feat(check): check for convert on launch #6

 - check if convert can run
 - suggest installtion instruction on error case

src/any/mod.rs

@@ -16,3 +16,6 @@ pub fn screenshot_and_save(
 ) -> anyhow::Result<()> {
     unimplemented!("there is only an impl for MacOS")
 }
+
+// references for winRT
+// https://github.com/robmikh/wgc-rust-demo/blob/master/src/main.rs

src/main.rs

@@ -15,7 +15,7 @@ use anyhow::Context;
 use anyhow::Result;
 use std::borrow::Borrow;
 use std::ffi::OsStr;
-use std::process::{Command, ExitStatus};
+use std::process::{Command, ExitStatus, Output};
 use std::sync::mpsc::Receiver;
 use std::sync::{mpsc, Arc, Mutex};
 use std::time::{Duration, Instant};
@@ -48,6 +48,8 @@ fn main() -> Result<()> {
         }
     };
 
+    check_for_imagemagick()?;
+
     // the nice thing is the cleanup on drop
     let tempdir = Arc::new(Mutex::new(
         TempDir::new().context("Cannot create tempdir.")?,
@@ -149,6 +151,16 @@ fn current_win_id() -> Result<u32> {
     }
 }
 
+///
+/// checks for imagemagick
+/// and suggests the installation command if there are issues
+fn check_for_imagemagick() -> Result<Output> {
+    Command::new("convert")
+        .arg("--version")
+        .output()
+        .context("There is an issue with 'convert', make sure you have it installed: `brew install imagemagick`")
+}
+
 ///
 /// generating the final gif with help of convert
 fn generate_gif_with_convert(time_codes: &[u128], tempdir: &TempDir) -> Result<()> {