Merge pull request #302 from eth-p/feature-tabs

Tab expansion support.

closes #166 
closes #184

src/app.rs

@@ -16,7 +16,7 @@ use errors::*;
 use line_range::LineRange;
 use style::{OutputComponent, OutputComponents, OutputWrap};
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub enum PagingMode {
     Always,
     QuitIfOneScreen,
@@ -41,6 +41,10 @@ pub struct Config<'a> {
     /// The character width of the terminal
     pub term_width: usize,
 
+    /// The width of tab characters.
+    /// Currently, a value of 0 will cause tabs to be passed through without expanding them.
+    pub tab_width: usize,
+
     /// Whether or not to simply loop through all input (`cat` mode)
     pub loop_through: bool,
 
@@ -130,7 +134,7 @@ impl App {
                          to read from standard input.",
                     ).multiple(true)
                     .empty_values(false),
-                    )
+            )
             .arg(
                 Arg::with_name("language")
                     .short("l")
@@ -144,195 +148,209 @@ impl App {
                         language names and file extensions."
                     ).takes_value(true),
             ).arg(
-                Arg::with_name("list-languages")
-                    .long("list-languages")
-                    .conflicts_with("list-themes")
-                    .help("Display all supported languages.")
-                    .long_help("Display a list of supported languages for syntax highlighting."),
-            ).arg(
-                Arg::with_name("theme")
-                    .long("theme")
-                    .overrides_with("theme")
-                    .takes_value(true)
-                    .help("Set the color theme for syntax highlighting.")
-                    .long_help(
-                        "Set the theme for syntax highlighting. Use '--list-themes' to \
+            Arg::with_name("list-languages")
+                .long("list-languages")
+                .conflicts_with("list-themes")
+                .help("Display all supported languages.")
+                .long_help("Display a list of supported languages for syntax highlighting."),
+        ).arg(
+            Arg::with_name("theme")
+                .long("theme")
+                .overrides_with("theme")
+                .takes_value(true)
+                .help("Set the color theme for syntax highlighting.")
+                .long_help(
+                    "Set the theme for syntax highlighting. Use '--list-themes' to \
                          see all available themes. To set a default theme, export the \
                          BAT_THEME environment variable (e.g.: export \
                          BAT_THEME=\"TwoDark\").",
-                    ),
-            ).arg(
-                Arg::with_name("list-themes")
-                    .long("list-themes")
-                    .help("Display all supported highlighting themes.")
-                    .long_help("Display a list of supported themes for syntax highlighting."),
-            ).arg(
-                Arg::with_name("style")
-                    .long("style")
-                    .value_name("style-components")
-                    .use_delimiter(true)
-                    .takes_value(true)
-                    .possible_values(&[
-                        "auto", "full", "plain", "changes", "header", "grid", "numbers",
-                    ]).default_value("auto")
-                    .help("Comma-separated list of style elements to display.")
-                    .long_help(
-                        "Configure which elements (line numbers, file headers, grid \
+                ),
+        ).arg(
+            Arg::with_name("list-themes")
+                .long("list-themes")
+                .help("Display all supported highlighting themes.")
+                .long_help("Display a list of supported themes for syntax highlighting."),
+        ).arg(
+            Arg::with_name("style")
+                .long("style")
+                .value_name("style-components")
+                .use_delimiter(true)
+                .takes_value(true)
+                .possible_values(&[
+                    "auto", "full", "plain", "changes", "header", "grid", "numbers",
+                ]).default_value("auto")
+                .help("Comma-separated list of style elements to display.")
+                .long_help(
+                    "Configure which elements (line numbers, file headers, grid \
                          borders, Git modifications, ..) to display in addition to the \
                          file contents. The argument is a comma-separated list of \
                          components to display (e.g. 'numbers,changes,grid') or a \
                          pre-defined style ('full')",
-                    ),
-            ).arg(
-                Arg::with_name("plain")
-                    .overrides_with("plain")
-                    .short("p")
-                    .long("plain")
-                    .conflicts_with("style")
-                    .conflicts_with("number")
-                    .help("Show plain style (alias for '--style=plain').")
-                    .long_help(
-                        "Only show plain style, no decorations. This is an alias for \
+                ),
+        ).arg(
+            Arg::with_name("plain")
+                .overrides_with("plain")
+                .short("p")
+                .long("plain")
+                .conflicts_with("style")
+                .conflicts_with("number")
+                .help("Show plain style (alias for '--style=plain').")
+                .long_help(
+                    "Only show plain style, no decorations. This is an alias for \
                          '--style=plain'",
-                    ),
-            ).arg(
-                Arg::with_name("number")
-                    .long("number")
-                    .overrides_with("number")
-                    .short("n")
-                    .conflicts_with("style")
-                    .help("Show line numbers (alias for '--style=numbers').")
-                    .long_help(
-                        "Only show line numbers, no other decorations. This is an alias for \
+                ),
+        ).arg(
+            Arg::with_name("number")
+                .long("number")
+                .overrides_with("number")
+                .short("n")
+                .conflicts_with("style")
+                .help("Show line numbers (alias for '--style=numbers').")
+                .long_help(
+                    "Only show line numbers, no other decorations. This is an alias for \
                          '--style=numbers'",
-                    ),
-            ).arg(
-                Arg::with_name("line-range")
-                    .long("line-range")
-                    .overrides_with("line-range")
-                    .takes_value(true)
-                    .value_name("N:M")
-                    .help("Only print the lines from N to M.")
-                    .long_help(
-                        "Only print the specified range of lines for each file. \
+                ),
+        ).arg(
+            Arg::with_name("line-range")
+                .long("line-range")
+                .overrides_with("line-range")
+                .takes_value(true)
+                .value_name("N:M")
+                .help("Only print the lines from N to M.")
+                .long_help(
+                    "Only print the specified range of lines for each file. \
                          For example:\n  \
                          '--line-range 30:40' prints lines 30 to 40\n  \
                          '--line-range :40' prints lines 1 to 40\n  \
                          '--line-range 40:' prints lines 40 to the end of the file",
-                    ),
-            ).arg(
-                Arg::with_name("color")
-                    .long("color")
-                    .overrides_with("color")
-                    .takes_value(true)
-                    .value_name("when")
-                    .possible_values(&["auto", "never", "always"])
-                    .default_value("auto")
-                    .help("When to use colors.")
-                    .long_help("Specify when to use colored output. The automatic mode \
+                ),
+        ).arg(
+            Arg::with_name("color")
+                .long("color")
+                .overrides_with("color")
+                .takes_value(true)
+                .value_name("when")
+                .possible_values(&["auto", "never", "always"])
+                .default_value("auto")
+                .help("When to use colors.")
+                .long_help("Specify when to use colored output. The automatic mode \
                                 only enables colors if an interactive terminal is detected."),
-            ).arg(
-                Arg::with_name("decorations")
-                    .long("decorations")
-                    .overrides_with("decorations")
-                    .takes_value(true)
-                    .value_name("when")
-                    .possible_values(&["auto", "never", "always"])
-                    .default_value("auto")
-                    .help("When to show the decorations specified by '--style'.")
-                    .long_help("Specify when to use the decorations that have been specified \
+        ).arg(
+            Arg::with_name("decorations")
+                .long("decorations")
+                .overrides_with("decorations")
+                .takes_value(true)
+                .value_name("when")
+                .possible_values(&["auto", "never", "always"])
+                .default_value("auto")
+                .help("When to show the decorations specified by '--style'.")
+                .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."),
-            ).arg(
-                Arg::with_name("paging")
-                    .long("paging")
-                    .overrides_with("paging")
-                    .takes_value(true)
-                    .value_name("when")
-                    .possible_values(&["auto", "never", "always"])
-                    .default_value("auto")
-                    .help("Specify when to use the pager.")
-                    .long_help("Specify when to use the pager. To control which pager \
+        ).arg(
+            Arg::with_name("paging")
+                .long("paging")
+                .overrides_with("paging")
+                .takes_value(true)
+                .value_name("when")
+                .possible_values(&["auto", "never", "always"])
+                .default_value("auto")
+                .help("Specify when to use the pager.")
+                .long_help("Specify when to use the pager. To control which pager \
                                 is used, set the PAGER or BAT_PAGER environment \
                                 variables (the latter takes precedence). The default \
                                 pager is 'less'. To disable the pager permanently, set \
                                 BAT_PAGER to an empty string."),
-            ).arg(
-                Arg::with_name("wrap")
-                    .long("wrap")
-                    .overrides_with("wrap")
-                    .takes_value(true)
-                    .value_name("mode")
-                    .possible_values(&["auto", "never", "character"])
-                    .default_value("auto")
-                    .help("Specify the text-wrapping mode.")
-                    .long_help("Specify the text-wrapping mode."),
-            ).arg(
-                Arg::with_name("unbuffered")
-                    .short("u")
-                    .hidden_short_help(true)
-                    .long_help(
-                        "This option exists for POSIX-compliance reasons ('u' is for \
+        ).arg(
+            Arg::with_name("wrap")
+                .long("wrap")
+                .overrides_with("wrap")
+                .takes_value(true)
+                .value_name("mode")
+                .possible_values(&["auto", "never", "character"])
+                .default_value("auto")
+                .help("Specify the text-wrapping mode.")
+                .long_help("Specify the text-wrapping mode."),
+        ).arg(
+            Arg::with_name("unbuffered")
+                .short("u")
+                .hidden_short_help(true)
+                .long_help(
+                    "This option exists for POSIX-compliance reasons ('u' is for \
                          'unbuffered'). The output is always unbuffered - this option \
                          is simply ignored.",
+                ),
+        ).arg(
+            Arg::with_name("tabs")
+                .long("tabs")
+                .takes_value(true)
+                .value_name("tabs")
+                .validator(
+                    |t| t.parse::<u32>()
+                        .map_err(|_t| "must be a number")
+                        .map(|_t| ()) // Convert to Result<(), &str>
+                        .map_err(|e| e.to_string()) // Convert to Result<(), String>
+                )
+                .help("Sets the tab width.")
+                .long_help("Sets the tab width. Use a width of 0 to pass tabs through \
+                        directly"),
+        ).arg(
+            Arg::with_name("terminal-width")
+                .long("terminal-width")
+                .takes_value(true)
+                .value_name("width")
+                .hidden(true)
+                .help("Set the width of the terminal"),
+        ).subcommand(
+            SubCommand::with_name("cache")
+                .about("Modify the syntax-definition and theme cache")
+                .arg(
+                    Arg::with_name("init")
+                        .long("init")
+                        .short("i")
+                        .help("Initialize the syntax/theme cache.")
+                        .long_help(
+                            "Initialize the syntax/theme cache by loading from the \
+                                 source directory (default: the configuration directory).",
+                        ),
+                ).arg(
+                Arg::with_name("clear")
+                    .long("clear")
+                    .short("c")
+                    .help("Remove the cached syntax definitions and themes."),
+            ).arg(
+                Arg::with_name("config-dir")
+                    .long("config-dir")
+                    .short("d")
+                    .help("Show bat's configuration directory."),
+            ).group(
+                ArgGroup::with_name("cache-actions")
+                    .args(&["init", "clear", "config-dir"])
+                    .required(arg_group_required),
+            ).arg(
+                Arg::with_name("source")
+                    .long("source")
+                    .requires("init")
+                    .takes_value(true)
+                    .value_name("dir")
+                    .help("Use a different directory to load syntaxes and themes from."),
+            ).arg(
+                Arg::with_name("target")
+                    .long("target")
+                    .requires("init")
+                    .takes_value(true)
+                    .value_name("dir")
+                    .help(
+                        "Use a different directory to store the cached syntax and theme set.",
                     ),
             ).arg(
-                Arg::with_name("terminal-width")
-                    .long("terminal-width")
-                    .takes_value(true)
-                    .value_name("width")
-                    .hidden(true)
-                    .help("Set the width of the terminal"),
-            ).subcommand(
-                SubCommand::with_name("cache")
-                    .about("Modify the syntax-definition and theme cache")
-                    .arg(
-                        Arg::with_name("init")
-                            .long("init")
-                            .short("i")
-                            .help("Initialize the syntax/theme cache.")
-                            .long_help(
-                                "Initialize the syntax/theme cache by loading from the \
-                                 source directory (default: the configuration directory).",
-                            ),
-                    ).arg(
-                        Arg::with_name("clear")
-                            .long("clear")
-                            .short("c")
-                            .help("Remove the cached syntax definitions and themes."),
-                    ).arg(
-                        Arg::with_name("config-dir")
-                            .long("config-dir")
-                            .short("d")
-                            .help("Show bat's configuration directory."),
-                    ).group(
-                        ArgGroup::with_name("cache-actions")
-                            .args(&["init", "clear", "config-dir"])
-                            .required(arg_group_required),
-                    ).arg(
-                        Arg::with_name("source")
-                            .long("source")
-                            .requires("init")
-                            .takes_value(true)
-                            .value_name("dir")
-                            .help("Use a different directory to load syntaxes and themes from."),
-                    ).arg(
-                        Arg::with_name("target")
-                            .long("target")
-                            .requires("init")
-                            .takes_value(true)
-                            .value_name("dir")
-                            .help(
-                                "Use a different directory to store the cached syntax and theme set.",
-                            ),
-                    ).arg(
-                        Arg::with_name("blank")
-                            .long("blank")
-                            .requires("init")
-                            .help("Create completely new syntax and theme sets \
+                Arg::with_name("blank")
+                    .long("blank")
+                    .requires("init")
+                    .help("Create completely new syntax and theme sets \
                                    (instead of appending to the default sets).")
-                    ),
-            ).help_message("Print this help message.")
+            ),
+        ).help_message("Print this help message.")
             .version_message("Show version information.")
             .get_matches()
     }
@@ -341,6 +359,27 @@ impl App {
         let files = self.files();
         let output_components = self.output_components()?;
 
+        let paging_mode = match self.matches.value_of("paging") {
+            Some("always") => PagingMode::Always,
+            Some("never") => PagingMode::Never,
+            Some("auto") | _ => if files.contains(&InputFile::StdIn) {
+                // If we are reading from stdin, only enable paging if we write to an
+                // interactive terminal and if we do not *read* from an interactive
+                // terminal.
+                if self.interactive_output && !atty::is(Stream::Stdin) {
+                    PagingMode::QuitIfOneScreen
+                } else {
+                    PagingMode::Never
+                }
+            } else {
+                if self.interactive_output {
+                    PagingMode::QuitIfOneScreen
+                } else {
+                    PagingMode::Never
+                }
+            },
+        };
+
         Ok(Config {
             true_color: is_truecolor_terminal(),
             language: self.matches.value_of("language"),
@@ -364,26 +403,7 @@ impl App {
                 Some("never") => false,
                 Some("auto") | _ => self.interactive_output,
             },
-            paging_mode: match self.matches.value_of("paging") {
-                Some("always") => PagingMode::Always,
-                Some("never") => PagingMode::Never,
-                Some("auto") | _ => if files.contains(&InputFile::StdIn) {
-                    // If we are reading from stdin, only enable paging if we write to an
-                    // interactive terminal and if we do not *read* from an interactive
-                    // terminal.
-                    if self.interactive_output && !atty::is(Stream::Stdin) {
-                        PagingMode::QuitIfOneScreen
-                    } else {
-                        PagingMode::Never
-                    }
-                } else {
-                    if self.interactive_output {
-                        PagingMode::QuitIfOneScreen
-                    } else {
-                        PagingMode::Never
-                    }
-                },
-            },
+            paging_mode,
             term_width: self
                 .matches
                 .value_of("terminal-width")
@@ -393,6 +413,19 @@ impl App {
                 || self.matches.value_of("color") == Some("always")
                 || self.matches.value_of("decorations") == Some("always")),
             files,
+            tab_width: self
+                .matches
+                .value_of("tabs")
+                .map(String::from)
+                .or_else(|| env::var("BAT_TABS").ok())
+                .and_then(|t| t.parse().ok())
+                .unwrap_or(
+                    if output_components.plain() && paging_mode == PagingMode::Never {
+                        0
+                    } else {
+                        8
+                    },
+                ),
             theme: self
                 .matches
                 .value_of("theme")

src/main.rs

@@ -24,6 +24,7 @@ mod decorations;
 mod diff;
 mod line_range;
 mod output;
+mod preprocessor;
 mod printer;
 mod style;
 mod terminal;

src/preprocessor.rs

@@ -0,0 +1,34 @@
+use console::AnsiCodeIterator;
+
+/// Expand tabs like an ANSI-enabled expand(1).
+pub fn expand(line: &str, width: usize, cursor: &mut usize) -> String {
+    let mut buffer = String::with_capacity(line.len() * 2);
+
+    for chunk in AnsiCodeIterator::new(line) {
+        match chunk {
+            (text, true) => buffer.push_str(text),
+            (mut text, false) => {
+                while let Some(index) = text.find('\t') {
+                    // Add previous text.
+                    if index > 0 {
+                        *cursor += index;
+                        buffer.push_str(&text[0..index]);
+                    }
+
+                    // Add tab.
+                    let spaces = width - (*cursor % width);
+                    *cursor += spaces;
+                    buffer.push_str(&*" ".repeat(spaces));
+
+                    // Next.
+                    text = &text[index + 1..text.len()];
+                }
+
+                *cursor += text.len();
+                buffer.push_str(text);
+            }
+        }
+    }
+
+    buffer
+}

src/printer.rs

@@ -16,6 +16,7 @@ use decorations::{Decoration, GridBorderDecoration, LineChangesDecoration, LineN
 use diff::get_git_diff;
 use diff::LineChanges;
 use errors::*;
+use preprocessor::expand;
 use style::OutputWrap;
 use terminal::{as_terminal_escaped, to_ansi_color};
 
@@ -152,6 +153,14 @@ impl<'a> InteractivePrinter<'a> {
 
         Ok(())
     }
+
+    fn preprocess(&self, text: &str, cursor: &mut usize) -> String {
+        if self.config.tab_width > 0 {
+            expand(text, self.config.tab_width, cursor)
+        } else {
+            text.to_string()
+        }
+    }
 }
 
 impl<'a> Printer for InteractivePrinter<'a> {
@@ -204,7 +213,7 @@ impl<'a> Printer for InteractivePrinter<'a> {
         line_number: usize,
         line_buffer: &[u8],
     ) -> Result<()> {
-        let line = String::from_utf8_lossy(&line_buffer);
+        let line = String::from_utf8_lossy(&line_buffer).to_string();
         let regions = self.highlighter.highlight(line.as_ref());
 
         if out_of_range {
@@ -213,6 +222,7 @@ impl<'a> Printer for InteractivePrinter<'a> {
 
         let mut cursor: usize = 0;
         let mut cursor_max: usize = self.config.term_width;
+        let mut cursor_total: usize = 0;
         let mut panel_wrap: Option<String> = None;
 
         // Line decorations.
@@ -234,19 +244,14 @@ impl<'a> Printer for InteractivePrinter<'a> {
             let true_color = self.config.true_color;
             let colored_output = self.config.colored_output;
 
-            write!(
-                handle,
-                "{}",
-                regions
-                    .iter()
-                    .map(|&(style, text)| as_terminal_escaped(
-                        style,
-                        text,
-                        true_color,
-                        colored_output,
-                    )).collect::<Vec<_>>()
-                    .join("")
-            )?;
+            for &(style, region) in regions.iter() {
+                let text = &*self.preprocess(region, &mut cursor_total);
+                write!(
+                    handle,
+                    "{}",
+                    as_terminal_escaped(style, &*text, true_color, colored_output,)
+                )?;
+            }
 
             if line.bytes().next_back() != Some(b'\n') {
                 write!(handle, "\n")?;
@@ -273,7 +278,11 @@ impl<'a> Printer for InteractivePrinter<'a> {
 
                         // Regular text.
                         (text, false) => {
-                            let text = text.trim_right_matches(|c| c == '\r' || c == '\n');
+                            let text = self.preprocess(
+                                text.trim_right_matches(|c| c == '\r' || c == '\n'),
+                                &mut cursor_total,
+                            );
+
                             let mut chars = text.chars();
                             let mut remaining = text.chars().count();
 

tests/snapshots/generate_snapshots.py

@@ -1,43 +1,64 @@
 #!/usr/bin/env python3
+
 import itertools
 import subprocess
 import pathlib
 import shutil
 
+
 def generate_snapshots():
     single_styles = ["changes", "grid", "header", "numbers"]
     collective_styles = ["full", "plain"]
 
     for num in range(len(single_styles)):
         for grouped in itertools.combinations(single_styles, num + 1):
-            generate_snapshot(",".join(grouped))
+            generate_style_snapshot(",".join(grouped))
 
     for style in collective_styles:
-        generate_snapshot(style)
+        generate_style_snapshot(style)
 
-def generate_snapshot(option):
-    command = "../../target/debug/bat --style={0} sample.rs > output/{0}.snapshot.txt".format(
-        option
+    generate_snapshot("tabs_passthrough", "--tabs=0 --style=full --wrap=never")
+    generate_snapshot("tabs_passthrough_wrapped", "--tabs=0 --style=full --wrap=character")
+    generate_snapshot("tabs_4", "--tabs=4 --style=full --wrap=never")
+    generate_snapshot("tabs_4_wrapped", "--tabs=4 --style=full --wrap=character")
+    generate_snapshot("tabs_8", "--tabs=8 --style=full --wrap=never")
+    generate_snapshot("tabs_8_wrapped", "--tabs=8 --style=full --wrap=character")
+
+
+def generate_style_snapshot(style):
+    generate_snapshot(style.replace(",", "_"), "--style={}".format(style))
+
+
+def generate_snapshot(name, arguments):
+    command = "cargo run -- --paging=never --color=never --decorations=always "
+    command += "{args} sample.rs > output/{name}.snapshot.txt".format(
+        name=name,
+        args=arguments
     )
-    print("generating snapshot for {}".format(option))
+    print("generating snapshot for {}".format(name))
     subprocess.call(command, shell=True)
 
+
 def build_bat():
     print("building bat")
     subprocess.call("cargo build", cwd="../..", shell=True)
 
+
 def prepare_output_dir():
     shutil.rmtree("output", ignore_errors=True)
     pathlib.Path("output").mkdir()
 
+
 def modify_sample_file():
     print("modifying sample.rs to show changes")
     shutil.copyfile("sample.modified.rs", "sample.rs")
 
+
 def undo_sample_file_modification():
     print("undoing sample.rs modifications")
     subprocess.call("git checkout -- sample.rs", shell=True)
 
+
 build_bat()
 prepare_output_dir()
 modify_sample_file()

tests/snapshots/output/changes.snapshot.txt

@@ -16,7 +16,21 @@ _ fn main() {
   fn area(rectangle: &Rectangle) -> u32 {
       rectangle.width * rectangle.height
   }
-+ 
+  
 + fn perimeter(rectangle: &Rectangle) -> u32 {
 +     (rectangle.width + rectangle.height) * 2
 + }
++ 
+  // Tab alignment:
+  /*
+          Indent
+          1       2       3       4
+  1       ?
+  22      ?
+  333     ?
+  4444    ?
+  55555   ?
+  666666  ?
+  7777777 ?
+  88888888        ?
+~ */

tests/snapshots/output/changes_grid.snapshot.txt

@@ -16,8 +16,22 @@ _ │ fn main() {
   │ fn area(rectangle: &Rectangle) -> u32 {
   │     rectangle.width * rectangle.height
   │ }
-+ │ 
+  │ 
 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
 + │     (rectangle.width + rectangle.height) * 2
 + │ }
++ │ 
+  │ // Tab alignment:
+  │ /*
+  │         Indent
+  │         1       2       3       4
+  │ 1       ?
+  │ 22      ?
+  │ 333     ?
+  │ 4444    ?
+  │ 55555   ?
+  │ 666666  ?
+  │ 7777777 ?
+  │ 88888888        ?
+~ │ */
 ──┴─────────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes_grid_header.snapshot.txt

@@ -19,8 +19,22 @@ _ │ fn main() {
   │ fn area(rectangle: &Rectangle) -> u32 {
   │     rectangle.width * rectangle.height
   │ }
-+ │ 
+  │ 
 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
 + │     (rectangle.width + rectangle.height) * 2
 + │ }
++ │ 
+  │ // Tab alignment:
+  │ /*
+  │         Indent
+  │         1       2       3       4
+  │ 1       ?
+  │ 22      ?
+  │ 333     ?
+  │ 4444    ?
+  │ 55555   ?
+  │ 666666  ?
+  │ 7777777 ?
+  │ 88888888        ?
+~ │ */
 ──┴─────────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes_grid_header_numbers.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "<22><><EFBFBD><EFBFBD><EFBFBD>"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes_grid_numbers.snapshot.txt

@@ -16,8 +16,22 @@
   16   │ fn area(rectangle: &Rectangle) -> u32 {
   17   │     rectangle.width * rectangle.height
   18   │ }
-  19 + │ 
+  19   │ 
   20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 + │     (rectangle.width + rectangle.height) * 2
   22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
 ───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/changes_header.snapshot.txt

@@ -17,7 +17,21 @@ _ fn main() {
   fn area(rectangle: &Rectangle) -> u32 {
       rectangle.width * rectangle.height
   }
-+ 
+  
 + fn perimeter(rectangle: &Rectangle) -> u32 {
 +     (rectangle.width + rectangle.height) * 2
 + }
++ 
+  // Tab alignment:
+  /*
+          Indent
+          1       2       3       4
+  1       ?
+  22      ?
+  333     ?
+  4444    ?
+  55555   ?
+  666666  ?
+  7777777 ?
+  88888888        ?
+~ */

tests/snapshots/output/changes_header_numbers.snapshot.txt

@@ -17,7 +17,21 @@
   16   fn area(rectangle: &Rectangle) -> u32 {
   17       rectangle.width * rectangle.height
   18   }
-  19 + 
+  19   
   20 + fn perimeter(rectangle: &Rectangle) -> u32 {
   21 +     (rectangle.width + rectangle.height) * 2
   22 + }
+  23 + 
+  24   // Tab alignment:
+  25   /*
+  26           Indent
+  27           1       2       3       4
+  28   1       ?
+  29   22      ?
+  30   333     ?
+  31   4444    ?
+  32   55555   ?
+  33   666666  ?
+  34   7777777 ?
+  35   88888888        ?
+  36 ~ */

tests/snapshots/output/changes_numbers.snapshot.txt

@@ -16,7 +16,21 @@
   16   fn area(rectangle: &Rectangle) -> u32 {
   17       rectangle.width * rectangle.height
   18   }
-  19 + 
+  19   
   20 + fn perimeter(rectangle: &Rectangle) -> u32 {
   21 +     (rectangle.width + rectangle.height) * 2
   22 + }
+  23 + 
+  24   // Tab alignment:
+  25   /*
+  26           Indent
+  27           1       2       3       4
+  28   1       ?
+  29   22      ?
+  30   333     ?
+  31   4444    ?
+  32   55555   ?
+  33   666666  ?
+  34   7777777 ?
+  35   88888888        ?
+  36 ~ */

tests/snapshots/output/full.snapshot.txt

@@ -19,8 +19,22 @@
   16   │ fn area(rectangle: &Rectangle) -> u32 {
   17   │     rectangle.width * rectangle.height
   18   │ }
-  19 + │ 
+  19   │ 
   20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 + │     (rectangle.width + rectangle.height) * 2
   22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
 ───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/grid.snapshot.txt

@@ -20,4 +20,18 @@ fn area(rectangle: &Rectangle) -> u32 {
 fn perimeter(rectangle: &Rectangle) -> u32 {
     (rectangle.width + rectangle.height) * 2
 }
+
+// Tab alignment:
+/*
+        Indent
+        1       2       3       4
+1       ?
+22      ?
+333     ?
+4444    ?
+55555   ?
+666666  ?
+7777777 ?
+88888888        ?
+*/
 ────────────────────────────────────────────────────────────────────────────────

tests/snapshots/output/grid_header.snapshot.txt

@@ -23,4 +23,18 @@ fn area(rectangle: &Rectangle) -> u32 {
 fn perimeter(rectangle: &Rectangle) -> u32 {
     (rectangle.width + rectangle.height) * 2
 }
+
+// Tab alignment:
+/*
+        Indent
+        1       2       3       4
+1       ?
+22      ?
+333     ?
+4444    ?
+55555   ?
+666666  ?
+7777777 ?
+88888888        ?
+*/
 ────────────────────────────────────────────────────────────────────────────────

tests/snapshots/output/grid_header_numbers.snapshot.txt

@@ -23,4 +23,18 @@
   20 │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 │     (rectangle.width + rectangle.height) * 2
   22 │ }
+  23 │ 
+  24 │ // Tab alignment:
+  25 │ /*
+  26 │         Indent
+  27 │         1       2       3       4
+  28 │ 1       ?
+  29 │ 22      ?
+  30 │ 333     ?
+  31 │ 4444    ?
+  32 │ 55555   ?
+  33 │ 666666  ?
+  34 │ 7777777 ?
+  35 │ 88888888        ?
+  36 │ */
 ─────┴──────────────────────────────────────────────────────────────────────────

tests/snapshots/output/grid_numbers.snapshot.txt

@@ -20,4 +20,18 @@
   20 │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 │     (rectangle.width + rectangle.height) * 2
   22 │ }
+  23 │ 
+  24 │ // Tab alignment:
+  25 │ /*
+  26 │         Indent
+  27 │         1       2       3       4
+  28 │ 1       ?
+  29 │ 22      ?
+  30 │ 333     ?
+  31 │ 4444    ?
+  32 │ 55555   ?
+  33 │ 666666  ?
+  34 │ 7777777 ?
+  35 │ 88888888        ?
+  36 │ */
 ─────┴──────────────────────────────────────────────────────────────────────────

tests/snapshots/output/header.snapshot.txt

@@ -21,3 +21,17 @@ fn area(rectangle: &Rectangle) -> u32 {
 fn perimeter(rectangle: &Rectangle) -> u32 {
     (rectangle.width + rectangle.height) * 2
 }
+
+// Tab alignment:
+/*
+        Indent
+        1       2       3       4
+1       ?
+22      ?
+333     ?
+4444    ?
+55555   ?
+666666  ?
+7777777 ?
+88888888        ?
+*/

tests/snapshots/output/header_numbers.snapshot.txt

@@ -21,3 +21,17 @@
   20 fn perimeter(rectangle: &Rectangle) -> u32 {
   21     (rectangle.width + rectangle.height) * 2
   22 }
+  23 
+  24 // Tab alignment:
+  25 /*
+  26         Indent
+  27         1       2       3       4
+  28 1       ?
+  29 22      ?
+  30 333     ?
+  31 4444    ?
+  32 55555   ?
+  33 666666  ?
+  34 7777777 ?
+  35 88888888        ?
+  36 */

tests/snapshots/output/numbers.snapshot.txt

@@ -20,3 +20,17 @@
   20 fn perimeter(rectangle: &Rectangle) -> u32 {
   21     (rectangle.width + rectangle.height) * 2
   22 }
+  23 
+  24 // Tab alignment:
+  25 /*
+  26         Indent
+  27         1       2       3       4
+  28 1       ?
+  29 22      ?
+  30 333     ?
+  31 4444    ?
+  32 55555   ?
+  33 666666  ?
+  34 7777777 ?
+  35 88888888        ?
+  36 */

tests/snapshots/output/plain.snapshot.txt

@@ -20,3 +20,17 @@ fn area(rectangle: &Rectangle) -> u32 {
 fn perimeter(rectangle: &Rectangle) -> u32 {
     (rectangle.width + rectangle.height) * 2
 }
+
+// Tab alignment:
+/*
+	Indent
+	1	2	3	4
+1	?
+22	?
+333	?
+4444	?
+55555	?
+666666	?
+7777777	?
+88888888	?
+*/

tests/snapshots/output/tabs_4.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "<22><><EFBFBD><EFBFBD><EFBFBD>"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │     Indent
+  27   │     1   2   3   4
+  28   │ 1   ?
+  29   │ 22  ?
+  30   │ 333 ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888    ?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/tabs_4_wrapped.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "<22><><EFBFBD><EFBFBD><EFBFBD>"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │     Indent
+  27   │     1   2   3   4
+  28   │ 1   ?
+  29   │ 22  ?
+  30   │ 333 ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888    ?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/tabs_8.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "<22><><EFBFBD><EFBFBD><EFBFBD>"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/tabs_8_wrapped.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "<22><><EFBFBD><EFBFBD><EFBFBD>"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │         Indent
+  27   │         1       2       3       4
+  28   │ 1       ?
+  29   │ 22      ?
+  30   │ 333     ?
+  31   │ 4444    ?
+  32   │ 55555   ?
+  33   │ 666666  ?
+  34   │ 7777777 ?
+  35   │ 88888888        ?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/tabs_passthrough.snapshot.txt

@@ -19,8 +19,22 @@
   16   │ fn area(rectangle: &Rectangle) -> u32 {
   17   │     rectangle.width * rectangle.height
   18   │ }
-  19 + │ 
+  19   │ 
   20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
   21 + │     (rectangle.width + rectangle.height) * 2
   22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │ 	Indent
+  27   │ 	1	2	3	4
+  28   │ 1	?
+  29   │ 22	?
+  30   │ 333	?
+  31   │ 4444	?
+  32   │ 55555	?
+  33   │ 666666	?
+  34   │ 7777777	?
+  35   │ 88888888	?
+  36 ~ │ */
 ───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/output/tabs_passthrough_wrapped.snapshot.txt

@@ -0,0 +1,40 @@
+───────┬────────────────────────────────────────────────────────────────────────
+       │ File: sample.rs
+───────┼────────────────────────────────────────────────────────────────────────
+   1   │ struct Rectangle {
+   2   │     width: u32,
+   3   │     height: u32,
+   4   │ }
+   5   │ 
+   6 _ │ fn main() {
+   7   │     let rect1 = Rectangle { width: 30, height: 50 };
+   8   │ 
+   9   │     println!(
+  10 ~ │         "The perimeter of the rectangle is {} pixels.",
+  11 ~ │         perimeter(&rect1)
+  12   │     );
+  13 + │     println!(r#"This line contains invalid utf8:  "<22><><EFBFBD><EFBFBD><EFBFBD>"#;
+  14   │ }
+  15   │ 
+  16   │ fn area(rectangle: &Rectangle) -> u32 {
+  17   │     rectangle.width * rectangle.height
+  18   │ }
+  19   │ 
+  20 + │ fn perimeter(rectangle: &Rectangle) -> u32 {
+  21 + │     (rectangle.width + rectangle.height) * 2
+  22 + │ }
+  23 + │ 
+  24   │ // Tab alignment:
+  25   │ /*
+  26   │ 	Indent
+  27   │ 	1	2	3	4
+  28   │ 1	?
+  29   │ 22	?
+  30   │ 333	?
+  31   │ 4444	?
+  32   │ 55555	?
+  33   │ 666666	?
+  34   │ 7777777	?
+  35   │ 88888888	?
+  36 ~ │ */
+───────┴────────────────────────────────────────────────────────────────────────

tests/snapshots/sample.modified.rs

@@ -20,3 +20,17 @@ fn area(rectangle: &Rectangle) -> u32 {
 fn perimeter(rectangle: &Rectangle) -> u32 {
     (rectangle.width + rectangle.height) * 2
 }
+
+// Tab alignment:
+/*
+	Indent
+	1	2	3	4
+1	?
+22	?
+333	?
+4444	?
+55555	?
+666666	?
+7777777	?
+88888888	?
+*/

tests/snapshots/sample.rs

@@ -16,3 +16,17 @@ fn main() {
 fn area(rectangle: &Rectangle) -> u32 {
     rectangle.width * rectangle.height
 }
+
+// Tab alignment:
+/*
+	Indent
+	1	2	3	4
+1	?
+22	?
+333	?
+4444	?
+55555	?
+666666	?
+7777777	?
+88888888	?
+*/

tests/tester.rs

@@ -38,13 +38,17 @@ impl BatTester {
         BatTester { temp_dir, exe }
     }
 
-    pub fn test_snapshot(&self, style: &str) {
+    pub fn test_snapshot(&self, name: &str, style: &str, tab_width: u32, wrap: bool) {
         let output = Command::new(&self.exe)
             .current_dir(self.temp_dir.path())
             .args(&[
                 "sample.rs",
+                "--paging=never",
+                "--color=never",
                 "--decorations=always",
                 "--terminal-width=80",
+                &format!("--wrap={}", if wrap { "character" } else { "never" }),
+                &format!("--tabs={}", tab_width),
                 &format!("--style={}", style),
             ]).output()
             .expect("bat failed");
@@ -55,7 +59,7 @@ impl BatTester {
             .replace("tests/snapshots/", "");
 
         let mut expected = String::new();
-        let mut file = File::open(format!("tests/snapshots/output/{}.snapshot.txt", style))
+        let mut file = File::open(format!("tests/snapshots/output/{}.snapshot.txt", name))
             .expect("snapshot file missing");
         file.read_to_string(&mut expected)
             .expect("could not read snapshot file");

tests/tests.rs

@@ -3,33 +3,39 @@ mod tester;
 use tester::BatTester;
 
 macro_rules! snapshot_tests {
-    ($($test_name: ident: $style: expr,)*) => {
+    ($($test_name: ident: $style: expr => [wrap: $wrap:expr, tabs: $tabs:expr],)*) => {
         $(
             #[test]
             fn $test_name() {
                 let bat_tester = BatTester::new();
-                bat_tester.test_snapshot($style);
+                bat_tester.test_snapshot(stringify!($test_name), $style, $tabs, $wrap);
             }
         )*
     };
 }
 
 snapshot_tests! {
-    changes: "changes",
-    grid: "grid",
-    header: "header",
-    numbers: "numbers",
-    changes_grid: "changes,grid",
-    changes_header: "changes,header",
-    changes_numbers: "changes,numbers",
-    grid_header: "grid,header",
-    grid_numbers: "grid,numbers",
-    header_numbers: "header,numbers",
-    changes_grid_header: "changes,grid,header",
-    changes_grid_numbers: "changes,grid,numbers",
-    changes_header_numbers: "changes,header,numbers",
-    grid_header_numbers: "grid,header,numbers",
-    changes_grid_header_numbers: "changes,grid,header,numbers",
-    full: "full",
-    plain: "plain",
+    changes:                     "changes"                     => [wrap: false, tabs: 8],
+    grid:                        "grid"                        => [wrap: false, tabs: 8],
+    header:                      "header"                      => [wrap: false, tabs: 8],
+    numbers:                     "numbers"                     => [wrap: false, tabs: 8],
+    changes_grid:                "changes,grid"                => [wrap: false, tabs: 8],
+    changes_header:              "changes,header"              => [wrap: false, tabs: 8],
+    changes_numbers:             "changes,numbers"             => [wrap: false, tabs: 8],
+    grid_header:                 "grid,header"                 => [wrap: false, tabs: 8],
+    grid_numbers:                "grid,numbers"                => [wrap: false, tabs: 8],
+    header_numbers:              "header,numbers"              => [wrap: false, tabs: 8],
+    changes_grid_header:         "changes,grid,header"         => [wrap: false, tabs: 8],
+    changes_grid_numbers:        "changes,grid,numbers"        => [wrap: false, tabs: 8],
+    changes_header_numbers:      "changes,header,numbers"      => [wrap: false, tabs: 8],
+    grid_header_numbers:         "grid,header,numbers"         => [wrap: false, tabs: 8],
+    changes_grid_header_numbers: "changes,grid,header,numbers" => [wrap: false, tabs: 8],
+    full:                        "full"                        => [wrap: false, tabs: 8],
+    plain:                       "plain"                       => [wrap: false, tabs: 0],
+    tabs_passthrough_wrapped:    "full"                        => [wrap: true,  tabs: 0],
+    tabs_4_wrapped:              "full"                        => [wrap: true,  tabs: 4],
+    tabs_8_wrapped:              "full"                        => [wrap: true,  tabs: 8],
+    tabs_passthrough:            "full"                        => [wrap: false, tabs: 0],
+    tabs_4:                      "full"                        => [wrap: false, tabs: 4],
+    tabs_8:                      "full"                        => [wrap: false, tabs: 8],
 }