Add logger module.

Author: wnmurphy

calculateFloatTurnover.js

@@ -6,7 +6,7 @@
   
   Example usage: node float GPRO 77930000 2017-01-04
 */
-const log = console.log;
+const log = require('./src/logger.js');
 const rp = require('request-promise');
 const config = require('./config.js')
 const parseRawData = require('./src/parseRawData.js');
@@ -18,7 +18,7 @@ const startDate = process.argv[4];
 const reverse = process.argv[5] === 'reverse' ? true : false;
 
 const fetchDataForOneStock = (ticker) => new Promise((resolve, reject) => {
-  log('Getting: ', '\x1b[34m', ticker, '\x1b[0m');
+  log(info, `Getting: \x1b[34m${ticker}\x1b[0m`);
   return rp({ // Request data for this stock.
     uri: 'https://www.alphavantage.co/query',
     json: true,
@@ -106,7 +106,9 @@ fetchDataForOneStock(ticker)
       return [day.date, day.v];
     });
     return volumeByDate;
-  }).then(volumeByDate => {
+  })
+  .then(volumeByDate => {
     const result = getFloatTurnovers(volumeByDate, totalFloat, startDate, reverse);
-    log(result);
-  }).catch(e => console.log(`Error: ${e}`));
+    log('info', result);
+  })
+  .catch(e => log('warn', e, e.stack));

config.js

@@ -1,3 +1,4 @@
 module.exports = {
-  API_KEY : "U9RKMXCNKJZOWNFR"
+  API_KEY : 'U9RKMXCNKJZOWNFR',
+  logLevels: ['info', 'warn', 'critical', 'debug']
 }

findOuterPivotsOnLowerVolume.js

@@ -35,7 +35,7 @@ const filterResults = require('./src/filterResults.js');
 const printToScreen = require('./src/printResults.js');
 const writeToCsv = require('./src/writeCSV.js');
 const throttle = createThrottle(1, 1900);
-const log = console.log;
+const log = require('./src/logger.js');
 const data = require('./src/stockData.js');
 
 // Date is passed in from command line in format 'YYYY-MM-DD'.
@@ -60,14 +60,14 @@ const filter = process.argv[2] ? [
       await throttle();
       return await fetchStock(ticker);
     } catch (err) {
-      log(err);
+      log('warn', err);
     }
   });
 
   Promise.all(tickerRequests)
     .then(() => {
-      log(`\n\x1b[31m Fetch complete. \x1b[0m`);
-      log('Retries: ', data.retries);
+      log('info', '\n\x1b[31m Fetch complete. \x1b[0m');
+      log('info', `Retries: ${data.retries}`);
     })
     .then(() => {
       if (data.retries.length) {
@@ -78,7 +78,7 @@ const filter = process.argv[2] ? [
       }
     })
     .then(() => {
-      log('\n\x1b[31m' + 'Retries complete.' + '\x1b[0m');
+      log('info', '\n\x1b[31m Retries complete.\x1b[0m');
 
       let results;
 
@@ -87,23 +87,23 @@ const filter = process.argv[2] ? [
       }
       else {
         results = data.allSignals;
-        log('\n\x1b[31m' + 'No search filter provided. All results: ' + '\x1b[0m' + '\n');
+        log('info', '\n\x1b[31m' + 'No search filter provided. All results: ' + '\x1b[0m' + '\n');
       }
 
       if (results.length) {
-        log('\n\x1b[31m' + 'Search Results:' + '\x1b[0m');
+        log('info', '\n\x1b[31m' + 'Search Results:' + '\x1b[0m');
         printToScreen(results);
         writeToCsv(results);
 
         if(every(results, allResultsShort) || every(results, allResultsLong)) {
-          log('\n\x1b[32m' + 'All results agree. This has been a reliable signal about next trading day for the market' + '\x1b[0m');
+          log('info', '\n\x1b[32m' + 'All results agree. This has been a reliable signal about next trading day for the market' + '\x1b[0m');
         }
       }
       else {
-        log('\n\x1b[31m' + 'No results.' + '\x1b[0m');
+        log('info', '\n\x1b[31m' + 'No results.' + '\x1b[0m');
       }
     })
-    .catch(e => log(e));
+    .catch(e => log('warn', e));
 })();
 
 

scrapeFloat.js

@@ -3,11 +3,11 @@ const createThrottle = require('./src/createThrottle.js')
 const throttle = createThrottle(1, 4000);
 const tickers = require('./stockList.js');
 const fs = require('fs');
-const log = console.log;
+const log = require('.logger.js');
 
 // Retreives financial data from Yahoo Finance, scrapes the float for a ticker, and returns it as a tuple.
 const scrapeFloat = (ticker) => new Promise((resolve, reject) => {
-  console.log(`Scraping float for ${ticker}...`);
+  log('info', `Scraping float for ${ticker}...`);
   return rp({ 
     uri: `https://finance.yahoo.com/quote/${ticker}/key-statistics/`,
     json: true,
@@ -16,7 +16,7 @@ const scrapeFloat = (ticker) => new Promise((resolve, reject) => {
     const searchTerm = 'floatShares":{"raw":';
     const floatIdx = response.indexOf(searchTerm);
     if (floatIdx < 0) {
-      log(`Search term ${searchTerm} not found in response.`)
+      log('info', `Search term ${searchTerm} not found in response.`)
     }
     const startIdx = floatIdx + searchTerm.length;
     const endIdx = startIdx + 20;
@@ -26,7 +26,7 @@ const scrapeFloat = (ticker) => new Promise((resolve, reject) => {
     resolve([ticker, parseInt(float)]);
   })
   .catch(err => { 
-    log(`error scraping float for ${ticker}: ${JSON.stringify(error)}`);
+    log('warn', `error scraping float for ${ticker}: ${JSON.stringify(error)}`);
   })
 }); 
 
@@ -41,10 +41,10 @@ const getAllFloats = (tickers) => {
       for (const floatEntry of results) {
         floatMap[floatEntry[0]] = floatEntry[1];
       }
-      log(`floatMap: ${JSON.stringify(floatMap)}`);
+      log('info', `floatMap: ${JSON.stringify(floatMap)}`);
       return floatMap;
     })
-    .catch(e => log(`Error: ${e}`));
+    .catch(e => log('warn', `Error getting all floats: ${e}`));
 };
 
 async function main() {
@@ -57,7 +57,7 @@ async function main() {
     const stringifiedData = JSON.stringify(fileObj);
     fs.writeFileSync('./floats.json', stringifiedData);
   } catch (e) {
-    console.log(e);
+    log('warn', e);
   }
 }
 

src/diskUtils.js

@@ -1,16 +1,17 @@
 const fs = require('fs');
 const folderPath = 'stockData';
 const daysBetween = require('./daysBetween.js');
+const log = require('./logger.js');
 
 
 /**
   Initializes the local stock data folder if it doesn't yet exist.
 */
-function initDataFolder() {
-  if (!fs.existsSync(folderPath)){
-    console.log(`${folderPath} folder doesn't exist. Creating...`);
-    fs.mkdirSync(folderPath, (err) => {
-      if (err) console.log(err);
+function initDataFolder(path) {
+  if (!fs.existsSync(path)) {
+    log('info', `${path} folder doesn't exist. Creating...`);
+    fs.mkdirSync(path, (err) => {
+      if (err) log('warn', err);
     });
   }
 }
@@ -24,7 +25,7 @@ function readStockDataFromDisk(ticker) {
   const filePath = `${folderPath}/${ticker}.json`;
   try {
     const data = fs.readFileSync(filePath, 'utf8');
-    console.log(`Local data found for ${ticker}.`);
+    log('info', `Local data found for ${ticker}.`);
     return JSON.parse(data);
   }
   catch (err) {
@@ -40,7 +41,7 @@ function readStockDataFromDisk(ticker) {
 */
 function writeStockDataToDisk(ticker, incomingData, existingData) {
 
-  initDataFolder();
+  initDataFolder(folderPath);
 
   const filePath = `${folderPath}/${ticker}.json`;
   const now = new Date();
@@ -53,13 +54,13 @@ function writeStockDataToDisk(ticker, incomingData, existingData) {
   // If we're creating the file for the first time.
   if (!fs.existsSync(filePath)) {
     try {
-      console.log(`${ticker} - ${filePath} doesn't exist. Creating...`);
+      log('info', `${ticker} - ${filePath} doesn't exist. Creating...`);
       const stringifiedData = JSON.stringify(writeObject);
       fs.writeFileSync(filePath, stringifiedData);
-      console.log(`${ticker} - Wrote data to disk.`);
+      log('info', `${ticker} - Wrote data to disk.`);
       return incomingData;
     } catch (err) {
-      console.log(`${ticker} - Error creating new file: `, err);
+      log('warn', `${ticker} - Error creating new file: `, err);
     }
   } 
   // Otherwise, we're appending data to existing file.
@@ -71,18 +72,18 @@ function writeStockDataToDisk(ticker, incomingData, existingData) {
       const sliceAfterIdx = incomingData.findIndex(day => day.date === lastDateRetrievedForExistingData);
       if (sliceAfterIdx > 0) {
         const newData = incomingData.slice(sliceAfterIdx + 1);
-        console.log(`${ticker} - Got ${newData.length} entries. Applying partial update.`);
+        log('info', `${ticker} - Got ${newData.length} entries. Applying partial update.`);
         writeObject.data = existingData.concat(newData);
       }
     }
     try {
       const stringifiedData = JSON.stringify(writeObject);
-      console.log(`File for ${ticker} exists. Updating...`);
+      log('info', `File for ${ticker} exists. Updating...`);
       fs.writeFileSync(filePath, stringifiedData);
-      console.log(`${ticker} - Updated data on disk.`);
+      log('info', `${ticker} - Updated data on disk.`);
       return writeObject.data;
     } catch (err) {
-      console.log(`${ticker} - Error updating existing data on disk: `, err);
+      log('warn', `${ticker} - Error updating existing data on disk: `, err);
     }    
   }
 }

src/fetchDataForOneStock.js

@@ -6,14 +6,14 @@ const buildHeatmap = require('./buildHeatMap');
 const findHits = require('./findHits.js');
 const buildSignals = require('./buildSignals.js');
 const daysBetween = require('./daysBetween.js');
-const log = console.log;
+const log = require('./logger.js');
 const data = require('./stockData.js');
 const diskUtils = require('./diskUtils');
 
 // Requests data for one stock ticker with a promise.
 const fetchDataForOneStock = (ticker) => new Promise((resolve, reject) => {
 
-  log('Getting: ', '\x1b[34m', ticker, '\x1b[0m');
+  log('info', `Getting: \x1b[34m'${ticker}\x1b[0m`);
   const queryString = {
     apikey: config.API_KEY,
     function: 'TIME_SERIES_DAILY',
@@ -34,11 +34,11 @@ const fetchDataForOneStock = (ticker) => new Promise((resolve, reject) => {
   } catch (e) {
     // If we have no local data for this ticker, retrieve complete history.
     if (e.code === 'ENOENT') {
-      log(`${ticker} - No local data.`);
+      log('info', `${ticker} - No local data.`);
       queryString.outputsize = 'full'; 
     }
     else {
-      log(`${ticker} - Error reading data from disk: `, e);
+      log('warn', `${ticker} - Error reading data from disk: ${e}`);
     }
   }
 
@@ -50,8 +50,8 @@ const fetchDataForOneStock = (ticker) => new Promise((resolve, reject) => {
     transform: parseRawData
   })
   .then(parsedData => {
-    log('Got: ', '\x1b[34m', ticker, '\x1b[0m');
-    console.log(`${ticker} - Retrieved ${parsedData.length} entries.`)
+    log('info', `Got: \x1b[34m${ticker}\x1b[0m`);
+    log('info', `${ticker} - Retrieved ${parsedData.length} entries.`)
     // Append to data stored locally.
     const localData = localFile ? localFile.data : null;
     parsedData = diskUtils.writeStockDataToDisk(ticker, parsedData, localData);
@@ -76,7 +76,7 @@ const fetchDataForOneStock = (ticker) => new Promise((resolve, reject) => {
   })
   .catch(err => { 
     // Tell user if something went wrong.
-    log('\n' + '\x1b[31m' + 'Ticker: ' + ticker + '\n' + 'Error: ' + '\x1b[0m' + '\n' + err);
+    log('warn', `\n\x1b[31mTicker: ${ticker}\nError: \x1b[0m\n${err}`);
     // Add ticker to retry list.
     data.retries.push(ticker);
     reject(err);

src/findHits.js

@@ -1,12 +1,13 @@
 const daysBetween = require('./daysBetween.js');
 const data = require('./stockData.js');
+const log = require('./logger.js');
 
 // A 'hit' is a pivot near the same price range as the current pivot.
 // Finds and stores all prior hits, recent hits, and recent hits on decreasing volume.
 // Scans an array of pivots for a single ticker.
 function findHits(ticker, direction, pivots) {
   if (!['long', 'short'].includes(direction)) {
-    return console.error('Must specify "long" or "short".');
+    return log('warn', 'Must specify "long" or "short".');
   }
   const pivot = direction === 'long' ? 'l' : 'h';
 

src/logger.js

@@ -0,0 +1,64 @@
+const fs = require('fs');
+const config = require('../config.js');
+const folderPath = 'logs';
+let logFolderExists = false;
+
+
+const logger = (level,  message, extra) => {
+  // Filter out any logging levels not set in config file.
+  if (!config.logLevels.includes(level)) {
+    return;
+  }
+  // Create the log files folder if it doesn't exist.
+  initLogFolder(folderPath);
+
+  // Format the message.
+  const output = format(level, message, extra);
+  // Write to screen.
+  console.log(output);
+  // Write to file.
+  const date = new Date().toISOString().slice(0, 10);
+  const fileName = `${date}.txt`;
+  const filePath = `${folderPath}/${fileName}`;
+  // Create a file with today's date if it doesn't exist.
+  if (!fs.existsSync(filePath)) {
+    console.log(`${filePath} doesn't exist. Creating...`);
+    fs.writeFileSync(filePath, '', 'utf8');
+  }
+  fs.appendFile(filePath, output, (err) => {
+    if (err) {
+      console.error(err);
+    }
+  });
+};
+
+
+// Creates the folder at folderPath if it doesn't yet exist.
+function initLogFolder(path) {
+  if (logFolderExists) {
+    return;
+  }
+  if (!fs.existsSync(path)) {
+    console.log(`Logs folder doesn't exist. Creating...`);
+    fs.mkdirSync(path, (err) => {
+      if (err) {
+        return console.error(err);
+      };
+    });
+    logFolderExists = true;
+  }
+}
+
+
+// Handles formatting for log messages.
+function format(level, message, extra) {
+  const now = new Date().toISOString();
+  let formattedOutput = `${now}::${level.toUpperCase()}::${message}\n`;
+  if (extra !== undefined) {
+    formattedOutput += `${extra}\n`;
+  }
+  return formattedOutput;
+};
+
+
+module.exports = logger;

src/parseRawData.js

@@ -1,3 +1,4 @@
+const log = require('./logger.js');
 // Takes a parsed JSON object, and transforms it.
 // (Passed as the 'transform' option to request-promise.)
 function parseRawData (stock) {
@@ -22,8 +23,7 @@ function parseRawData (stock) {
     return transformed.reverse();
   }
   catch (error) {
-    console.log('Transform error. Got:');
-    console.log(error);
+    log('warn', `Transform error: ${error}`);
   }
 }
 module.exports = parseRawData;