Merge pull request #3438 from lmmx/pipe-style

feat: make output pipeable with `-n`, non-auto styles

CHANGELOG.md

@@ -24,6 +24,7 @@
 - `--style=changes` no longer prints a two-space indent when the file is unmodified, see issue #2710 and PR #3406 (@jyn514)
 - Add missing shell completions, see #3411 (@keith-hall)
 - Execute help/version/diagnostic commands even with invalid config/arguments present, see #3414 (@keith-hall)
+- Fixed line numbers (`-n`) and style components not printing when piping output, see issue #2935 and PR #3438 (@lmmx)
 
 ## Other
 

assets/manual/bat.1.in

@@ -14,7 +14,8 @@ It also communicates with git(1) to show modifications with respect to the git i
 
 Whenever the output of {{PROJECT_EXECUTABLE}} goes to a non-interactive terminal, i.e. when the
 output is piped into another process or into a file, {{PROJECT_EXECUTABLE}} will act as a drop-in
-replacement for cat(1) and fall back to printing the plain file contents.
+replacement for cat(1) and fall back to printing the plain file contents,
+unless an explicit style is requested.
 
 .SH "OPTIONS"
 General remarks: Command-line options like '-l'/'--language' that take values can be specified as
@@ -131,7 +132,8 @@ always, *never*.
 \fB\-\-decorations\fR <when>
 .IP
 Specify when to use the decorations that have been specified via '\-\-style'. The
-automatic mode only enables decorations if an interactive terminal is detected. Possible
+automatic mode only enables decorations if an interactive terminal is detected. The
+always mode will show decorations even when piping output. Possible
 values: *auto*, never, always.
 .HP
 \fB\-f\fR, \fB\-\-force\-colorization\fR

doc/long-help.txt

@@ -87,8 +87,8 @@ Options:
 
       --decorations <when>
           Specify when to use the decorations that have been specified via '--style'. The automatic
-          mode only enables decorations if an interactive terminal is detected. Possible values:
-          *auto*, never, always.
+          mode only enables decorations if an interactive terminal is detected. The always mode will
+          show decorations even when piping output. Possible values: *auto*, never, always.
 
   -f, --force-colorization
           Alias for '--decorations=always --color=always'. This is useful if the output of bat is

src/bin/bat/app.rs

@@ -276,7 +276,9 @@ impl App {
                     .get_one::<String>("decorations")
                     .map(|s| s.as_str())
                     == Some("always")
-                || self.matches.get_flag("force-colorization")),
+                || self.matches.get_flag("force-colorization")
+                || self.matches.get_flag("number")
+                || self.matches.contains_id("style") && !style_components.plain()),
             tab_width: self
                 .matches
                 .get_one::<String>("tabs")

src/bin/bat/clap_app.rs

@@ -300,8 +300,9 @@ pub fn build_app(interactive_output: bool) -> Command {
                 .long_help(
                     "Specify when to use the decorations that have been specified \
                     via '--style'. The automatic mode only enables decorations if \
-                     an interactive terminal is detected. Possible values: *auto*, never, always.",
-                ),
+                    an interactive terminal is detected. The always mode will show \
+                    decorations even when piping output. Possible values: *auto*, never, always.",
+                )
         )
         .arg(
             Arg::new("force-colorization")

tests/integration_tests.rs

@@ -378,6 +378,83 @@ fn line_range_context_very_large() {
         );
 }
 
+#[test]
+fn piped_output_with_implicit_auto_style() {
+    bat()
+        .write_stdin("hello\nworld\n")
+        .assert()
+        .success()
+        .stdout("hello\nworld\n");
+}
+
+#[test]
+fn piped_output_with_line_number_flag() {
+    bat()
+        .arg("--number")
+        .write_stdin("hello\nworld\n")
+        .assert()
+        .success()
+        .stdout("   1 hello\n   2 world\n");
+}
+
+#[test]
+fn piped_output_with_line_numbers_style_flag() {
+    bat()
+        .arg("--style=numbers")
+        .write_stdin("hello\nworld\n")
+        .assert()
+        .success()
+        .stdout("   1 hello\n   2 world\n");
+}
+
+#[test]
+#[cfg(not(target_os = "windows"))]
+fn piped_output_with_line_numbers_with_header_grid_style_flag() {
+    bat()
+        .arg("--style=header,grid,numbers")
+        .write_stdin("hello\nworld\n")
+        .assert()
+        .success()
+        .stdout(
+            "─────┬──────────────────────────────────────────────────────────────────────────
+     │ STDIN
+─────┼──────────────────────────────────────────────────────────────────────────
+   1 │ hello
+   2 │ world
+─────┴──────────────────────────────────────────────────────────────────────────
+",
+        );
+}
+
+#[test]
+fn piped_output_with_auto_style() {
+    bat()
+        .arg("--style=auto")
+        .write_stdin("hello\nworld\n")
+        .assert()
+        .success()
+        .stdout("hello\nworld\n"); // Should be plain when piped
+}
+
+#[test]
+#[cfg(not(target_os = "windows"))]
+fn piped_output_with_default_style_flag() {
+    bat()
+        .arg("--style=default")
+        .write_stdin("hello\nworld\n")
+        .assert()
+        .success()
+        .stdout(
+            "─────┬──────────────────────────────────────────────────────────────────────────
+     │ STDIN
+─────┼──────────────────────────────────────────────────────────────────────────
+   1 │ hello
+   2 │ world
+─────┴──────────────────────────────────────────────────────────────────────────
+",
+        );
+}
+
 #[test]
 fn squeeze_blank() {
     bat()