indicator that dotnet
+	// ran, but the current project config settings specify
+	// use of an SDK that isn't installed.
+	var exerr *commandError
+	if errors.As(err, &exerr) && exerr.exitCode == 145 {
+		d.unsupportedVersion = true
+		return true
+	}
+
+	return false
+}

segment_dotnet_test.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type dotnetArgs struct {
+	enabled         bool
+	version         string
+	unsupported     bool
+	unsupportedIcon string
+	displayVersion  bool
+}
+
+func bootStrapDotnetTest(args *dotnetArgs) *dotnet {
+	env := new(MockedEnvironment)
+	env.On("hasCommand", "dotnet").Return(args.enabled)
+	if args.unsupported {
+		err := &commandError{exitCode: 145}
+		env.On("runCommand", "dotnet", []string{"--version"}).Return("", err)
+	} else {
+		env.On("runCommand", "dotnet", []string{"--version"}).Return(args.version, nil)
+	}
+	props := &properties{
+		values: map[Property]interface{}{
+			DisplayVersion:               args.displayVersion,
+			UnsupportedDotnetVersionIcon: args.unsupportedIcon,
+		},
+	}
+	a := &dotnet{
+		env:   env,
+		props: props,
+	}
+	return a
+}
+
+func TestEnabledDotnetNotFound(t *testing.T) {
+	args := &dotnetArgs{
+		enabled: false,
+	}
+	dotnet := bootStrapDotnetTest(args)
+	assert.False(t, dotnet.enabled())
+}
+
+func TestDotnetVersionNotDisplayed(t *testing.T) {
+	args := &dotnetArgs{
+		enabled:        true,
+		displayVersion: false,
+		version:        "3.1.402",
+	}
+	dotnet := bootStrapDotnetTest(args)
+	assert.True(t, dotnet.enabled())
+	assert.Equal(t, "", dotnet.string())
+}
+
+func TestDotnetVersionDisplayed(t *testing.T) {
+	expected := "3.1.402"
+	args := &dotnetArgs{
+		enabled:        true,
+		displayVersion: true,
+		version:        expected,
+	}
+	dotnet := bootStrapDotnetTest(args)
+	assert.True(t, dotnet.enabled())
+	assert.Equal(t, expected, dotnet.string())
+}
+
+func TestDotnetVersionUnsupported(t *testing.T) {
+	expected := "x"
+	args := &dotnetArgs{
+		enabled:         true,
+		displayVersion:  true,
+		unsupported:     true,
+		unsupportedIcon: expected,
+	}
+	dotnet := bootStrapDotnetTest(args)
+	assert.True(t, dotnet.enabled())
+	assert.Equal(t, expected, dotnet.string())
+}

segment_git.go

@@ -101,7 +101,7 @@ func (g *git) enabled() bool {
 	if !g.env.hasCommand("git") {
 		return false
 	}
-	output := g.env.runCommand("git", "rev-parse", "--is-inside-work-tree")
+	output, _ := g.env.runCommand("git", "rev-parse", "--is-inside-work-tree")
 	return output == "true"
 }
 
@@ -183,7 +183,8 @@ func (g *git) setGitStatus() {
 
 func (g *git) getGitCommandOutput(args ...string) string {
 	args = append([]string{"-c", "core.quotepath=false", "-c", "color.status=false"}, args...)
-	return g.env.runCommand("git", args...)
+	val, _ := g.env.runCommand("git", args...)
+	return val
 }
 
 func (g *git) getGitHEADContext(ref string) string {

segment_git_test.go

@@ -18,7 +18,7 @@ func TestEnabledGitNotFound(t *testing.T) {
 func TestEnabledInWorkingDirectory(t *testing.T) {
 	env := new(MockedEnvironment)
 	env.On("hasCommand", "git").Return(true)
-	env.On("runCommand", "git", []string{"rev-parse", "--is-inside-work-tree"}).Return("true")
+	env.On("runCommand", "git", []string{"rev-parse", "--is-inside-work-tree"}).Return("true", nil)
 	g := &git{
 		env: env,
 	}
@@ -30,7 +30,7 @@ func TestGetGitOutputForCommand(t *testing.T) {
 	commandArgs := []string{"symbolic-ref", "--short", "HEAD"}
 	want := "je suis le output"
 	env := new(MockedEnvironment)
-	env.On("runCommand", "git", append(args, commandArgs...)).Return(want)
+	env.On("runCommand", "git", append(args, commandArgs...)).Return(want, nil)
 	g := &git{
 		env: env,
 	}
@@ -70,12 +70,12 @@ func setupHEADContextEnv(context *detachedContext) *git {
 	env.On("getFileContent", "/.git/MERGE_HEAD").Return(context.mergeHEAD)
 	env.On("hasFiles", "/.git/CHERRY_PICK_HEAD").Return(context.cherryPick)
 	env.On("hasFiles", "/.git/MERGE_HEAD").Return(context.merge)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "rev-parse", "--short", "HEAD"}).Return(context.currentCommit)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "describe", "--tags", "--exact-match"}).Return(context.tagName)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.origin}).Return(context.origin)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.onto}).Return(context.onto)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.cherryPickSHA}).Return(context.cherryPickSHA)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.mergeHEAD}).Return(context.mergeHEAD)
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "rev-parse", "--short", "HEAD"}).Return(context.currentCommit, nil)
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "describe", "--tags", "--exact-match"}).Return(context.tagName, nil)
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.origin}).Return(context.origin, nil)
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.onto}).Return(context.onto, nil)
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.cherryPickSHA}).Return(context.cherryPickSHA, nil)
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "name-rev", "--name-only", "--exclude=tags/*", context.mergeHEAD}).Return(context.mergeHEAD, nil)
 	g := &git{
 		env: env,
 		repo: &gitRepo{
@@ -200,7 +200,7 @@ func TestGetGitHEADContextMergeTag(t *testing.T) {
 func TestGetStashContextZeroEntries(t *testing.T) {
 	want := ""
 	env := new(MockedEnvironment)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "rev-list", "--walk-reflogs", "--count", "refs/stash"}).Return("")
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "rev-list", "--walk-reflogs", "--count", "refs/stash"}).Return("", nil)
 	g := &git{
 		env: env,
 	}
@@ -211,7 +211,7 @@ func TestGetStashContextZeroEntries(t *testing.T) {
 func TestGetStashContextMultipleEntries(t *testing.T) {
 	want := "2"
 	env := new(MockedEnvironment)
-	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "rev-list", "--walk-reflogs", "--count", "refs/stash"}).Return("2")
+	env.On("runCommand", "git", []string{"-c", "core.quotepath=false", "-c", "color.status=false", "rev-list", "--walk-reflogs", "--count", "refs/stash"}).Return("2", nil)
 	g := &git{
 		env: env,
 	}

segment_kubectl.go

@@ -19,6 +19,6 @@ func (k *kubectl) enabled() bool {
 	if !k.env.hasCommand("kubectl") {
 		return false
 	}
-	k.contextName = k.env.runCommand("kubectl", "config", "current-context")
+	k.contextName, _ = k.env.runCommand("kubectl", "config", "current-context")
 	return true
 }

segment_kubectl_test.go

@@ -14,7 +14,7 @@ type kubectlArgs struct {
 func bootStrapKubectlTest(args *kubectlArgs) *kubectl {
 	env := new(MockedEnvironment)
 	env.On("hasCommand", "kubectl").Return(args.enabled)
-	env.On("runCommand", "kubectl", []string{"config", "current-context"}).Return(args.contextName)
+	env.On("runCommand", "kubectl", []string{"config", "current-context"}).Return(args.contextName, nil)
 	k := &kubectl{
 		env:   env,
 		props: &properties{},

segment_node.go

@@ -6,11 +6,6 @@ type node struct {
 	nodeVersion string
 }
 
-const (
-	//DisplayVersion show the version number or not
-	DisplayVersion Property = "display_version"
-)
-
 func (n *node) string() string {
 	if n.props.getBool(DisplayVersion, true) {
 		return n.nodeVersion
@@ -30,6 +25,6 @@ func (n *node) enabled() bool {
 	if !n.env.hasCommand("node") {
 		return false
 	}
-	n.nodeVersion = n.env.runCommand("node", "--version")
+	n.nodeVersion, _ = n.env.runCommand("node", "--version")
 	return true
 }

segment_node_test.go

@@ -17,7 +17,7 @@ type nodeArgs struct {
 func bootStrapNodeTest(args *nodeArgs) *node {
 	env := new(MockedEnvironment)
 	env.On("hasCommand", "node").Return(args.enabled)
-	env.On("runCommand", "node", []string{"--version"}).Return(args.nodeVersion)
+	env.On("runCommand", "node", []string{"--version"}).Return(args.nodeVersion, nil)
 	env.On("hasFiles", "*.js").Return(args.hasJS)
 	env.On("hasFiles", "*.ts").Return(args.hasTS)
 	props := &properties{

segment_path_test.go

@@ -68,9 +68,9 @@ func (env *MockedEnvironment) hasCommand(command string) bool {
 	return args.Bool(0)
 }
 
-func (env *MockedEnvironment) runCommand(command string, args ...string) string {
+func (env *MockedEnvironment) runCommand(command string, args ...string) (string, error) {
 	arguments := env.Called(command, args)
-	return arguments.String(0)
+	return arguments.String(0), arguments.Error(1)
 }
 
 func (env *MockedEnvironment) runShellCommand(shell string, command string) string {

segment_python.go

@@ -38,7 +38,7 @@ func (p *python) enabled() bool {
 		"python",
 	}
 	for index, python := range pythonVersions {
-		version := p.env.runCommand(python, "--version")
+		version, _ := p.env.runCommand(python, "--version")
 		if version != "" {
 			rawVersion := strings.TrimLeft(version, "Python")
 			p.pythonVersion = strings.Trim(rawVersion, " ")

segment_python_test.go

@@ -15,8 +15,8 @@ type pythonArgs struct {
 	pathSeparator    string
 	pythonVersion    string
 	python3Version   string
-	hasPyFiles         bool
-	hasNotebookFiles   bool
+	hasPyFiles       bool
+	hasNotebookFiles bool
 }
 
 func newPythonArgs() *pythonArgs {
@@ -37,8 +37,8 @@ func bootStrapPythonTest(args *pythonArgs) *python {
 	env := new(MockedEnvironment)
 	env.On("hasFiles", "*.py").Return(args.hasPyFiles)
 	env.On("hasFiles", "*.ipynb").Return(args.hasNotebookFiles)
-	env.On("runCommand", "python", []string{"--version"}).Return(args.pythonVersion)
-	env.On("runCommand", "python3", []string{"--version"}).Return(args.python3Version)
+	env.On("runCommand", "python", []string{"--version"}).Return(args.pythonVersion, nil)
+	env.On("runCommand", "python3", []string{"--version"}).Return(args.python3Version, nil)
 	env.On("getenv", "VIRTUAL_ENV").Return(args.virtualEnvName)
 	env.On("getenv", "CONDA_ENV_PATH").Return(args.condaEnvName)
 	env.On("getenv", "CONDA_DEFAULT_ENV").Return(args.condaDefaultName)

segment_spotify.go

@@ -61,5 +61,6 @@ func (s *spotify) init(props *properties, env environmentInfo) {
 }
 
 func (s *spotify) runAppleScriptCommand(command string) string {
-	return s.env.runCommand("osascript", "-e", command)
+	val, _ := s.env.runCommand("osascript", "-e", command)
+	return val
 }