test: refactor test-cli-eval.js

* assert unused vars in test-cli-eval.js
* assert in more idiomatic way test-cli-eval
* rename status to err in test-cli-eval.js

PR-URL: nodejs/node#10759
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-cli-eval.js

@@ -19,13 +19,15 @@ const filename = __filename.replace(/\\/g, '/');
 // assert that nothing is written to stdout
 child.exec(nodejs + ' --eval 42',
            function(err, stdout, stderr) {
+             assert.ifError(err);
              assert.strictEqual(stdout, '');
              assert.strictEqual(stderr, '');
            });
 
 // assert that "42\n" is written to stderr
 child.exec(nodejs + ' --eval "console.error(42)"',
            function(err, stdout, stderr) {
+             assert.ifError(err);
              assert.strictEqual(stdout, '');
              assert.strictEqual(stderr, '42\n');
            });
@@ -36,66 +38,81 @@ child.exec(nodejs + ' --eval "console.error(42)"',
 
   child.exec(cmd + '42',
              function(err, stdout, stderr) {
+               assert.ifError(err);
                assert.strictEqual(stdout, '42\n');
                assert.strictEqual(stderr, '');
              });
 
   child.exec(cmd + "'[]'", common.mustCall(
       function(err, stdout, stderr) {
+        assert.ifError(err);
         assert.strictEqual(stdout, '[]\n');
         assert.strictEqual(stderr, '');
       }));
 });
 
 // assert that module loading works
 child.exec(nodejs + ' --eval "require(\'' + filename + '\')"',
-           function(status, stdout, stderr) {
-             assert.strictEqual(status.code, 42);
+           function(err, stdout, stderr) {
+             assert.strictEqual(err.code, 42);
+             assert.strictEqual(
+               stdout, 'Loaded as a module, exiting with status code 42.\n');
+             assert.strictEqual(stderr, '');
            });
 
 // Check that builtin modules are pre-defined.
 child.exec(nodejs + ' --print "os.platform()"',
-           function(status, stdout, stderr) {
+           function(err, stdout, stderr) {
+             assert.ifError(err);
              assert.strictEqual(stderr, '');
              assert.strictEqual(stdout.trim(), require('os').platform());
            });
 
 // module path resolve bug, regression test
 child.exec(nodejs + ' --eval "require(\'./test/parallel/test-cli-eval.js\')"',
-           function(status, stdout, stderr) {
-             assert.strictEqual(status.code, 42);
+           function(err, stdout, stderr) {
+             assert.strictEqual(err.code, 42);
+             assert.strictEqual(
+               stdout, 'Loaded as a module, exiting with status code 42.\n');
+             assert.strictEqual(stderr, '');
            });
 
 // Missing argument should not crash
-child.exec(nodejs + ' -e', common.mustCall(function(status, stdout, stderr) {
-  assert.notStrictEqual(status, null);
-  assert.strictEqual(status.code, 9);
+child.exec(nodejs + ' -e', common.mustCall(function(err, stdout, stderr) {
+  assert.strictEqual(err.code, 9);
+  assert.strictEqual(stdout, '');
+  assert(stderr.match(/node: -e requires an argument\n/));
 }));
 
 // empty program should do nothing
-child.exec(nodejs + ' -e ""', function(status, stdout, stderr) {
+child.exec(nodejs + ' -e ""', function(err, stdout, stderr) {
+  assert.ifError(err);
   assert.strictEqual(stdout, '');
   assert.strictEqual(stderr, '');
 });
 
 // "\\-42" should be interpreted as an escaped expression, not a switch
 child.exec(nodejs + ' -p "\\-42"',
            function(err, stdout, stderr) {
+             assert.ifError(err);
              assert.strictEqual(stdout, '-42\n');
              assert.strictEqual(stderr, '');
            });
 
 child.exec(nodejs + ' --use-strict -p process.execArgv',
-           function(status, stdout, stderr) {
+           function(err, stdout, stderr) {
+             assert.ifError(err);
              assert.strictEqual(
                stdout, "[ '--use-strict', '-p', 'process.execArgv' ]\n"
              );
+             assert.strictEqual(stderr, '');
            });
 
 // Regression test for https://github.com/nodejs/node/issues/3574
 const emptyFile = path.join(common.fixturesDir, 'empty.js');
 child.exec(nodejs + ` -e 'require("child_process").fork("${emptyFile}")'`,
-           function(status, stdout, stderr) {
+           function(err, stdout, stderr) {
+             assert.ifError(err);
              assert.strictEqual(stdout, '');
              assert.strictEqual(stderr, '');
            });