Always show a warning when theme is unknown

src/app.rs

@@ -1,4 +1,3 @@
-use assets::HighlightingAssets;
 use atty::{self, Stream};
 use clap::{App as ClapApp, AppSettings, Arg, ArgGroup, ArgMatches, SubCommand};
 use console::Term;
@@ -287,15 +286,8 @@ impl App {
                 .matches
                 .value_of("theme")
                 .map(String::from)
-                .or_else(|| {
-                    env::var("BAT_THEME").ok().and_then(|theme_name_env| {
-                        if HighlightingAssets::new().theme_exists(&theme_name_env) {
-                            Some(theme_name_env)
-                        } else {
-                            None
-                        }
-                    })
-                }),
+                .or_else(|| env::var("BAT_THEME").ok())
+                .unwrap_or(String::from("Default")),
             line_range: transpose(self.matches.value_of("line-range").map(LineRange::from))?,
         })
     }
@@ -349,7 +341,7 @@ pub struct Config<'a> {
     pub paging_mode: PagingMode,
     pub term_width: usize,
     pub files: Vec<Option<&'a str>>,
-    pub theme: Option<String>,
+    pub theme: String,
     pub line_range: Option<LineRange>,
 }
 

src/assets.rs

@@ -2,7 +2,6 @@ use directories::ProjectDirs;
 use errors::*;
 use std::borrow::Cow;
 use std::fs::{self, File};
-use std::io;
 use std::path::{Path, PathBuf};
 use syntect::dumps::{dump_to_file, from_binary, from_reader};
 use syntect::highlighting::{Theme, ThemeSet};
@@ -123,17 +122,19 @@ impl HighlightingAssets {
         Ok(())
     }
 
-    pub fn get_theme(&self, theme: &str) -> Result<&Theme> {
-        Ok(self.theme_set.themes.get(theme).ok_or_else(|| {
-            io::Error::new(
-                io::ErrorKind::Other,
-                format!("Could not find '{}' theme", theme),
-            )
-        })?)
-    }
-
-    pub fn theme_exists(&self, theme: &str) -> bool {
-        self.theme_set.themes.contains_key(theme)
+    pub fn get_theme(&self, theme: &str) -> &Theme {
+        match self.theme_set.themes.get(theme) {
+            Some(theme) => theme,
+            None => {
+                use ansi_term::Colour::Yellow;
+                eprintln!(
+                    "{}: Unknown theme '{}', using default.",
+                    Yellow.paint("[bat warning]"),
+                    theme
+                );
+                &self.theme_set.themes["Default"]
+            }
+        }
     }
 
     pub fn get_syntax(&self, language: Option<&str>, filename: Option<&str>) -> &SyntaxDefinition {

src/features.rs

@@ -57,10 +57,7 @@ pub fn list_languages(assets: &HighlightingAssets, term_width: usize) {
 }
 
 pub fn print_files(assets: &HighlightingAssets, config: &Config) -> Result<bool> {
-    let theme = assets.get_theme(match config.theme {
-        Some(ref theme_name) => theme_name,
-        None => "Default",
-    })?;
+    let theme = assets.get_theme(&config.theme);
 
     let mut output_type = OutputType::from_mode(config.paging_mode);
     let handle = output_type.handle()?;