test: refactor test-repl-tab-complete

The original test uses a variable to explicitly count how many
times the callback is invoked. This patch uses common.mustCall()
to track if the callback is called or not. This makes the test
more robust, as we don't explicitly hardcode the number of times
to be called.

PR-URL: https://github.com/nodejs/io.js/pull/2122
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

test/parallel/test-repl-tab-complete.js

@@ -4,15 +4,17 @@ var assert = require('assert');
 var util = require('util');
 var repl = require('repl');
 var referenceErrors = 0;
-var completionCount = 0;
+var expectedReferenceErrors = 0;
 
-function doNotCall() {
+function getDoNotCallFunction() {
+  expectedReferenceErrors += 1;
+  return function() {
     assert(false);
+  };
 }
 
 process.on('exit', function() {
-  assert.strictEqual(referenceErrors, 6);
+  assert.strictEqual(referenceErrors, expectedReferenceErrors);
-  assert.strictEqual(completionCount, 12);
 });
 
 // A stream to push an array into a REPL
@@ -51,19 +53,17 @@ putIn.run([
   'var inner = {',
   'one:1'
 ]);
-testMe.complete('inner.o', doNotCall);
+testMe.complete('inner.o', getDoNotCallFunction());
 
-testMe.complete('console.lo', function(error, data) {
+testMe.complete('console.lo', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, [['console.log'], 'console.lo']);
-});
+}));
 
 // Tab Complete will return globaly scoped variables
 putIn.run(['};']);
-testMe.complete('inner.o', function(error, data) {
+testMe.complete('inner.o', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, works);
-});
+}));
 
 putIn.run(['.clear']);
 
@@ -73,7 +73,7 @@ putIn.run([
   '?',
   '{one: 1} : '
 ]);
-testMe.complete('inner.o', doNotCall);
+testMe.complete('inner.o', getDoNotCallFunction());
 
 putIn.run(['.clear']);
 
@@ -82,15 +82,14 @@ putIn.run([
   'var top = function() {',
   'var inner = {one:1};'
 ]);
-testMe.complete('inner.o', function(error, data) {
+testMe.complete('inner.o', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, works);
-});
+}));
 
 // When you close the function scope tab complete will not return the
 // locally scoped variable
 putIn.run(['};']);
-testMe.complete('inner.o', doNotCall);
+testMe.complete('inner.o', getDoNotCallFunction());
 
 putIn.run(['.clear']);
 
@@ -101,10 +100,9 @@ putIn.run([
   ' one:1',
   '};'
 ]);
-testMe.complete('inner.o', function(error, data) {
+testMe.complete('inner.o', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, works);
-});
+}));
 
 putIn.run(['.clear']);
 
@@ -116,10 +114,9 @@ putIn.run([
   ' one:1',
   '};'
 ]);
-testMe.complete('inner.o', function(error, data) {
+testMe.complete('inner.o', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, works);
-});
+}));
 
 putIn.run(['.clear']);
 
@@ -132,10 +129,9 @@ putIn.run([
   ' one:1',
   '};'
 ]);
-testMe.complete('inner.o', function(error, data) {
+testMe.complete('inner.o', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, works);
-});
+}));
 
 putIn.run(['.clear']);
 
@@ -148,7 +144,7 @@ putIn.run([
   ' one:1',
   '};'
 ]);
-testMe.complete('inner.o', doNotCall);
+testMe.complete('inner.o', getDoNotCallFunction());
 
 putIn.run(['.clear']);
 
@@ -161,7 +157,7 @@ putIn.run([
   ' one:1',
   '};'
 ]);
-testMe.complete('inner.o', doNotCall);
+testMe.complete('inner.o', getDoNotCallFunction());
 
 putIn.run(['.clear']);
 
@@ -175,7 +171,7 @@ putIn.run([
   ' one:1',
   '};'
 ]);
-testMe.complete('inner.o', doNotCall);
+testMe.complete('inner.o', getDoNotCallFunction());
 
 putIn.run(['.clear']);
 
@@ -183,10 +179,9 @@ putIn.run(['.clear']);
 putIn.run([
   'var str = "test";'
 ]);
-testMe.complete('str.len', function(error, data) {
+testMe.complete('str.len', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, [['str.length'], 'str.len']);
-});
+}));
 
 putIn.run(['.clear']);
 
@@ -195,32 +190,28 @@ var spaceTimeout = setTimeout(function() {
   throw new Error('timeout');
 }, 1000);
 
-testMe.complete(' ', function(error, data) {
+testMe.complete(' ', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, [[], undefined]);
   clearTimeout(spaceTimeout);
-});
+}));
 
 // tab completion should pick up the global "toString" object, and
 // any other properties up the "global" object's prototype chain
-testMe.complete('toSt', function(error, data) {
+testMe.complete('toSt', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, [['toString'], 'toSt']);
-});
+}));
 
 // Tab complete provides built in libs for require()
 putIn.run(['.clear']);
 
-testMe.complete('require(\'', function(error, data) {
+testMe.complete('require(\'', common.mustCall(function(error, data) {
-  completionCount++;
   assert.strictEqual(error, null);
   repl._builtinLibs.forEach(function(lib) {
     assert.notStrictEqual(data[0].indexOf(lib), -1, lib + ' not found');
   });
-});
+}));
 
-testMe.complete('require(\'n', function(error, data) {
+testMe.complete('require(\'n', common.mustCall(function(error, data) {
-  completionCount++;
   assert.strictEqual(error, null);
   assert.strictEqual(data.length, 2);
   assert.strictEqual(data[1], 'n');
@@ -230,7 +221,7 @@ testMe.complete('require(\'n', function(error, data) {
     if (completion)
       assert(/^n/.test(completion));
   });
-});
+}));
 
 // Make sure tab completion works on context properties
 putIn.run(['.clear']);
@@ -238,7 +229,6 @@ putIn.run(['.clear']);
 putIn.run([
   'var custom = "test";'
 ]);
-testMe.complete('cus', function(error, data) {
+testMe.complete('cus', common.mustCall(function(error, data) {
-  completionCount++;
   assert.deepEqual(data, [['custom'], 'cus']);
-});
+}));