Brew cask should only run in macos (fix #467) (#468)

src/steps/os/macos.rs

@@ -1,5 +1,5 @@
 use crate::execution_context::ExecutionContext;
-use crate::executor::RunType;
+use crate::executor::{CommandExt, RunType};
 use crate::terminal::{print_separator, prompt_yesno};
 use crate::{
     error::{SkipStep, TopgradeError},
@@ -19,6 +19,40 @@ pub fn run_msupdate(ctx: &ExecutionContext) -> Result<()> {
     ctx.run_type().execute(msupdate).arg("--install").check_run()
 }
 
+pub fn run_brew_cask(ctx: &ExecutionContext) -> Result<()> {
+    let brew = require("brew")?;
+    print_separator("Brew Cask");
+
+    let config = ctx.config();
+    let run_type = ctx.run_type();
+
+    let cask_upgrade_exists = Command::new(&brew)
+        .args(&["--repository", "buo/cask-upgrade"])
+        .check_output()
+        .map(|p| Path::new(p.trim()).exists())?;
+
+    let cask_args = if cask_upgrade_exists {
+        let mut args = vec!["cu", "-y"];
+        if config.brew_cask_greedy() {
+            args.push("-a");
+        }
+        args
+    } else {
+        let mut args = vec!["cask", "upgrade"];
+        if config.brew_cask_greedy() {
+            args.push("--greedy");
+        }
+        args
+    };
+    run_type.execute(&brew).args(&cask_args).check_run()?;
+
+    if ctx.config().cleanup() {
+        run_type.execute(&brew).arg("cleanup").check_run()?;
+    }
+
+    Ok(())
+}
+
 pub fn run_macports(ctx: &ExecutionContext) -> Result<()> {
     require("port")?;
     let sudo = ctx.sudo().as_ref().unwrap();