batdiff: Add batdiff script

README.md

@@ -25,6 +25,12 @@ Watch for changes in one or more files, and print them with `bat`.
 
 
 
+### [`batdiff`](doc/batgrep.md)
+Diff a file against the current git index, or display the diff between two files.
+<u>Requirements:</u> `bat`, `delta` (optional)
+
+
+
 ### [`prettybat`](doc/prettybat.md)
 
 Pretty-print source code and highlight it with `bat`.

doc/batdiff.md

@@ -0,0 +1,55 @@
+# bat-extras: batdiff
+
+Diff a file against the current git index, or display the diff between two files.
+
+This script supports using [delta](https://github.com/dandavison/delta) as an alternative highlighter for diffs.
+
+
+
+
+## Command Line
+
+**Synopsis:**
+
+- `batdiff [OPTIONS] FILE`
+- `batdiff [OPTIONS] FILE OTHER_FILE`
+
+
+
+**Options:**
+
+| Short | Long                      | Description                                                  |
+| ----- | ------------------------- | ------------------------------------------------------------ |
+| `-C`  | `--context=[LINES]`       | The number of lines to show before and after the differing lines. |
+|       | `--delta`                 | Display diffs using `delta`.                                 |
+|       | `--color`                 | Force color output.                                          |
+|       | `--no-color`              | Force disable color output.                                  |
+|       | `--paging=["never"|"always"]`| Enable/disable paging.                                    |
+|       | `--pager=[PAGER]`         | Specify the pager to use.                                   |
+|       | `--terminal-width=[COLS]` | Generate output for the specified terminal width.            |
+
+
+
+## Installation
+
+This script is a part of the `bat-extras` suite of scripts. You can find install instructions [here](../README.md#installation).
+
+
+
+## Caveats
+
+**When using `bat` as the printer:**
+
+- Syntax highlighting in diffs between two files is not supported.
+- Syntax highlighting in a single-file diff requires `bat` >= 0.15.
+
+**When using `delta` as the printer:**
+
+- The `--no-color` option does not remove all color output.
+
+
+
+## Issues?
+
+If you find an issue or have a feature suggestion, make a pull request or issue through GitHub!
+Contributions are always welcome.

lib/constants.sh

@@ -7,6 +7,7 @@
 # -----------------------------------------------------------------------------
 EXECUTABLE_BAT="bat"
 EXECUTABLE_GIT="git"
+EXECUTABLE_DELTA="delta"
 PROGRAM="$(basename "$0" .sh)"
 PROGRAM_HOMEPAGE="https://github.com/eth-p/bat-extras"
 PROGRAM_COPYRIGHT="Copyright (C) 2019-2020 eth-p | MIT License"

lib/opt_hook_width.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# -----------------------------------------------------------------------------
+# bat-extras | Copyright (C) 2019 eth-p | MIT License
+#
+# Repository: https://github.com/eth-p/bat-extras
+# Issues:     https://github.com/eth-p/bat-extras/issues
+# -----------------------------------------------------------------------------
+
+# Option parser hook: --terminal-width support.
+# This will accept --terminal-width=number.
+#
+# The variable OPT_TERMINAL_WIDTH will be set.
+hook_width() {
+	SHIFTOPT_HOOKS+=("__shiftopt_hook__width")
+	__shiftopt_hook__width() {
+		case "$OPT" in
+
+		--terminal-width) shiftval; OPT_TERMINAL_WIDTH="$OPT_VAL" ;;
+
+		*) return 1 ;;
+		esac
+		return 0
+	}
+
+	# Default terminal width.
+	OPT_TERMINAL_WIDTH="$(stty size | cut -d' ' -f 2)"
+}

src/batdiff.sh

@@ -0,0 +1,173 @@
+#!/usr/bin/env bash
+# -----------------------------------------------------------------------------
+# bat-extras | Copyright (C) 2020 eth-p | MIT License
+#
+# Repository: https://github.com/eth-p/bat-extras
+# Issues:     https://github.com/eth-p/bat-extras/issues
+# -----------------------------------------------------------------------------
+# shellcheck disable=SC1090
+LIB="$(cd "$(dirname "${BASH_SOURCE[0]}")" && cd "$(dirname "$(readlink "${BASH_SOURCE[0]}" || echo ".")")/../lib" && pwd)"
+source "${LIB}/constants.sh"
+source "${LIB}/print.sh"
+source "${LIB}/pager.sh"
+source "${LIB}/opt.sh"
+source "${LIB}/opt_hooks.sh"
+source "${LIB}/opt_hook_width.sh"
+source "${LIB}/version.sh"
+# -----------------------------------------------------------------------------
+# Init:
+# -----------------------------------------------------------------------------
+hook_color
+hook_pager
+hook_version
+hook_width
+# -----------------------------------------------------------------------------
+# Options:
+# -----------------------------------------------------------------------------
+BATDIFF_USE_DELTA="${BATDIFF_USE_DELTA:-}"
+
+SUPPORTS_BAT_DIFF=false
+SUPPORTS_DELTA=false
+
+BAT_VERSION="$(bat_version)"
+BAT_ARGS=()
+DELTA_ARGS=()
+
+FILES=()
+OPT_TABS=
+OPT_CONTEXT=2
+OPT_ALL_CHANGES=false
+
+# Set options based on bat version.
+if version_compare "$BAT_VERSION" -ge "0.15"; then
+	SUPPORTS_BAT_DIFF=true
+fi
+
+# Set options based on delta availability.
+if command -v "$EXECUTABLE_DELTA" &>/dev/null; then
+	SUPPORTS_DELTA=true
+fi
+
+# Parse arguments.
+while shiftopt; do
+	case "$OPT" in
+
+	# bat options
+	-C | --context | --diff-context)   shiftval; OPT_CONTEXT="$OPT_VAL" ;;
+	--terminal-width)                  shiftval; OPT_TERMINAL_WIDTH="$OPT_VAL" ;;
+	--tabs)                            shiftval; OPT_TABS="$OPT_VAL" ;;
+
+	# Script options
+	--all)                      OPT_ALL_CHANGES=true ;;
+	--delta)                    BATDIFF_USE_DELTA=true ;;
+
+	# ???
+	-*) {
+		printc "%{RED}%s: unknown option '%s'%{CLEAR}\n" "$PROGRAM" "$OPT" 1>&2
+		exit 1
+	} ;;
+
+	# Files
+	*) FILES+=("$OPT") ;;
+
+	esac
+done
+
+# Append arguments for delta/bat.
+BAT_ARGS+=("--terminal-width=${OPT_TERMINAL_WIDTH}" "--paging=never")
+DELTA_ARGS+=("--width=${OPT_TERMINAL_WIDTH}" "--paging=never" "--hunk-style=plain")
+
+if "$OPT_COLOR"; then
+	BAT_ARGS+=("--color=always")
+else
+	BAT_ARGS+=("--color=never")
+	DELTA_ARGS+=("--theme=none")
+fi
+
+if [[ -n "$OPT_TABS" ]]; then
+	BAT_ARGS+=("--tabs=${OPT_TABS}")
+	DELTA_ARGS+=("--tabs=${OPT_TABS}")
+fi
+
+# -----------------------------------------------------------------------------
+# Printing:
+# -----------------------------------------------------------------------------
+print_bat_diff() {
+	local files=("$@")
+
+	# Diff two files.
+	if [[ "${#files[@]}" -eq 2 ]]; then
+		diff --unified="$OPT_CONTEXT" "${files[@]}" | "$EXECUTABLE_BAT" --language=diff - "${BAT_ARGS[@]}"
+		return $?
+	fi
+
+	# Diff git file.
+	if "$SUPPORTS_BAT_DIFF"; then
+		"$EXECUTABLE_BAT" --diff --diff-context="$OPT_CONTEXT" "${files[0]}" "${BAT_ARGS[@]}"
+	else
+		"$EXECUTABLE_GIT" diff -U"$OPT_CONTEXT" "${files[0]}" | "$EXECUTABLE_BAT" --language=diff - "${BAT_ARGS[@]}"
+	fi
+}
+
+print_delta_diff() {
+	local files=("$@")
+
+	# Diff two files.
+	if [[ "${#files[@]}" -eq 2 ]]; then
+		diff --unified="$OPT_CONTEXT" "${files[@]}"  | "$EXECUTABLE_DELTA" "${DELTA_ARGS[@]}"
+		return $?
+	fi
+
+	# Diff git file.
+	"$EXECUTABLE_GIT" diff -U"$OPT_CONTEXT" "${files[0]}" | "$EXECUTABLE_DELTA" "${DELTA_ARGS[@]}"
+}
+
+if [[ "$BATDIFF_USE_DELTA" = "true" && "$SUPPORTS_DELTA" = "true" ]]; then
+	print_diff() {
+		print_delta_diff "$@"
+		return $?
+	}
+else
+	print_diff() {
+		print_bat_diff "$@"
+		return $?
+	}
+fi
+
+
+# -----------------------------------------------------------------------------
+# Validation:
+# -----------------------------------------------------------------------------
+
+# Handle no files.
+if [[ "${#FILES[@]}" -eq 0 ]] && ! "$OPT_ALL_CHANGES"; then
+	print_error "no files provided"
+	exit 1
+fi
+
+# Handle too many files.
+if [[ "${#FILES[@]}" -gt 2 ]]; then
+	print_error "too many files provided"
+	exit 1
+fi
+
+
+# -----------------------------------------------------------------------------
+# Main:
+# -----------------------------------------------------------------------------
+main() {
+	if "$OPT_ALL_CHANGES"; then
+		local file
+		while read -r file; do
+			if [[ -f "$file" ]]; then
+				print_diff "$file"
+			fi
+		done < <(git diff --name-only --diff-filter=d)
+		return
+	fi
+
+	print_diff "${FILES[@]}"
+}
+
+pager_exec main
+exit $?

test/shim/batdiff.sh

@@ -0,0 +1,3 @@
+batdiff() {
+	"${BIN_DIR}/batdiff${BIN_SUFFIX}" "$@" || return $?
+}

test/suite/batdiff.sh

@@ -0,0 +1,12 @@
+setup() {
+	use_shim 'batdiff'
+}
+
+test:version() {
+	description "Test 'batdiff --version'"
+	snapshot stdout
+	snapshot stderr
+
+	batdiff --version | awk 'FNR <= 1 { print $1 }'
+	batdiff --version | awk 'p{print} /^$/ { p=1 }'
+}