Cleaning up the typeof calls - working on refactoring the retrieveHeading function now

Author: mrodrig

lib/csv-2-json.js

@@ -34,7 +34,7 @@ var addNestedKey = function (key, value, doc) {
 
 // Helper function to check if the given key already exists in the given document
 var keyExists = function (key, doc) {
-    return (typeof doc[key] !== 'undefined'); // If the key doesn't exist, then the type is 'undefined'
+    return (!_.isUndefined(doc[key])); // If the key doesn't exist, then the type is 'undefined'
 };
 
 var isArrayRepresentation = function (value) {
@@ -96,7 +96,7 @@ module.exports = {
         if (!opts) { callback(new Error('Options were not passed and are required.')); return null; } // Shouldn't happen, but just in case
         else { options = opts; } // Options were passed, set the global options value
         if (!data) { callback(new Error('Cannot call csv2json on ' + data + '.')); return null; } // If we don't receive data, report an error
-        if (typeof data !== 'string') { // The data is not a string
+        if (!_.isString(data)) { // The data is not a string
             callback(new Error("CSV is not a string.")); // Report an error back to the caller
         }
         var lines = data.split(options.EOL); // Split the CSV into lines using the specified EOL option

lib/json-2-csv.js

@@ -12,7 +12,7 @@ var retrieveSubHeading = function (heading, data) {
     _.each(subKeys, function (subKey, indx) {
         // If the given heading is empty, then we set the heading to be the subKey, otherwise set it as a nested heading w/ a dot
         newKey = heading === '' ? subKey : heading + '.' + subKey;
-        if (typeof data[subKey] === 'object' && data[subKey] !== null && typeof data[subKey].length === 'undefined' && _.keys(data[subKey]).length > 0) { // If we have another nested document
+        if (_.isObject(data[subKey]) && !_.isNull(data[subKey]) && _.isUndefined(data[subKey].length) && _.keys(data[subKey]).length > 0) { // If we have another nested document
             subKeys[indx] = retrieveSubHeading(newKey, data[subKey]); // Recur on the subdocument to retrieve the full key name
         } else {
             subKeys[indx] = (options.DELIMITER.WRAP || '') + (newKey || '') + (options.DELIMITER.WRAP || ''); // Set the key name since we don't have a sub document
@@ -22,21 +22,19 @@ var retrieveSubHeading = function (heading, data) {
 };
 
 // Retrieve the headings for all documents and return it.  This checks that all documents have the same schema.
-var retrieveHeading = function (data) {
-    return function (cb) { // Returns a function that takes a callback - the function is passed to async.parallel
-        var keys = _.keys(data); // Retrieve the current data keys
-        _.each(keys, function (key, indx) { // for each key
-            if (typeof data[key] === 'object') {
-                // if the data at the key is a document, then we retrieve the subHeading starting with an empty string heading and the doc
-                keys[indx] = retrieveSubHeading('', data[key]);
-            }
-        });
-        // Retrieve the unique array of headings (keys)
-        keys = _.uniq(keys);
-        // If we have more than 1 unique list, then not all docs have the same schema - report an error
-        if (keys.length > 1) { throw new Error('Not all documents have the same schema.', keys); }
-        return cb(null, _.flatten(keys).join(options.DELIMITER.FIELD)); // Return headings back
-    };
+var retrieveHeading = function (data, cb) {
+    var keys = _.keys(data); // Retrieve the current data keys
+    _.each(keys, function (key, indx) { // for each key
+        if (_.isObject(data[key])) {
+            // if the data at the key is a document, then we retrieve the subHeading starting with an empty string heading and the doc
+            keys[indx] = retrieveSubHeading('', data[key]);
+        }
+    });
+    // Retrieve the unique array of headings (keys)
+    keys = _.uniq(keys);
+    // If we have more than 1 unique list, then not all docs have the same schema - report an error
+    if (keys.length > 1) { throw new Error('Not all documents have the same schema.', keys); }
+    return cb(null, _.flatten(keys).join(options.DELIMITER.FIELD)); // Return headings back
 };
 
 // Convert the given data with the given keys
@@ -62,11 +60,9 @@ var convertData = function (data, keys) {
 };
 
 // Generate the CSV representing the given data.
-var generateCsv = function (data) {
-    return function (cb) { // Returns a function that takes a callback - the function is passed to async.parallel
-        // Reduce each JSON document in data to a CSV string and append it to the CSV accumulator
-        return cb(null, _.reduce(data, function (csv, doc) { return csv += convertData(doc, _.keys(doc)) + options.EOL; }, ''));
-    };
+var generateCsv = function (data, cb) {
+    // Reduce each JSON document in data to a CSV string and append it to the CSV accumulator
+    return cb(null, _.reduce(data, function (csv, doc) { return csv += convertData(doc, _.keys(doc)) + options.EOL; }, ''));
 };
 
 module.exports = {
@@ -78,13 +74,14 @@ module.exports = {
         if (!opts) { callback(new Error('Options were not passed and are required.')); return null; } // Shouldn't happen, but just in case
         else { options = opts; } // Options were passed, set the global options value
         if (!data) { callback(new Error('Cannot call json2csv on ' + data + '.')); return null; } // If we don't receive data, report an error
-        if (typeof data !== 'object') { // If the data was not a single document or an array of documents
+        if (!_.isObject(data)) { // If the data was not a single document or an array of documents
             return cb(new Error('Data provided was not an array of documents.'));  // Report the error back to the caller
-        } else if (typeof data === 'object' && !data.length) { // Single document, not an array
+        } else if (_.isObject(data) && !data.length) { // Single document, not an array
             data = [data]; // Convert to an array of the given document
         }
+
         // Retrieve the heading and the CSV asynchronously in parallel
-        async.parallel([retrieveHeading(data), generateCsv(data)], function (err, res) {
+        async.parallel([_.partial(retrieveHeading, data), _.partial(generateCsv, data)], function (err, res) {
             if (!err) {
                 // Data received with no errors, join the two responses with an end of line delimiter to setup heading and CSV body
                 return callback(null, res.join(options.EOL));