Add 'packages upgrade' command.

crates/aiken/src/cmd/packages/add.rs

@@ -17,10 +17,13 @@ pub struct Args {
     ///
     /// Note that by default, this assumes the package is located
     /// on Github.
-    package: String,
+    pub package: String,
     /// The package version, as a git commit hash, a tag or a branch name.
     #[clap(long)]
-    version: String,
+    pub version: String,
+
+    #[clap(hide = true)]
+    pub overwrite: bool,
 }
 
 pub fn exec(args: Args) -> miette::Result<()> {
@@ -42,20 +45,24 @@ pub fn exec(args: Args) -> miette::Result<()> {
 
     println!(
         "{} {}",
-        pretty::pad_left("Adding".to_string(), 13, " ")
+        pretty::pad_left("Package".to_string(), 13, " ")
             .bold()
             .purple(),
         dependency.name.bright_blue(),
     );
 
-    match config.insert(&dependency, false) {
+    match config.insert(&dependency, args.overwrite) {
         Some(config) => {
             config.save(&root).into_diagnostic()?;
             println!(
-                "{} version = {}",
-                pretty::pad_left("Added".to_string(), 13, " ")
-                    .bold()
-                    .purple(),
+                "{} version → {}",
+                pretty::pad_left(
+                    if args.overwrite { "Changed" } else { "Added" }.to_string(),
+                    13,
+                    " "
+                )
+                .bold()
+                .purple(),
                 dependency.version.yellow()
             );
             Ok(())

crates/aiken/src/cmd/packages/mod.rs

@@ -1,5 +1,6 @@
 pub mod add;
 pub mod clear_cache;
+pub mod upgrade;
 
 use clap::Subcommand;
 
@@ -10,6 +11,9 @@ pub enum Cmd {
     /// Add a new package dependency
     Add(add::Args),
 
+    /// Change the version of an installed dependency
+    Upgrade(upgrade::Args),
+
     /// Clear the system-wide dependencies cache
     ClearCache,
 }
@@ -18,5 +22,6 @@ pub fn exec(cmd: Cmd) -> miette::Result<()> {
     match cmd {
         Cmd::Add(args) => add::exec(args),
         Cmd::ClearCache => clear_cache::exec(),
+        Cmd::Upgrade(args) => upgrade::exec(args),
     }
 }

crates/aiken/src/cmd/packages/upgrade.rs

@@ -0,0 +1,24 @@
+use super::add;
+
+#[derive(clap::Args)]
+/// Change the version of an installed dependency
+pub struct Args {
+    /// Package name, in the form of {owner}/{repository}.
+    ///
+    /// For example → 'add aiken-lang/stdlib'
+    ///
+    /// Note that by default, this assumes the package is located
+    /// on Github.
+    package: String,
+    /// The package version, as a git commit hash, a tag or a branch name.
+    #[clap(long)]
+    version: String,
+}
+
+pub fn exec(args: Args) -> miette::Result<()> {
+    add::exec(add::Args {
+        package: args.package,
+        version: args.version,
+        overwrite: true,
+    })
+}