cmd: support dash as stdin alias

Author: ebraminio

doc/api/cli.md

@@ -10,7 +10,7 @@ To view this documentation as a manual page in a terminal, run `man node`.
 
 ## Synopsis
 
-`node [options] [v8 options] [script.js | -e "script"] [--] [arguments]`
+`node [options] [v8 options] [script.js | -e "script" | -] [--] [arguments]`
 
 `node debug [script.js | -e "script" | <host>:<port>] …`
 
@@ -345,6 +345,17 @@ added: v0.11.15
 
 Specify ICU data load path. (overrides `NODE_ICU_DATA`)
 
+
+### `-`
+<!-- YAML
+added: REPLACEME
+-->
+
+Alias for stdin, analogous to the use of - in other command line utilities,
+meaning that the script will be read from stdin, and the rest of the options
+are passed to that script.
+
+
 ### `--`
 <!-- YAML
 added: v7.5.0

doc/api/synopsis.md

@@ -2,7 +2,7 @@
 
 <!--type=misc-->
 
-`node [options] [v8 options] [script.js | -e "script"] [arguments]`
+`node [options] [v8 options] [script.js | -e "script" | - ] [arguments]`
 
 Please see the [Command Line Options][] document for information about
 different options and ways to run scripts with Node.js.

doc/node.1

@@ -36,7 +36,10 @@ node \- Server-side JavaScript runtime
 .RI [ v8\ options ]
 .RI [ script.js \ |
 .B -e
-.RI \&" script \&"]
+.RI \&" script \&"
+.R |
+.B -
+.R ]
 .B [--]
 .RI [ arguments ]
 .br
@@ -225,6 +228,12 @@ See \fBSSL_CERT_DIR\fR and \fBSSL_CERT_FILE\fR.
 .BR \-\-icu\-data\-dir =\fIfile\fR
 Specify ICU data load path. (overrides \fBNODE_ICU_DATA\fR)
 
+.TP
+.BR \-\fR
+Alias for stdin, analogous to the use of - in other command line utilities,
+meaning that the script will be read from stdin, and the rest of the options
+are passed to that script.
+
 .TP
 .BR \-\-\fR
 Indicate the end of node options. Pass the rest of the arguments to the script.

lib/internal/bootstrap_node.js

@@ -123,7 +123,7 @@
         const internalModule = NativeModule.require('internal/module');
         internalModule.addBuiltinLibsToObject(global);
         evalScript('[eval]');
-      } else if (process.argv[1]) {
+      } else if (process.argv[1] && process.argv[1] !== '-') {
         // make process.argv[1] into a full path
         const path = NativeModule.require('path');
         process.argv[1] = path.resolve(process.argv[1]);

src/node.cc

@@ -3586,7 +3586,7 @@ void LoadEnvironment(Environment* env) {
 static void PrintHelp() {
   // XXX: If you add an option here, please also add it to doc/node.1 and
   // doc/api/cli.md
-  printf("Usage: node [options] [ -e script | script.js ] [arguments]\n"
+  printf("Usage: node [options] [ -e script | script.js | - ] [arguments]\n"
          "       node inspect script.js [arguments]\n"
          "\n"
          "Options:\n"
@@ -3598,6 +3598,8 @@ static void PrintHelp() {
          "                             does not appear to be a terminal\n"
          "  -r, --require              module to preload (option can be "
          "repeated)\n"
+         "  -                          script read from stdin (default; "
+         "interactive mode if a tty)"
 #if HAVE_INSPECTOR
          "  --inspect[=[host:]port]    activate inspector on host:port\n"
          "                             (default: 127.0.0.1:9229)\n"
@@ -3903,6 +3905,8 @@ static void ParseArgs(int* argc,
     } else if (strcmp(arg, "--expose-internals") == 0 ||
                strcmp(arg, "--expose_internals") == 0) {
       config_expose_internals = true;
+    } else if (strcmp(arg, "-") == 0) {
+      break;
     } else if (strcmp(arg, "--") == 0) {
       index += 1;
       break;

test/parallel/test-stdin-script-child-option.js

@@ -0,0 +1,17 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const expected = '--option-to-be-seen-on-child';
+
+const { spawn } = require('child_process');
+const child = spawn(process.execPath, ['-', expected], { stdio: 'pipe' });
+
+child.stdin.end('console.log(process.argv[2])');
+
+let actual = '';
+child.stdout.setEncoding('utf8');
+child.stdout.on('data', (chunk) => actual += chunk);
+child.stdout.on('end', common.mustCall(() => {
+  assert.strictEqual(actual.trim(), expected);
+}));

test/parallel/test-stdin-script-child.js

@@ -2,31 +2,32 @@
 const common = require('../common');
 const assert = require('assert');
 
-const spawn = require('child_process').spawn;
-const child = spawn(process.execPath, [], {
-  env: Object.assign(process.env, {
-    NODE_DEBUG: process.argv[2]
-  })
-});
-const wanted = `${child.pid}\n`;
-let found = '';
+const { spawn } = require('child_process');
+for (const args of [[], ['-']]) {
+  const child = spawn(process.execPath, args, {
+    env: Object.assign(process.env, {
+      NODE_DEBUG: process.argv[2]
+    })
+  });
+  const wanted = `${child.pid}\n`;
+  let found = '';
 
-child.stdout.setEncoding('utf8');
-child.stdout.on('data', function(c) {
-  found += c;
-});
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', function(c) {
+    found += c;
+  });
 
-child.stderr.setEncoding('utf8');
-child.stderr.on('data', function(c) {
-  console.error(`> ${c.trim().split(/\n/).join('\n> ')}`);
-});
+  child.stderr.setEncoding('utf8');
+  child.stderr.on('data', function(c) {
+    console.error(`> ${c.trim().split(/\n/).join('\n> ')}`);
+  });
 
-child.on('close', common.mustCall(function(c) {
-  assert.strictEqual(c, 0);
-  assert.strictEqual(found, wanted);
-  console.log('ok');
-}));
+  child.on('close', common.mustCall(function(c) {
+    assert.strictEqual(c, 0);
+    assert.strictEqual(found, wanted);
+  }));
 
-setTimeout(function() {
-  child.stdin.end('console.log(process.pid)');
-}, 1);
+  setTimeout(function() {
+    child.stdin.end('console.log(process.pid)');
+  }, 1);
+}