test: improve coverage of the util module

Add tests for untested branches and statements.
Change assert.equal to assert.strictEqual for consistency.

PR-URL: https://github.com/nodejs/node/pull/8633
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>

3 files changed, 126 insertions, 42 deletions

diff --git a/test/parallel/test-util-format.js b/test/parallel/test-util-format.js
index b8977e57b5..71265e4b6a 100644
--- a/test/parallel/test-util-format.js
+++ b/test/parallel/test-util-format.js
@@ -4,61 +4,70 @@ const assert = require('assert');
 const util = require('util');
 const symbol = Symbol('foo');
 
-assert.equal(util.format(), '');
-assert.equal(util.format(''), '');
-assert.equal(util.format([]), '[]');
-assert.equal(util.format([0]), '[ 0 ]');
-assert.equal(util.format({}), '{}');
-assert.equal(util.format({foo: 42}), '{ foo: 42 }');
-assert.equal(util.format(null), 'null');
-assert.equal(util.format(true), 'true');
-assert.equal(util.format(false), 'false');
-assert.equal(util.format('test'), 'test');
+assert.strictEqual(util.format(), '');
+assert.strictEqual(util.format(''), '');
+assert.strictEqual(util.format([]), '[]');
+assert.strictEqual(util.format([0]), '[ 0 ]');
+assert.strictEqual(util.format({}), '{}');
+assert.strictEqual(util.format({foo: 42}), '{ foo: 42 }');
+assert.strictEqual(util.format(null), 'null');
+assert.strictEqual(util.format(true), 'true');
+assert.strictEqual(util.format(false), 'false');
+assert.strictEqual(util.format('test'), 'test');
 
 // CHECKME this is for console.log() compatibility - but is it *right*?
-assert.equal(util.format('foo', 'bar', 'baz'), 'foo bar baz');
+assert.strictEqual(util.format('foo', 'bar', 'baz'), 'foo bar baz');
 
 // ES6 Symbol handling
-assert.equal(util.format(symbol), 'Symbol(foo)');
-assert.equal(util.format('foo', symbol), 'foo Symbol(foo)');
-assert.equal(util.format('%s', symbol), 'Symbol(foo)');
-assert.equal(util.format('%j', symbol), 'undefined');
+assert.strictEqual(util.format(symbol), 'Symbol(foo)');
+assert.strictEqual(util.format('foo', symbol), 'foo Symbol(foo)');
+assert.strictEqual(util.format('%s', symbol), 'Symbol(foo)');
+assert.strictEqual(util.format('%j', symbol), 'undefined');
 assert.throws(function() {
   util.format('%d', symbol);
 }, TypeError);
 
-assert.equal(util.format('%d', 42.0), '42');
-assert.equal(util.format('%d', 42), '42');
-assert.equal(util.format('%s', 42), '42');
-assert.equal(util.format('%j', 42), '42');
+assert.strictEqual(util.format('%d', 42.0), '42');
+assert.strictEqual(util.format('%d', 42), '42');
+assert.strictEqual(util.format('%s', 42), '42');
+assert.strictEqual(util.format('%j', 42), '42');
 
-assert.equal(util.format('%d', '42.0'), '42');
-assert.equal(util.format('%d', '42'), '42');
-assert.equal(util.format('%s', '42'), '42');
-assert.equal(util.format('%j', '42'), '"42"');
+assert.strictEqual(util.format('%d', '42.0'), '42');
+assert.strictEqual(util.format('%d', '42'), '42');
+assert.strictEqual(util.format('%s', '42'), '42');
+assert.strictEqual(util.format('%j', '42'), '"42"');
 
-assert.equal(util.format('%%s%s', 'foo'), '%sfoo');
+assert.strictEqual(util.format('%%s%s', 'foo'), '%sfoo');
 
-assert.equal(util.format('%s'), '%s');
-assert.equal(util.format('%s', undefined), 'undefined');
-assert.equal(util.format('%s', 'foo'), 'foo');
-assert.equal(util.format('%s:%s'), '%s:%s');
-assert.equal(util.format('%s:%s', undefined), 'undefined:%s');
-assert.equal(util.format('%s:%s', 'foo'), 'foo:%s');
-assert.equal(util.format('%s:%s', 'foo', 'bar'), 'foo:bar');
-assert.equal(util.format('%s:%s', 'foo', 'bar', 'baz'), 'foo:bar baz');
-assert.equal(util.format('%%%s%%', 'hi'), '%hi%');
-assert.equal(util.format('%%%s%%%%', 'hi'), '%hi%%');
+assert.strictEqual(util.format('%s'), '%s');
+assert.strictEqual(util.format('%s', undefined), 'undefined');
+assert.strictEqual(util.format('%s', 'foo'), 'foo');
+assert.strictEqual(util.format('%s:%s'), '%s:%s');
+assert.strictEqual(util.format('%s:%s', undefined), 'undefined:%s');
+assert.strictEqual(util.format('%s:%s', 'foo'), 'foo:%s');
+assert.strictEqual(util.format('%s:%s', 'foo', 'bar'), 'foo:bar');
+assert.strictEqual(util.format('%s:%s', 'foo', 'bar', 'baz'), 'foo:bar baz');
+assert.strictEqual(util.format('%%%s%%', 'hi'), '%hi%');
+assert.strictEqual(util.format('%%%s%%%%', 'hi'), '%hi%%');
+assert.strictEqual(util.format('%sbc%%def', 'a'), 'abc%def');
+
+assert.strictEqual(util.format('%d:%d', 12, 30), '12:30');
+assert.strictEqual(util.format('%d:%d', 12), '12:%d');
+assert.strictEqual(util.format('%d:%d'), '%d:%d');
+
+assert.strictEqual(util.format('o: %j, a: %j', {}, []), 'o: {}, a: []');
+assert.strictEqual(util.format('o: %j, a: %j', {}), 'o: {}, a: %j');
+assert.strictEqual(util.format('o: %j, a: %j'), 'o: %j, a: %j');
 
 {
   const o = {};
   o.o = o;
-  assert.equal(util.format('%j', o), '[Circular]');
+  assert.strictEqual(util.format('%j', o), '[Circular]');
 }
 
 // Errors
 const err = new Error('foo');
-assert.equal(util.format(err), err.stack);
+assert.strictEqual(util.format(err), err.stack);
 function CustomError(msg) {
   Error.call(this);
   Object.defineProperty(this, 'message',
@@ -69,7 +78,7 @@ function CustomError(msg) {
 }
 util.inherits(CustomError, Error);
 const customError = new CustomError('bar');
-assert.equal(util.format(customError), customError.stack);
+assert.strictEqual(util.format(customError), customError.stack);
 // Doesn't capture stack trace
 function BadCustomError(msg) {
   Error.call(this);
@@ -79,4 +88,5 @@ function BadCustomError(msg) {
                         { value: 'BadCustomError', enumerable: false });
 }
 util.inherits(BadCustomError, Error);
-assert.equal(util.format(new BadCustomError('foo')), '[BadCustomError: foo]');
+assert.strictEqual(util.format(new BadCustomError('foo')),
+                   '[BadCustomError: foo]');
diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index 3becf5b318..b2d23d3255 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -43,6 +43,12 @@ assert.strictEqual(util.inspect(Object.create({},
   '{ visible: 1 }'
 );
 
+{
+  const regexp = /regexp/;
+  regexp.aprop = 42;
+  assert.strictEqual(util.inspect({a: regexp}, false, 0), '{ a: /regexp/ }');
+}
+
 assert(/Object/.test(
   util.inspect({a: {a: {a: {a: {}}}}}, undefined, undefined, true)
 ));
@@ -245,6 +251,11 @@ value = function() {};
 value.aprop = 42;
 assert.strictEqual(util.inspect(value), '{ [Function: value] aprop: 42 }');
 
+// Anonymous function with properties
+value = (() => function() {})();
+value.aprop = 42;
+assert.strictEqual(util.inspect(value), '{ [Function] aprop: 42 }');
+
 // Regular expressions with properties
 value = /123/ig;
 value.aprop = 42;
@@ -901,4 +912,12 @@ checkAlignment(new Map(big_array.map(function(y) { return [y, null]; })));
     JSON.stringify(util.inspect.defaultOptions),
     JSON.stringify(oldOptions)
   );
+
+  assert.throws(() => {
+    util.inspect.defaultOptions = null;
+  }, /"options" must be an object/);
+
+  assert.throws(() => {
+    util.inspect.defaultOptions = 'bad';
+  }, /"options" must be an object/);
 }
diff --git a/test/parallel/test-util.js b/test/parallel/test-util.js
index 023583ca4c..6072f9ae9a 100644
--- a/test/parallel/test-util.js
+++ b/test/parallel/test-util.js
@@ -1,8 +1,8 @@
 'use strict';
-require('../common');
-var assert = require('assert');
-var util = require('util');
-var context = require('vm').runInNewContext;
+const common = require('../common');
+const assert = require('assert');
+const util = require('util');
+const context = require('vm').runInNewContext;
 
 // isArray
 assert.equal(true, util.isArray([]));
@@ -86,3 +86,58 @@ assert.deepStrictEqual(util._extend({a: 1}, true), {a: 1});
 assert.deepStrictEqual(util._extend({a: 1}, false), {a: 1});
 assert.deepStrictEqual(util._extend({a: 1}, {b: 2}), {a: 1, b: 2});
 assert.deepStrictEqual(util._extend({a: 1, b: 2}, {b: 3}), {a: 1, b: 3});
+
+// deprecated
+assert.strictEqual(util.isBoolean(true), true);
+assert.strictEqual(util.isBoolean(false), true);
+assert.strictEqual(util.isBoolean('string'), false);
+
+assert.strictEqual(util.isNull(null), true);
+assert.strictEqual(util.isNull(), false);
+assert.strictEqual(util.isNull('string'), false);
+
+assert.strictEqual(util.isUndefined(), true);
+assert.strictEqual(util.isUndefined(null), false);
+assert.strictEqual(util.isUndefined('string'), false);
+
+assert.strictEqual(util.isNullOrUndefined(null), true);
+assert.strictEqual(util.isNullOrUndefined(), true);
+assert.strictEqual(util.isNullOrUndefined('string'), false);
+
+assert.strictEqual(util.isNumber(42), true);
+assert.strictEqual(util.isNumber(), false);
+assert.strictEqual(util.isNumber('string'), false);
+
+assert.strictEqual(util.isString('string'), true);
+assert.strictEqual(util.isString(), false);
+assert.strictEqual(util.isString(42), false);
+
+assert.strictEqual(util.isSymbol(Symbol()), true);
+assert.strictEqual(util.isSymbol(), false);
+assert.strictEqual(util.isSymbol('string'), false);
+
+assert.strictEqual(util.isFunction(() => {}), true);
+assert.strictEqual(util.isFunction(function() {}), true);
+assert.strictEqual(util.isFunction(), false);
+assert.strictEqual(util.isFunction('string'), false);
+
+const expected = [
+  'util.print is deprecated. Use console.log instead.',
+  'util.puts is deprecated. Use console.log instead.',
+  'util.debug is deprecated. Use console.error instead.',
+  'util.error is deprecated. Use console.error instead.'
+];
+
+process.on('warning', common.mustCall((warning) => {
+  assert.strictEqual(warning.name, 'DeprecationWarning');
+  assert.notStrictEqual(expected.indexOf(warning.message), -1,
+                        `unexpected error message: "${warning.message}"`);
+  // Remove a warning message after it is seen so that we guarantee that we get
+  // each message only once.
+  expected.splice(expected.indexOf(warning.message), 1);
+}, expected.length));
+
+util.print('test');
+util.puts('test');
+util.debug('test');
+util.error('test');