Move paging support behind a feature

Cargo.toml

@@ -26,9 +26,11 @@ application = [
     "git",
     "lazy_static",
     "liquid",
+    "paging",
     "wild",
 ]
 git = ["git2"] # Support indicating git modifications
+paging = ["shell-words"] # Support applying a pager on the output
 
 [dependencies]
 atty = { version = "0.2.14", optional = true }
@@ -40,7 +42,7 @@ lazy_static = { version = "1.4", optional = true }
 wild = { version = "2.0", optional = true }
 content_inspector = "0.2.4"
 encoding = "0.2"
-shell-words = "0.1.0"
+shell-words = { version = "0.1.0", optional = true }
 unicode-width = "0.1.7"
 globset = "0.4"
 

ci/script.bash

@@ -16,3 +16,4 @@ fi
 # Check bat-as-a-library, which has a smaller set of dependencies
 cargo check --target "$TARGET" --verbose --lib --no-default-features
 cargo check --target "$TARGET" --verbose --lib --no-default-features --features git
+cargo check --target "$TARGET" --verbose --lib --no-default-features --features paging

src/config.rs

@@ -6,7 +6,9 @@ pub use crate::wrap::OutputWrap;
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum PagingMode {
+    #[cfg(feature = "paging")]
     Always,
+    #[cfg(feature = "paging")]
     QuitIfOneScreen,
     Never,
 }

src/less.rs

@@ -1,3 +1,5 @@
+#![cfg(feature = "paging")]
+
 use std::process::Command;
 
 pub fn retrieve_less_version() -> Option<usize> {

src/output.rs

@@ -1,31 +1,39 @@
-use std::env;
-use std::ffi::OsString;
 use std::io::{self, Write};
-use std::path::PathBuf;
+#[cfg(feature = "paging")]
-use std::process::{Child, Command, Stdio};
+use std::process::Child;
 
 use crate::config::PagingMode;
 use crate::errors::*;
+#[cfg(feature = "paging")]
 use crate::less::retrieve_less_version;
 
 #[derive(Debug)]
 pub enum OutputType {
+    #[cfg(feature = "paging")]
     Pager(Child),
     Stdout(io::Stdout),
 }
 
 impl OutputType {
     pub fn from_mode(mode: PagingMode, pager: Option<&str>) -> Result<Self> {
-        use self::PagingMode::*;
+        let _ = pager;
         Ok(match mode {
-            Always => OutputType::try_pager(false, pager)?,
+            #[cfg(feature = "paging")]
-            QuitIfOneScreen => OutputType::try_pager(true, pager)?,
+            PagingMode::Always => OutputType::try_pager(false, pager)?,
+            #[cfg(feature = "paging")]
+            PagingMode::QuitIfOneScreen => OutputType::try_pager(true, pager)?,
             _ => OutputType::stdout(),
         })
     }
 
     /// Try to launch the pager. Fall back to stdout in case of errors.
+    #[cfg(feature = "paging")]
     fn try_pager(quit_if_one_screen: bool, pager_from_config: Option<&str>) -> Result<Self> {
+        use std::env;
+        use std::ffi::OsString;
+        use std::path::PathBuf;
+        use std::process::{Command, Stdio};
+
         let mut replace_arguments_to_less = false;
 
         let pager_from_env = match (env::var("BAT_PAGER"), env::var("PAGER")) {
@@ -114,6 +122,7 @@ impl OutputType {
 
     pub fn handle(&mut self) -> Result<&mut dyn Write> {
         Ok(match *self {
+            #[cfg(feature = "paging")]
             OutputType::Pager(ref mut command) => command
                 .stdin
                 .as_mut()
@@ -123,6 +132,7 @@ impl OutputType {
     }
 }
 
+#[cfg(feature = "paging")]
 impl Drop for OutputType {
     fn drop(&mut self) {
         if let OutputType::Pager(ref mut command) = *self {