Search tree node via closure in Google Apps Script - unit-testing

Question

General problem I'm trying to solve
I'm trying to implement a search tree in Google Apps Script, sorted by pkgName attribute, with the end purpose of comparing imported metadata on a software project against a Sheet containing similar data.
To keep the namespace of the constructor function from being polluted with "private" properties, I used closures.
Implementation
The implementation I have thus far is thus:
SheetDataNode.gs
/**
* Constructor for a SheetDataNode. Takes one, three, or four arguments.
* #param { { package : string, files : { complexity : number, name : string, testingStatus : string }[], rowNumber : number } | string } line data or package name
* #param { string } filename : the files contained in package
* #param { number } complexity : the total number of branches in the file
* #param { number } rowNumber : the row number as this appears in the spreadsheet it is being created from
* #param { string } [ testingStatus ] : the status on the testing of this file. Should be one of the following: NOT_TESTED, FULLY_TESTED, IN_PROGRESS, or PARTIAL
* #returns { SheetDataNode }
* #deprecated This function is not working right now
**/
function SheetDataNode(data, filename, complexity, rowNumber, testingStatus) {
var _pkgName = '';
var _leftChild = null;
var _rightChild = null;
var _beenFound = false;
var _rowNumber = rowNumber;
var _files = [];
// if there's only one argument, it better be an object, having the required fields
if (arguments.length === 1) {
// it should have package field
if ((data.package === undefined) || (data.package !== data.package.toString())) {
throw ReferenceError('only one argument was specified, but it is not an object that contains package');
}
// it should have files field
if ((data.files === undefined) || (!Array.isArray(data.files))) {
throw ReferenceError('Called from the one-arg constructor, so files should be Array');
}
// that files field should itself be an object with the following fields: complexity and name
for (var idx in data.files) {
if (data.files[idx].complexity !== parseInt(data.files[idx].complexity)) {
throw TypeError("complexity should be an integer");
}
if (data.files[idx].name !== data.files[idx].name.toString()) {
throw TypeError("name of file should be a string");
}
}
// sort the array of files
data.files.sort(fileSorter)
// call the initialization function
return SheetDataNode._init(data.package, data.files, parseInt(data.rowNumber));
}
// performing argument checking
if (filename !== filename.toString()) throw TypeError("filename is supposed to be a String")
if ((complexity !== undefined) && (complexity !== parseInt(complexity))) {
throw TypeError("complexity must be a number, or undefined")
}
// call the initialization function, constructing a single file object
return SheetDataNode._init(data.toString(), [{
complexity : complexity,
name: filename,
testingStatus : testingStatus
}])
}
// Helper private function that performs initialization
SheetDataNode._init = function(package, files, rowNumber) {
// bring in the variables
var _pkgName = package;
var _files = files;
var _leftChild = null;
var _rightChild = null;
var _beenFound = false;
var _rowNumber = rowNumber;
// providing a function to add file
_addFile = function(file) {
for (var f in _files) {
if (file.name < _files[f].name) {
_files.splice(f, 0, file)
return
}
}
_files.push(file)
}
return {
getRowNumber : function() { return _rowNumber; },
getPackageName : function () { return _pkgName; },
getFiles: function() { return _files; },
addFile : _addFile,
addFiles : function(files) {
if (!Array.isArray(files)) throw TypeError("files should be an Array")
for (var idx in files) {
_addFile(files[idx])
}
},
getLeftChild : function() { return _leftChild; },
setLeftChild : function(node) {
_leftChild = node;
},
getRightChild : function() { return _rightChild; },
setRightChild : function(node) {
_rightChild = node;
},
insertNode : function(node) {
// set the current node as the head node
var currentNode = this;
// while we are on a non-null node
while (currentNode) {
// if the package of node is the same as that of currentNode
if (currentNode.getPackageName() === node.getPackageName()) {
// simply add the files of node to currentNode._files
currentNode.addFiles(node.getFiles())
return
}
// if the package of node "comes before" that of currentNode, move to the left
if (currentNode.getPackageName() > node.getPackageName()) {
// if the left child of node is defined, that becomes the current node
if (currentNode.getLeftChild()) currentNode = currentNode.getLeftChild()
// else construct it, and we're done
else {
currentNode.setLeftChild(node)
return
}
}
// if the package of node "comes after" that of currentNode, move to the right
if (currentNode.getPackageName() < node.getPackageName()) {
// if the right child of node is defined, that becomes the current node
if (currentNode.getRightChild()) currentNode = currentNode.getRightChild()
// else construct it, and we're done
else {
currentNode.setRightChild(node)
return
}
}
throw Error("Whoa, some infinite looping was about to happen!")
}
}
}
}
UtilityFunctions.gs
/**
* Sorts file objects by their name property, alphabetically
* #param { { name : string } } lvalue
* #param { { name : string } } rvalue
* #returns { boolean } the lexical comparison of lvalue.name,rvalue.name
**/
function fileSorter(lvalue, rvalue) {
if (lvalue.name > rvalue.name) return 1;
return (lvalue.name < rvalue.name) ? -1 : 0;
}
Problem
I'm unit-testing the code, with the failing test case consisting of the following steps :
construct a SheetDataNode node
construct another SheetDataNode otherNode with the same package name as the first, but different filename
insert otherNode into node
expectation: it now has two files
actual: it only has one: the original.
expectation: neither left nor right child nodes were set by this operation
actual : neither left nor right child nodes were set by this operation
The code to do the above looks like this:
QUnit.test("inserting a node having the same package as the node it is assigned to",
function() {
// create the base node
var node = SheetDataNode("example", "main.go", 3, 1)
// insert an other node, with identical package name
var otherNode = SheetDataNode(node.getPackageName(), "logUtility.go", 12, 3)
node.insertNode(otherNode)
// node should contain two files, and neither a left child nor a right child
deepEqual(node.getFiles().map(function(val) {
return val.name
}),
["logUtility.go", "main.go"],
"node contains the right file names")
equal(node.getFiles().length, 2, "A package got added to the node")
ok(!node.getLeftChild(), "leftChild still unset")
ok(!node.getRightChild(), "rightChild still unset")
})
Here is screenshot of the failing assertions:
Remember that the method under test is like this:
insertNode : function(node) {
// set the current node as the head node
var currentNode = this;
// while we are on a non-null node
while (currentNode) {
// if the package of node is the same as that of currentNode
if (currentNode.getPackageName() === node.getPackageName()) {
// simply add the files of node to currentNode._files
currentNode.addFiles(node.getFiles())
return
}
// if the package of node "comes before" that of currentNode, move to the left
if (currentNode.getPackageName() > node.getPackageName()) {
// if the left child of node is defined, that becomes the current node
if (currentNode.getLeftChild()) currentNode = currentNode.getLeftChild()
// else construct it, and we're done
else {
currentNode.setLeftChild(node)
return
}
}
// if the package of node "comes after" that of currentNode, move to the right
if (currentNode.getPackageName() < node.getPackageName()) {
// if the right child of node is defined, that becomes the current node
if (currentNode.getRightChild()) currentNode = currentNode.getRightChild()
// else construct it, and we're done
else {
currentNode.setRightChild(node)
return
}
}
throw Error("Whoa, some infinite looping was about to happen!")
}
The test against the method addFiles, which has this code:
QUnit.test("testing method addFiles",
function() {
// create the base node
var node = SheetDataNode("example", "main.go", 3, 1)
// create an array of files to add
const filesToAdd = [{
name : 'aFile.go',
complexity : 10
}, {
name : 'anotherFile.go',
complexity : 10
}, {
name : 'yetAnotherFile.go',
complexity : 10
}]
// is node.getFiles() an array?!
ok(Array.isArray(node.getFiles()), "node.getFiles() is an array")
// add the files
node.addFiles(filesToAdd)
Logger.log(node.getFiles())
// node.getFiles() should be an Array
ok(Array.isArray(node.getFiles()), "node.getFiles() is still an array")
// node.getFiles should now contain filesToAdd
equal(node.getFiles().length, 1 + filesToAdd.length, "node.getFiles().length increased by the length of the files to add")
})
passes:
, as do the other tests against insertNode, meaning the problem might exist with how we try to reference currentNode in insertNode for array property modification. If so, I have no idea how else to reference, in Google Apps Script, the SheetDataNode to undergo state change

Answer 1

I was able to solve the problem, with inspiration from the MDN docs on closures, by changing the private function property declaration from :
_addFile = function(file) {
for (var f in _files) {
if (file.name < _files[f].name) {
_files.splice(f, 0, file)
return
}
}
_files.push(file)
}
to
function _addFile(file) {
for (var f in _files) {
if (file.name < _files[f].name) {
_files.splice(f, 0, file)
return
}
}
_files.push(file)
}
idk why this works, because I forgot the difference between declaring method like a function variable (what I was doing), and preceding the name of the method with function like it's any other function. I'll have to (re-)learn that...