Define a separate files.rs for reading and content checking

src/files.rs

@@ -0,0 +1,34 @@
+use std::fs;
+
+pub fn read_or_die(path: &str) -> Vec<u8> {
+    match fs::read(path) {
+        Ok(src) => src,
+        Err(e) => {
+            match e.kind() {
+                std::io::ErrorKind::NotFound => {
+                    eprintln!("No such file: {}", path);
+                }
+                std::io::ErrorKind::PermissionDenied => {
+                    eprintln!("Permission denied when reading file: {}", path);
+                }
+                _ => {
+                    eprintln!("Could not read file: {} (error {:?})", path, e.kind());
+                }
+            };
+            std::process::exit(1);
+        }
+    }
+}
+
+/// Do these bytes look like a binary (non-textual) format?
+pub fn is_probably_binary(bytes: &[u8]) -> bool {
+    // If more than 20 of the first 1,000 characters are not valid
+    // UTF-8, we assume it's binary.
+    let num_replaced = String::from_utf8_lossy(bytes)
+        .to_string()
+        .chars()
+        .take(1000)
+        .filter(|c| *c == std::char::REPLACEMENT_CHARACTER)
+        .count();
+    num_replaced > 20
+}

src/main.rs

@@ -1,4 +1,5 @@
 mod dijkstra;
+mod files;
 mod inline;
 mod intervals;
 mod line_parser;
@@ -11,49 +12,17 @@ mod syntax;
 mod tree_sitter_parser;
 use atty::Stream;
 use clap::{App, AppSettings, Arg};
+use std::env;
 use std::ffi::OsStr;
 use std::path::Path;
-use std::{env, fs};
 use typed_arena::Arena;
 
 use crate::dijkstra::mark_syntax;
+use crate::files::{is_probably_binary, read_or_die};
 use crate::lines::{join_overlapping, visible_groups, MaxLine};
 use crate::syntax::{change_positions, init_info, matching_lines};
 use crate::tree_sitter_parser as tsp;
 
-fn read_or_die(path: &str) -> Vec<u8> {
-    match fs::read(path) {
-        Ok(src) => src,
-        Err(e) => {
-            match e.kind() {
-                std::io::ErrorKind::NotFound => {
-                    eprintln!("No such file: {}", path);
-                }
-                std::io::ErrorKind::PermissionDenied => {
-                    eprintln!("Permission denied when reading file: {}", path);
-                }
-                _ => {
-                    eprintln!("Could not read file: {} (error {:?})", path, e.kind());
-                }
-            };
-            std::process::exit(1);
-        }
-    }
-}
-
-/// Do these bytes look like a binary (non-textual) format?
-fn is_probably_binary(bytes: &[u8]) -> bool {
-    // If more than 20 of the first 1,000 characters are not valid
-    // UTF-8, we assume it's binary.
-    let num_replaced = String::from_utf8_lossy(bytes)
-        .to_string()
-        .chars()
-        .take(1000)
-        .filter(|c| *c == std::char::REPLACEMENT_CHARACTER)
-        .count();
-    num_replaced > 20
-}
-
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 
 fn configure_color() {