Merge pull request #289 from o2sh/remove-panic-from-info-fmt

return Err when image but no image backend

Author: o2sh

Diff for: src/onefetch/cli.rs

@@ -138,6 +138,7 @@ impl Cli {
                 .long("image-backend")
                 .value_name("BACKEND")
                 .takes_value(true)
+                .requires("image")
                 .max_values(1)
                 .possible_values(&possible_backends)
                 .help("Which image BACKEND to use."),
@@ -218,6 +219,7 @@ impl Cli {
 
         let image_backend = if image.is_some() {
             if let Some(backend_name) = matches.value_of("image-backend") {
+                image_backends::check_if_supported(backend_name)?;
                 image_backends::get_image_backend(backend_name)
             } else {
                 image_backends::get_best_backend()
@@ -226,6 +228,10 @@ impl Cli {
             None
         };
 
+        if image.is_some() && image_backend.is_none() {
+            return Err("Could not detect a supported image backend".into());
+        }
+
         let image_colors = if let Some(value) = matches.value_of("color-resolution") {
             usize::from_str(value).unwrap()
         } else {

Diff for: src/onefetch/cli_utils.rs

@@ -24,15 +24,11 @@ impl<W: Write> Printer<W> {
         if self.info.config.art_off {
             buf.push_str(&info_str);
         } else if let Some(custom_image) = &self.info.config.image {
-            if let Some(image_backend) = &self.info.config.image_backend {
-                buf.push_str(&image_backend.add_image(
-                    info_lines.map(|s| format!("{}{}", center_pad, s)).collect(),
-                    custom_image,
-                    self.info.config.image_colors,
-                ));
-            } else {
-                panic!("No image backend found")
-            }
+            buf.push_str(&self.info.config.image_backend.as_ref().unwrap().add_image(
+                info_lines.map(|s| format!("{}{}", center_pad, s)).collect(),
+                custom_image,
+                self.info.config.image_colors,
+            ));
         } else {
             let mut logo_lines = if let Some(custom_ascii) = &self.info.config.ascii_input {
                 AsciiArt::new(custom_ascii, &colors, !self.info.config.no_bold)

Diff for: src/onefetch/image_backends/mod.rs

@@ -1,3 +1,4 @@
+use crate::onefetch::error::*;
 use image::DynamicImage;
 
 #[cfg(not(windows))]
@@ -20,6 +21,28 @@ pub fn get_best_backend() -> Option<Box<dyn ImageBackend>> {
     }
 }
 
+pub fn check_if_supported(backend_name: &str) -> Result<()> {
+    #[cfg(windows)]
+    return Err(format!("{} image backend is not supported", backend_name).into());
+
+    #[cfg(not(windows))]
+    match backend_name {
+        "kitty" => {
+            if !kitty::KittyBackend::supported() {
+                return Err("Kitty image backend is not supported".into());
+            }
+        }
+        "sixel" => {
+            if !sixel::SixelBackend::supported() {
+                return Err("Sixel image backend is not supported".into());
+            }
+        }
+        _ => unreachable!(),
+    };
+
+    Ok(())
+}
+
 pub fn get_image_backend(backend_name: &str) -> Option<Box<dyn ImageBackend>> {
     #[cfg(not(windows))]
     let backend = Some(match backend_name {