test: decrease duration of test-cli-syntax

Previously, test/parallel/test-cli-syntax.js was spawning a lot of child
processes, but using spawnSync, which made the test run each child
process serially. This switches most of the test cases to use exec so
that they are asynchronous. Locally, the test went from > 5 seconds to
under 2 seconds.

PR-URL: #14187
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

test/parallel/test-cli-syntax.js

@@ -1,9 +1,9 @@
 'use strict';
 
-require('../common');
+const common = require('../common');
 const assert = require('assert');
-const spawnSync = require('child_process').spawnSync;
 const fixtures = require('../common/fixtures');
+const exec = require('child_process').exec;
 
 const node = process.execPath;
 
@@ -29,12 +29,13 @@ const notFoundRE = /^Error: Cannot find module/m;
   // loop each possible option, `-c` or `--check`
   syntaxArgs.forEach(function(args) {
     const _args = args.concat(file);
-    const c = spawnSync(node, _args, {encoding: 'utf8'});
 
-    // no output should be produced
-    assert.strictEqual(c.stdout, '', 'stdout produced');
-    assert.strictEqual(c.stderr, '', 'stderr produced');
-    assert.strictEqual(c.status, 0, `code == ${c.status}`);
+    const cmd = [node, ..._args].join(' ');
+    exec(cmd, common.mustCall((err, stdout, stderr) => {
+      assert.ifError(err);
+      assert.strictEqual(stdout, '', 'stdout produced');
+      assert.strictEqual(stderr, '', 'stderr produced');
+    }));
   });
 });
 
@@ -50,15 +51,20 @@ const notFoundRE = /^Error: Cannot find module/m;
   // loop each possible option, `-c` or `--check`
   syntaxArgs.forEach(function(args) {
     const _args = args.concat(file);
-    const c = spawnSync(node, _args, {encoding: 'utf8'});
+    const cmd = [node, ..._args].join(' ');
+    exec(cmd, common.mustCall((err, stdout, stderr) => {
+      assert.strictEqual(err instanceof Error, true);
+      assert.strictEqual(err.code, 1, `code === ${err.code}`);
 
-    // no stdout should be produced
-    assert.strictEqual(c.stdout, '', 'stdout produced');
+      // no stdout should be produced
+      assert.strictEqual(stdout, '', 'stdout produced');
 
-    // stderr should have a syntax error message
-    assert(syntaxErrorRE.test(c.stderr), 'stderr incorrect');
+      // stderr should have a syntax error message
+      assert(syntaxErrorRE.test(stderr), 'stderr incorrect');
 
-    assert.strictEqual(c.status, 1, `code == ${c.status}`);
+      // stderr should include the filename
+      assert(stderr.startsWith(file), "stderr doesn't start with the filename");
+    }));
   });
 });
 
@@ -72,14 +78,15 @@ const notFoundRE = /^Error: Cannot find module/m;
   // loop each possible option, `-c` or `--check`
   syntaxArgs.forEach(function(args) {
     const _args = args.concat(file);
-    const c = spawnSync(node, _args, {encoding: 'utf8'});
+    const cmd = [node, ..._args].join(' ');
+    exec(cmd, common.mustCall((err, stdout, stderr) => {
+      // no stdout should be produced
+      assert.strictEqual(stdout, '', 'stdout produced');
 
-    // no stdout should be produced
-    assert.strictEqual(c.stdout, '', 'stdout produced');
+      // stderr should have a module not found error message
+      assert(notFoundRE.test(stderr), 'stderr incorrect');
 
-    // stderr should have a module not found error message
-    assert(notFoundRE.test(c.stderr), 'stderr incorrect');
-
-    assert.strictEqual(c.status, 1, `code == ${c.status}`);
+      assert.strictEqual(err.code, 1, `code === ${err.code}`);
+    }));
   });
 });