Add and document split option for CLI

Author: Planeshifter

lib/node_modules/@stdlib/string/truncate-middle/README.md

@@ -130,6 +130,7 @@ Options:
   -V,    --version             Print the package version.
          --len length          String length.
          --seq str             Custom replacement sequence. Default: '...'.
+         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.
 ```
 
 </section>
@@ -140,6 +141,20 @@ Options:
 
 <section class="notes">
 
+### Notes
+
+-   If the split separator is a [regular expression][mdn-regexp], ensure that the `split` option is either properly escaped or enclosed in quotes.
+
+    ```bash
+    # Not escaped...
+    $ echo -n $'Hello, World!\nBeep Boop Baz' | truncate-middle --len 6 --split /\r?\n/
+
+    # Escaped...
+    $ echo -n $'Hello, World!\nBeep Boop Baz' | truncate-middle --len 6 --split /\\r?\\n/
+    ```
+
+-   The implementation ignores trailing delimiters.
+
 </section>
 
 <!-- /.notes -->
@@ -158,6 +173,21 @@ $ truncate-middle 'Hello, World!' --len 6 --seq '!'
 Hel|d!
 ```
 
+To use as a [standard stream][standard-streams],
+
+```bash
+$ echo -n 'Hello, World!' | truncate-middle --len 8
+Hel...d!
+```
+
+By default, when used as a [standard stream][standard-streams], the implementation assumes newline-delimited data. To specify an alternative delimiter, set the `split` option.
+
+```bash
+$ echo -n 'Hello, World!\tBeep Boop' | truncate-middle --split '\t' --len 6 --seq '!'
+Hel|d!
+Bee|op
+```
+
 </section>
 
 <!-- /.examples -->
@@ -192,6 +222,10 @@ Hel|d!
 
 <section class="links">
 
+[standard-streams]: https://en.wikipedia.org/wiki/Standard_streams
+
+[mdn-regexp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
+
 <!-- <related-links> -->
 
 [@stdlib/string/truncate]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/string/truncate

lib/node_modules/@stdlib/string/truncate-middle/bin/cli

@@ -28,6 +28,8 @@ var CLI = require( '@stdlib/cli/ctor' );
 var stdin = require( '@stdlib/process/read-stdin' );
 var stdinStream = require( '@stdlib/streams/node/stdin' );
 var RE_EOL = require( '@stdlib/regexp/eol' ).REGEXP;
+var isRegExpString = require( '@stdlib/assert/is-regexp-string' );
+var reFromString = require( '@stdlib/utils/regexp-from-string' );
 var truncateMiddle = require( './../lib' );
 
 
@@ -40,6 +42,7 @@ var truncateMiddle = require( './../lib' );
 * @returns {void}
 */
 function main() {
+	var split;
 	var flags;
 	var args;
 	var cli;
@@ -67,6 +70,14 @@ function main() {
 
 	// Check if we are receiving data from `stdin`...
 	if ( !stdinStream.isTTY ) {
+		if ( flags.split ) {
+			if ( !isRegExpString( flags.split ) ) {
+				flags.split = '/'+flags.split+'/';
+			}
+			split = reFromString( flags.split );
+		} else {
+			split = RE_EOL;
+		}
 		return stdin( onRead );
 	}
 	if ( flags.seq ) {
@@ -89,7 +100,7 @@ function main() {
 		if ( error ) {
 			return cli.error( error );
 		}
-		lines = data.toString().split( RE_EOL );
+		lines = data.toString().split( split );
 		if ( flags.seq ) {
 			for ( i = 0; i < lines.length; i++ ) {
 				console.log( truncateMiddle( lines[ i ], len, flags.seq ) ); // eslint-disable-line no-console

lib/node_modules/@stdlib/string/truncate-middle/docs/usage.txt

@@ -7,3 +7,4 @@ Options:
   -V,    --version             Print the package version.
          --len length          String length.
          --seq str             Custom replacement sequence. Default: '...'.
+         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.

lib/node_modules/@stdlib/string/truncate-middle/etc/cli_opts.json

@@ -1,7 +1,8 @@
 {
 	"string": [
 		"len",
-		"seq"
+		"seq",
+		"split"
 	],
 	"boolean": [
 		"help",

lib/node_modules/@stdlib/string/truncate-middle/test/test.cli.js

@@ -235,6 +235,52 @@ tape( 'the command-line interface supports use as a standard stream (custom sequ
 	}
 });
 
+tape( 'the command-line interface supports specifying a custom delimiter when used as a standard stream (string)', opts, function test( t ) {
+	var cmd = [
+		'printf \'beep boop\tHello World!\'',
+		'|',
+		EXEC_PATH,
+		fpath,
+		'--split \'\t\'',
+		'--len=5'
+	];
+
+	exec( cmd.join( ' ' ), done );
+
+	function done( error, stdout, stderr ) {
+		if ( error ) {
+			t.fail( error.message );
+		} else {
+			t.strictEqual( stdout.toString(), 'b...p\nH...!\n', 'expected value' );
+			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
+		}
+		t.end();
+	}
+});
+
+tape( 'the command-line interface supports specifying a custom delimiter when used as a standard stream (regexp)', opts, function test( t ) {
+	var cmd = [
+		'printf \'beep boop\tHello World!\'',
+		'|',
+		EXEC_PATH,
+		fpath,
+		'--split=/\\\\t/',
+		'--len=5'
+	];
+
+	exec( cmd.join( ' ' ), done );
+
+	function done( error, stdout, stderr ) {
+		if ( error ) {
+			t.fail( error.message );
+		} else {
+			t.strictEqual( stdout.toString(), 'b...p\nH...!\n', 'expected value' );
+			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
+		}
+		t.end();
+	}
+});
+
 tape( 'when used as a standard stream, if an error is encountered when reading from `stdin`, the command-line interface prints an error and sets a non-zero exit code', opts, function test( t ) {
 	var script;
 	var opts;