cmd: Create config setting to control sort order

Closes #12

README.md

@@ -148,25 +148,29 @@ Use "hvm [command] --help" for more information about a command.
 
 ## Configuration
 
-### Number of releases to display
+To locate the configuration file, run the `hvm config` command. This will print the path to the configuration file to the console. Keys in the configuration file are case-insensitive.
 
-By default, the `hvm use` and `hvm install` commands display the 30 most recent releases. To change the number of releases displayed, you can do one of the following:
+To set configuration values with an environment variable, create an environment variable prefixed with `HVM_`. For example, to set the `sortAscending` configuration value to false:
 
-- Set the `numtagstodisplay` option in the hvm configuration file. You can find the path to the configuration file by running the `hvm config` command.
-- Set the `HVM_NUMTAGSTODISPLAY` environment variable.
+```text
+export HVM_SORTASCENDING=false
+```
 
-To display all releases since v0.54.0, set the value to `-1`. Releases before v0.54.0 were not semantically versioned.
+An environment variable takes precedence over the values set in the configuration file. This means that if you set a configuration value with both an environment variable and in the configuration file, the value in the environment variable will be used.
 
-### GitHub personal access token
+**gitHubToken** (string)
 
 GitHub limits the number of requests that can be made to its API per hour to 60 for unauthenticated clients. If you exceed this limit, hvm will display a message indicating when the limit will be reset. This is typically within minutes.
 
-If you regularly exceed this limit, you can create a GitHub personal access token with read-only public repository access. Then, you can do either of the following:
+If you regularly exceed this limit, you can create a GitHub personal access token with read-only public repository access. With a personal access token, GitHub limits API requests to 5,000 per hour.
+
+**numTagsToDisplay** (int, default `30`)
+
+By default, the `hvm use` and `hvm install` commands display the 30 most recent releases. To display all releases since v0.54.0, set the value to `-1`. Releases before v0.54.0 were not semantically versioned.
 
-- Set the `githubtoken` option in the hvm configuration file. You can find the path to the configuration file by running the hvm config command.
-- Set the `HVM_GITHUBTOKEN` environment variable.
+**sortAscending** (bool, default `true`)
 
-With a personal access token, GitHub limits API requests to 5,000 per hour.
+By default, the `hvm use` and `hvm install` commands display the list of recent releases in ascending order. To display the list in descending order, set this value to `false`.
 
 [go]: https://go.dev/doc/install
 [hugo]: https://github.com/gohugoio/hugo/#readme

cmd/hvm/cmd.go

@@ -45,8 +45,9 @@ type application struct {
 // A configuration contains the current configuration parameters from environment
 // variables, the configuration file, or default values, in that order.
 type configuration struct {
-	GithubToken      string // a GitHub personal access token
-	NumTagsToDisplay int    // number of tags to display when using the "use" and "install" commands
+	GithubToken      string `toml:"githubToken"`      // a GitHub personal access token
+	NumTagsToDisplay int    `toml:"numTagsToDisplay"` // number of tags to display when using the "use" and "install" commands
+	SortAscending    bool   `toml:"sortAscending"`    // displays tags list in ascending order
 }
 
 var App application = application{
@@ -98,8 +99,9 @@ func init() {
 // initConfig reads in config file and ENV variables if set.
 func initConfig() {
 	// Set default values.
-	viper.SetDefault("numTagsToDisplay", 30)
 	viper.SetDefault("githubToken", "")
+	viper.SetDefault("numTagsToDisplay", 30)
+	viper.SetDefault("sortAscending", true)
 
 	// Create config directory.
 	userConfigDir, err := os.UserConfigDir()

cmd/hvm/testscripts/config.txt

@@ -9,5 +9,7 @@
 
 # Test
 exec hvm config
-stdout 'NumTagsToDisplay = 30\n'
+stdout 'githubToken = ''''\n'
+stdout 'numTagsToDisplay = 30\n'
+stdout 'sortAscending = true\n'
 stdout 'Configuration file: '

cmd/hvm/testscripts/config_with_env_vars.txt

@@ -7,11 +7,13 @@
 [windows] env LocalAppData=cache
 [windows] env AppData=config
 
-env HVM_NUMTAGSTODISPLAY=42
 env HVM_GITHUBTOKEN=my-token
+env HVM_NUMTAGSTODISPLAY=42
+env HVM_SORTASCENDING=true
 
 # Test
 exec hvm config
-stdout 'GithubToken = ''my-token''\n'
-stdout 'NumTagsToDisplay = 42\n'
+stdout 'githubToken = ''my-token''\n'
+stdout 'numTagsToDisplay = 42\n'
+stdout 'sortAscending = true\n'
 stdout 'Configuration file: '

cmd/hvm/testscripts/config_with_file.txt

@@ -9,16 +9,19 @@
 
 # Test
 exec hvm config
-stdout 'GithubToken = ''my-token''\n'
-stdout 'NumTagsToDisplay = 42\n'
+stdout 'githubToken = ''my-token''\n'
+stdout 'numTagsToDisplay = 42\n'
+stdout 'sortAscending = false'
 stdout 'Configuration file: '
 
 # Files for darwin
 -- home/Library/Application Support/hvm/config.toml --
 githubtoken = "my-token"
 numtagstodisplay = 42
+sortascending = false
 
 # Files for linux and windows
 -- config/hvm/config.toml --
 githubtoken = "my-token"
 numtagstodisplay = 42
+sortascending = false

cmd/hvm/use.go

@@ -200,7 +200,9 @@ func (r *repository) fetchTags() error {
 		}
 	}
 
-	semver.Sort(tagNames)
+	if Config.SortAscending {
+		semver.Sort(tagNames)
+	}
 
 	n := Config.NumTagsToDisplay
 	if n < 0 {